Category Archives: Supplements

BCAA’s: a smart marketing trick?

By Fleur van Griensven

BCAA’s are thought to put you in an anabolic state. Some people claim that you should use them before training when you are in a fasted state to prevent muscle loss. Is this true and should we all run to the nearest shop to spare our gains? Or is it just a smart marketing strategy from producing companies?


What are BCAA’s?

BCAA’s are branched-chain amino acids. These amino acids are branched (in Dutch vertakt), which in comparison to other amino acids makes it easier for enzymes to digest. Amino acids are the building blocks of proteins. When we consume protein our body uses specific enzymes which breaks these down into smaller units, the amino acids. There are 20 amino acids which can be converted into one another. At least, that’s true for the non-essential ones. The essential amino acids need to be present in our food because the body can’t synthesize them itself. There are 8 essential amino acids: Lysine, Tryptophan, Phenylalanine, Leucine, Isoleucine, Threonine, Methionine and Valine.

The three BCAA’s are Leucine, Isoleucine and Valine. During intensive activity, muscles will convert these quickly into energy. BCAA’s are supplemented just before or during training. The reason for supplementation is to stop muscle breakdown, recover quicker and in the long run build more muscle mass and strength. [1]

Are BCAA’s useful?

Many studies have been done on BCAA’s. A lot of people claim that you should take them before training fasted or during training. Some studies do find an effect of supplementation, whilst others don’t. There are many promising abstracts, but they are almost always hampered by lack of dietary control and/or a low protein intake. Making real conclusions based on these studies is hard.

The effectiveness of BCAA supplementation to reduce exercise-induced muscle soreness is mixed. One randomized placebo controlled study compared a BCAA’s + carbohydrate versus a carbohydrate sports drink following 3 days of intense weight training. BCAA + carbohydrate supplementation did not improve markers of muscle damage/soreness compared to carbohydrates only. [2]

A randomized, double-blind, placebo controlled study concluded the opposite. Participants received a BCAA supplement or a placebo. Before and after the damaging exercise (100 drop-jumps) they measured different muscle damage variables. They concluded that BCAA administered before and following damaging resistance exercise reduces markers of muscle damage and accelerates recovery in resistance-trained males. This might be due to greater bioavailability of substrate to improve protein synthesis. [3]

Research which shows a net anabolic effect of BCAA supplementation before, during or after training is often used to sell these powders [4]. Supplementing BCAA’s would eventually increase build-up of muscle. No evidence supports that ingestion of BCAA supplements is more effective than consuming a proper amount of food (protein) with respect to building muscle. In fact, there’s research to the contrary: food, and whey protein specifically, may be even more effective than a BCAA drink [5]. This is why you can consume a whey shake before training to get into a net anabolic state. It’s cheaper than BCAA powders, comes in many delicious flavours and is more effective.

What are the costs of BCAA’s?

BCAA’s can be bought in shops and online. The prices differ per brand and they sell both powders as tablets. For example, BCAA’s from Body & Fitshop will cost you €14,90 for 500 grams. The recommended daily serving is 20 grams before or during training, so a package lasts for about 25 days. Thus, quite expensive.

The amino acids shown in the picture above (Amino X from BSN) are even more expensive. You pay €19,90 for 435 grams. The daily serving is 29 grams, so you would pay €1,33 on a daily. Are these any better than Body & Fitshop own label? They both contain the three amino acids L-leucine, L-isoleucine and L-valine but probably in a bit different ratio. The Amino X also contains L-alanine, Taurine and L-arginine and vit D3 + vit B6. Will this add any effect to the product itself? Not sure, but you will just pay for something extra next to the BCAA’s you actually want to buy.

Selling BCAA’s on the market is a smart marketing strategy, because you basically pay for only three amino acids with a bit of a nice flavour added to it. Companies make good use of this by slogans as: ‘Amino X BSN, next level technology!’ or ‘BCAA Sensation V2 only contains the perfect ratio amino acids’. Yeah right if this would all be true, would just not one product with everything be enough? Companies try to come up with new things to make us consumers think that we just have to buy the new product. Smart marketing strategy it is!

Conclusion, BCAA’s: a smart marketing strategy?

Concluded can be so far:

  • The studies find a mixed effect of supplementation, but if they do find an effect are lacking in many aspects.
  • They are a smart marketing strategy.
  • They are expensive.
  • You can get your BCAA’s from food instead which is cheaper and more satisfying.BCAAs_2In general, there are studies that seem to show promising effects of supplementation. These however are hampered when taking a closer look. A whey shake just before training has shown to be even more effective in provoking a net anabolic response.

    If you think that you need to take a serving of BCAA’s before training fasted, first ask yourself the following. Is training fasted going to be any better in losing fat than having a meal and smash the hell out of your cardio session? An article about fasted morning cardio might follow, but at the end of the day it still comes down to being in a negative energy balance. If you enjoy doing cardio first thing in the morning go ahead, but don’t get deceived by this BCAA marketing strategy, drink a whey shake and save yourself money!


    [1] BCAA. Retreived from:

    [2] Wesley C. Kephart et all (2016). Post-exercise branched chain amino acid supplementation does not affect recovery markers following three consecutive high intensity resistance training bouts compared to carbohydrate supplementation. Journal of the International Society of Sports Nutrition.

    [3] Glyn Howatson et all (2012). Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study. Journal of the International Society of Sports Nutrition

    [4] Sharp CP, Pearson DR (2010). Amino acid supplements and recovery from high-intensity resistance training. Journal Strength Conditioning Research.

    [5] Hulmi JJ et all (2010). Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein. Nutrition & Metabolism.



Beta-alanine for strength training: yay or nay?

By Wietse In het Panhuis

If you have been training for some time, you have probably heard about it before. If you ever used pre-workout, you probably felt its effects before. I am talking about beta-alanine. Beta-alanine has been shown to be effective for some sports. The question is: Can beta-alanine supplementation be beneficial for strength training?Beta_alanine_1

What is beta-alanine?
Beta-alanine is a non-essential amino acid, which means that it is naturally present in the body. Even though it is already present in the body, supplementation with the intention to increase its levels could be beneficial (just like creatine). Beta-alanine is often used in sports that involve high intensity exercises, such as rowing and short-distance ice-skating. It is believed to combat muscle fatigue, and thereby has a positive effect on muscle endurance. Science has shown that beta-alanine is especially interesting for endurance during high intensity sports, and not for endurance (e.g. long distance running) and explosive (e.g. shot-put) sports[1].

How does beta-alanine improve endurance?    
Endurance is improved when fatigue is inhibited. There are many processes during exercise that could lead to fatigue. One of those processes is acidification of the muscles due to buildup of H+-ions (hydrogen ions) and lactate. Of course, the body has many mechanisms to prevent and counteract acidification, to make the pH (a measure of acidity) neutral again. Such mechanisms are called buffer mechanisms. In one of those mechanisms, a protein called carnosine plays a role[1]. During the production of ATP (energy production from food), H+-ions are formed. During exercise, a lot of energy is produced, and therefore also a lot of H+-ions. This will lead to a drop in pH (and will thus be more acidified). Carnosine works as a buffer by reacting with H+-ions. In that way, acidification and thereby fatigue of the muscles will be inhibited, which results in increased endurance.

Now beta-alanine comes in the picture. Beta-alanine supplementation results in increased carnosine levels[2]. Greater carnosine levels have been shown to increase endurance during high intensity exercise with a short duration, such as rowing and sprinting, like mentioned before. This raises the question: why not just supplement carnosine? This will not be effective, since muscle cells cannot take up carnosine from the blood stream[3]. The only way to increase carnosine inside the muscle cells, is if carnosine is produced (synthesized) in the cells themselves. Carnosine can be synthesized from beta-alanine and L-histidine (an amino acid), which in turn cannot be produced by muscle cells, but they can be taken up from the blood by muscle cells[4]. There is more L-histidine than beta-alanine in the blood, and the enzyme that combines these two to form carnosine, binds more easily to L-histidine than to beta-alanine[5-7]. For these two reasons, enough L-histidine is present while beta-alanine is often in shortage when carnosine is being produced (in other words: beta-alanine is the limiting factor). This means, that only beta-alanine is necessary to increase carnosine levels.

Thus, beta-alanine supplementation increases carnosine levels in the muscles. In turn, carnosine  works as a buffer to stabilize the pH and thereby endurance is increased. This is illustrated in Figure 1.


Figure 1. Beta-alanine’s mode of action. Retrieved from

How much beta-alanine do you need to use to see results?       
Increasing carnosine levels in the muscle cannot by achieved by taking beta-alanine once. According to scientific studies, supplementing 6,4 grams for 4 weeks is the most effective strategy to increase the carnosine levels in the muscle (by 65%)[8]. When supplementing for longer than 4 weeks, this will be equally effective and thus gives the same results. It just implies that supplementing beta-alanine for a short time period (less than 4 weeks) is not very effective.

The supplement is safe, but you may get a tingling, itching feeling on your skin (paresthesia) when you take more than 10 mg/kg body weight at once (around 800 mg). To prevent this, you can take eight daily dosages of 800 mg. Alternatively, four doses of 1600 mg of slow-release capsules also works to get the same effect without experiencing paresthesia[8]. Beta-alanine is commercially available in powder or slow release capsules. Powder costs about €16,- per 500 grams or ~€5,-/month. Slow-release capsules are about €15,- for 90 capsules or ~€20,-/month, making slow-release capsules four times as expensive as powder.

Fun fact: Beta-alanine is often present in pre-workout, but since intramuscular carnosine levels cannot be increased by taking beta-alanine once (like you do with pre-workout), this beta alanine has no added benefit to the pre-workout. Since beta-alanine dosages are often above 800 mg in pre-workout, this often results in paresthesia. Concluding: beta-alanine in pre-workout is useless and only gives you itches.

Can beta-alanine improve workouts for strength training?         
Unfortunately, in order to draw clear conclusions on this topic, more scientific research should be done. There are however a few studies that investigated this. One study looked at the effect of beta-alanine during a 10 week training program[9]. This study showed that total working volume increases due to beta-alanine. This effect only occurs during high-repetition sessions (8-12 repetitions) with little rest (30-90 seconds) and not in low-repetition sessions (±5 repetitions) with long rest (2-5 minutes)[9,11]. This makes sense, as during bodybuilding, muscles will get acidified which quickly can result in fatigue. Since beta-alanine improves the buffer capacity of the muscle by increasing carnosine levels, more repetitions can be done before reaching failure. In general, a greater training volume results in increased muscle mass. However, so far it has not yet been proven that the usage of beta-alanine supplements improves the gaining of muscle mass[10-12]. This might be due to the fact that in the performed studies training schedules varied and also included sets with fewer repetitions.

Thus, beta-alanine mainly seems to work for high intensity exercise during which glycolysis plays a major role (exercise durations of 1-6 minutes), since beta-alanine supplementation increases the muscle’s acid buffer capacity. Beta-alanine does not increase strength (like creatine does). Therefore, beta-alanine might be useful for bodybuilders (or for sports like bootcamp), but not for powerlifters or any sport that requires short bursts of energy (such as shot-put). More studies that test long term beta-alanine supplementation during a bodybuilding training schedule should be conducted to get clear answers on how much bodybuilders could benefit from beta-alanine.

Beta-alanine: yay or nay? Yay AND nay!      


It is both yay and nay, because there is not a clear answer.


  • Beta-alanine might improve endurance in bodybuilders, bootcampers and other high-intensity sports.


  • Beta-alanine supplementation does not increase strength.
  • Evidence for increases in muscle mass is lacking (even though it is likely).
  • In addition, supplementation can be either expensive or really inconvenient. Since beta-alanine can have paresthesia as a side effect at high dosages, supplementing about 6.4 grams per day without experiencing paresthesia can be done in three ways[8]:
  1. The cheapest option is to supplement 8 servings of 800 milligrams distributed over the day.
  2. If you do not like regular supplementation, you might consider two daily servings of slow-release capsules (which is however four times as expensive).
  3. Finally, you might just take 5 grams of powder in one or two servings per day, with the disadvantage of itches which may last up to one hour.

In summary, beta-alanine probably has some beneficial effects for bodybuilders by increasing volume and thereby possibly muscle mass. However, more scientific studies should be done to be sure. Please take into account that effects of single supplements are generally relatively small: The greatest improvements come from a good training schedule and good nutrition. Thus, as long as you are on amateur level of training, supplements in general will not make great differences. For professional athletes it can be more useful, since small differences could make the difference between winning or losing a competition. If you are not a pro, but if you want to improve in sports as much as you can, of course that’s fine. If you think it is worthwhile to either regularly supplement, pay a lot of money or experience itches, beta-alanine might be a good contribution to your workout.

[1] Artioli, G. G., Gualano, B., Smith, A., Stout, J., & Lancha Jr, A. H. (2010). Role of beta-alanine supplementation on muscle carnosine and exercise performance. Med Sci Sports Exerc, 42(6), 1162-1173.
[2] Suzuki, Y., Ito, O., Mukai, N., Takahashi, H., & Takamatsu, K. (2002). High level of skeletal muscle carnosine contributes to the latter half of exercise performance during 30-s maximal cycle ergometer sprinting. The Japanese journal of physiology, 52(2), 199-205.
[3] BAUER, K., & SCHULZ, M. (1994). Biosynthesis of carnosine and related peptides by skeletal muscle cells in primary culture. European journal of biochemistry, 219(1‐2), 43-47.
[4] Matthews, M. M., & Traut, T. W. (1987). Regulation of N-carbamoyl-beta-alanine amidohydrolase, the terminal enzyme in pyrimidine catabolism, by ligand-induced change in polymerization. Journal of Biological Chemistry, 262(15), 7232-7237.
[5] Harris, R. C., Tallon, M. J., Dunnett, M., Boobis, L., Coakley, J., Kim, H. J., … & Wise, J. A. (2006). The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino acids, 30(3), 279-289.
[6] Horinishi, H., Grillo, M., & Margolis, F. L. (1978). Purification and characterization of carnosine synthetase from mouse olfactory bulbs. Journal of neurochemistry, 31(4), 909-919.
[8] Harris, R. C., Tallon, M. J., Dunnett, M., Boobis, L., Coakley, J., Kim, H. J., … & Wise, J. A. (2006). The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino acids, 30(3), 279-289.
[9] Hoffman, J., Ratamess, N., Kang, J., Mangine, G., Faigenbaum, A., & Stout, J. (2006). Effect of creatine and ß-alanine supplementation on performance and endocrine responses in strength/power athletes. International journal of sport nutrition and exercise metabolism, 16(4), 430-446.
[10] Hoffman J, Ratamess NA, Ross R, Kang J, Magrelli J, Neese K, Faigenbaum AD, and Wise JA. Beta-alanine and the hormonal response to exercise. Int J Sports Med 29: 952–958, 2008.
[11] Hoffman JR, Ratamess NA, Faigenbaum AD, Ross R, Kang J, Stout JR, and Wise JA. Short-duration beta-alanine supplementation increases training volume and reduces subjective feelings of fatigue in college football players. Nutr Res 28: 31–35, 2008.
[12] Kendrick, I. P., Harris, R. C., Kim, H. J., Kim, C. K., Dang, V. H., Lam, T. Q., … & Wise, J. A. (2008). The effects of 10 weeks of resistance training combined with β-alanine supplementation on whole body strength, force production, muscular endurance and body composition. Amino acids, 34(4), 547-554.


Creatine, a beneficial peptide

by Ricky Siebeler

Creatine is a peptide composed of several amino acids. Specifically, the compound contains L-arginine, glycine and methionine. Currently it is one of the most used supplements by strength athletes, as it accelerates the recovery of available energy in the cells. Whether you are currently supplementing with creatine or not, your body already uses this compound on a day to day basis. These days there is even some evidence suggesting that creatine has potential benefits for non-athletes. Everything mentioned above explains why it is one of the most studied supplements available. This article will offer some in-depth information about the supplementation of creatine monohydrate, with some additional myth busting.

How does it work?

Without going too in-depth about the body’s energy systems; the body breaks down nutrients such as carbohydrates, fats and ketones to produce ATP (adenosine triphosphate). ATP is used by the cells as a source of energy. By breaking the bond between one of the phosphates, energy is released. This will convert ATP into ADP (adenosine diphosphate) and AMP (adenosine monophosphate). In order to keep a constant supply of energy in the cells, the precursors (ADP & AMP) need to be converted back into ATP.


The body does so by creating a high energy body between the precursors and phosphate groups. Creatine supplementation aids in the acceleration of this process, but before it is able to do so, it is phosphorylated into phosphocreatine by creatine kinase [1-3]. Phosphocreatine aids in this process by increasing the pool of available phosphate groups [4].


Effects of supplementation

As mentioned before, creatine is one of the most studied supplements available. This results in countless studies, aimed towards different effects. This section will only feature studies of importance to strength athletes.

Creatine supplementation has been proven to increase muscle creatine content by a significant amount, proving the effectiveness of supplementation [5-6]. There is also some evidence suggesting that creatine non-responders do exist, who will not benefit from supplementation [7]. There are currently over 60 studies showing a very significant increase in strength levels, after supplementation with creatine. Meta-analyses show effects ranges upwards to about a 7,5% increase in strength [8-9]. As result from creatine supplementation, some water retention may occur, of which the amount differs greatly from person to person. Contradictory to what most people suggest, creatine could be beneficial for more moderate intensity (such as lifting or exercising in the higher rep ranges) athletes as well [10-11]. So far, some of the studies suggest that creatine may also be significantly beneficial when training outside common strength training repetition ranges, these effects seem to get smaller with each additional decrease in intensity. Example: powerlifters get the most benefits, sprinters some benefits, and endurance runners no benefits.

How to supplement with creatine

In order to benefit the most from creatine supplementation, the muscles need to be fully saturated with creatine. In order to achieve/maintain this saturation, creatine is often supplemented each and every day.  Creatine can be supplemented through a loading protocol, or without one. The reason for using a loading protocol could be to reach a saturated state early on, and benefit from the supplementation as fast as possible [12]. Some downsides of using a loading protocol would be the possible discomfort in the digestive tract, and the additional costs of using a higher dosage. A typical loading protocol would be to supplement with about 0,3g/per kilogram of bodyweight per day, for about one week [13], followed by a maintenance dose of about 0,03g/per kilogram of bodyweight per day for the remainder of the cycle, or indefinitely [12]. When not using the loading protocol, just start with the maintenance dose which will yield the same effect, after a couple of weeks. Maintenance dose calculations will probably result in a much lower dosage than the generally recommended 5g dose. The 5g dosage is usually taken for one of the following reasons: creatine is very cheap, there is some research suggesting a possible minor benefit to higher dosage supplementation, scoop size, and to make the supplement companies more money.

Additional supplementation tip: Digestive tract discomfort may occur when supplementing without sufficient water intake. Some people may even experience diarrhea or nausea. These effects are more present when using a loading protocol. To counteract some of these effects, drink enough water and perhaps spread out the supplementation over several meals.

Creatine myths

  1. Since creatine is produced by the body, supplementation will suppress the body’s ability to produce its own creatine.

Research does suggest that the production of creatine will be inhibited, if the amount of supplemented creatine is able to cover the vital needs. This inhibition may actually be beneficial to general health, mainly because of the costs (such as essential amino acids) associated with the synthesis of creatine by the body. So far, research suggest that creatine production will go up to baseline levels again when the supplementation is discontinued [14-16].

  1. Creatine may be damaging to the body in the long-term.

There have been several studies testing the safety of long-term supplementation with creatine. Examples of these studies would be the supplementation of 5g on older adults and athletes for about one year. These studies found no negative effects of supplementation [14-16]. This suggests there is no need to cycle creatine out of safety reasons. Some people claim that creatine could be damaging to the liver. This claim is based on the fact that creatine will increase the blood creatinine levels, which are often used as a marker of liver damage. When supplementing with creatine, this marker becomes useless.

  1. There are different forms of creatine available, which lead to better results than creatine monohydrate.

There are countless different forms of creatine on the market today, some of the most well know being: buffered creatine, creatine nitrate, creatine ethyl ester, liquid creatine, and creatine HCl. These are generally being marketed as more potent or better digestible than creatine monohydrate. Some of these forms of creatine have been studied fairly well, and show no significant benefit over creatine monohydrate [6,17-18]. Even though some forms of creatine may be better in theory, so far research suggests otherwise. These forms of creatine are often several times more expensive than creatine monohydrate. Keep in mind that most of the countless studies on the efficacy and safety of creatine were conducted on creatine monohydrate.

  1. My daily meat consumption will provide enough creatine, I don’t need to supplement with creatine for the additional benefits.

According to the previously established maintenance dosage an average 85 kg person would need about 2,5g/per day, while an average person (American) only consumes about 0,85g/per day. Some meats have been shown to contain relatively much creatine: beef 5g/kg, chicken 3,4g/kg. Keep in mind that these numbers are for the uncooked meat, cooking them would denature most of the creatine [19]. Unless you are into consuming a lot of medium rare chicken, supplementation would be needed to attain most of the benefits.

  1. I need to take my creatine after my workout, with carbohydrates.

Timing of creatine has not been proven to be of importance. In theory the body could be more susceptible to the uptake of nutrients after a workout, even though the effects would be minor. Carbohydrates may also slightly improve the uptake of creatine [20]. Both of these effects will not make a difference in the effects of creatine. However, they could aid in decreasing the digestive tract discomfort caused by a creatine loading phase, but during the maintenance phase the factors will not make any difference.

  1. alcohol will diminish the effects of creatine.

Currently there is no research on the specific interaction between alcohol and creatine supplementation. Therefore we are not able to draw any conclusions about this topic, however we are able to hypothesize what kind of interaction we can expect. The uptake and storage of creatine requires water, while alcohol has a diuretic effect. This leads us to believe that alcohol does negatively affect the creatine supplementation. The next question would be to what extent this will affect the benefits of supplementation. Well consider the following: once you consumed the required amount alcohol to dehydrate yourself, you will probably not be able to properly train anyway. When consuming alcohol with moderation (which is not that much), creatine levels should not be affected significantly.

Take home messages:

– To get the most benefits from creatine for the least amount of money, use 3-5g of creatine monohydrate per day, timing does not matter.

– Continued usage for over a whole year have been shown to be safe (at normal dosages).

– Creatine ingested from diet alone is not significant in a normal diet (no medium rare chicken).


[1]          Mujika I, Padilla S. Creatine supplementation as an ergogenic aid for sports performance in highly trained athletes: a critical review. Int J Sports Med. 1997;18(7):491-6.

[2]          Terjung RL, Clarkson P, Eichner ER, et al. American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc. 2000;32(3):706-17.

[3]          Guzun R, Timohhina N, Tepp K, et al. Systems bioenergetics of creatine kinase networks: physiological roles of creatine and phosphocreatine in regulation of cardiac cell function. Amino Acids. 2011;40(5):1333-48.

[4]          Adhihetty PJ, Beal MF. Creatine and its potential therapeutic value for targeting cellular energy impairment in neurodegenerative diseases. Neuromolecular Med. 2008;10(4):275-90.

[5]          Del favero S, Roschel H, Artioli G, et al. Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance. Amino Acids. 2012;42(6):2299-305.

[6]          Spillane M, Schoch R, Cooke M, et al. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels. J Int Soc Sports Nutr. 2009;6:6.

[7]          Syrotuik DG, Bell GJ. Acute creatine monohydrate supplementation: a descriptive physiological profile of responders vs. nonresponders. J Strength Cond Res. 2004;18(3):610-7.

[8]          Branch JD. Effect of creatine supplementation on body composition and performance: a meta-analysis. Int J Sport Nutr Exerc Metab. 2003;13(2):198-226.

[9]          Dempsey RL, Mazzone MF, Meurer LN. Does oral creatine supplementation improve strength? A meta-analysis. J Fam Pract. 2002;51(11):945-51.

[10]       Graef JL, Smith AE, Kendall KL, et al. The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial. J Int Soc Sports Nutr. 2009;6:18.

[11]       Mcconell GK, Shinewell J, Stephens TJ, Stathis CG, Canny BJ, Snow RJ. Creatine supplementation reduces muscle inosine monophosphate during endurance exercise in humans. Med Sci Sports Exerc. 2005;37(12):2054-61.

[12]       Kilduff LP, Pitsiladis YP, Tasker L, et al. Effects of creatine on body composition and strength gains after 4 weeks of resistance training in previously nonresistance-trained humans. Int J Sport Nutr Exerc Metab. 2003;13(4):504-20.

[13]       Burke DG, Chilibeck PD, Parise G, Candow DG, Mahoney D, Tarnopolsky M. Effect of creatine and weight training on muscle creatine and performance in vegetarians. Med Sci Sports Exerc. 2003;35(11):1946-55.

[14]       Groeneveld GJ, Beijer C, Veldink JH, Kalmijn S, Wokke JH, Van den berg LH. Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. Int J Sports Med. 2005;26(4):307-13.

[15]       Shao A, Hathcock JN. Risk assessment for creatine monohydrate. Regul Toxicol Pharmacol. 2006;45(3):242-51.

[16]       Bender A, Samtleben W, Elstner M, Klopstock T. Long-term creatine supplementation is safe in aged patients with Parkinson disease. Nutr Res. 2008;28(3):172-8.

[17]       Jagim AR, Oliver JM, Sanchez A, et al. A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate. J Int Soc Sports Nutr. 2012;9(1):43.

[18]       Jäger R, Harris RC, Purpura M, Francaux M. Comparison of new forms of creatine in raising plasma creatine levels. J Int Soc Sports Nutr. 2007;4:17.

[19]       Mora, L., M.A. Sentandreu, and F. Toldra, Effect of cooking conditions on creatinine formation in cooked ham. J Agric Food Chem, 2008. 56(23): p. 11279-84.

[20]       Green AL, Hultman E, Macdonald IA, Sewell DA, Greenhaff PL. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. Am J Physiol. 1996;271(5 Pt 1):E821-6.

Zinc supplementation: Worth the money?

By Fleur van Griensven


According to a recent poll and survey, you guys wanted to know more about zinc supplementation, so here you go! It’s a mineral not spoken much of, but that doesn’t necessary mean we should forget about it. What does this mineral do in the body? Are there any consequences of a low intake? Is zinc supplementation useful? You can read it all in this article: Zinc supplementation: worth the money?

What is Zinc?

Zinc is a mineral which is part of the trace elements in nutrition. Trace elements are minerals that are present in very small quantities in our diet, but are nonetheless essential. Other examples of trace elements are iodine and selenium.

Zinc is an essential element for hundreds of proteins in the body, including numerous enzymes and DNA-binding proteins. A few examples of proteins that contain zinc are the receptors for vitamin A and vitamin D. It also plays a role in immune function, wound healing and cell division. On top of that it also supports normal growth and development during pregnancy, childhood and adolescence[1].

Zinc can be found naturally present in some foods, it can be added to food,  and it can be available as a dietary supplement. A wide variety of foods contain zinc. See table 1 below for an overview of the foods naturally containing zinc. Besides red meat and poultry, oysters are a great zinc source. Other good sources include nuts, beans, seafood, whole grains and dairy products.

Table 1: Food sources of Zinc[2].

Food Milligrams (mg)
per serving
Percent DV*
Oysters, cooked, breaded and fried, 3 ounces 74.0 493
Beef chuck roast, braised, 3 ounces 7.0 47
Crab, Alaska king, cooked, 3 ounces 6.5 43
Beef patty, broiled, 3 ounces 5.3 35
Breakfast cereal, fortified with 25% of the DV for zinc, ¾ cup serving 3.8 25
Lobster, cooked, 3 ounces 3.4 23
Pork chop, loin, cooked, 3 ounces 2.9 19
Baked beans, canned, plain or vegetarian, ½ cup 2.9 19
Chicken, dark meat, cooked, 3 ounces 2.4 16
Yogurt, fruit, low fat, 8 ounces 1.7 11
Cashews, dry roasted, 1 ounce 1.6 11
Chickpeas, cooked, ½ cup 1.3 9
Cheese, Swiss, 1 ounce 1.2 8
Oatmeal, instant, plain, prepared with water, 1 packet 1.1 7
Milk, low-fat or non fat, 1 cup 1.0 7
Almonds, dry roasted, 1 ounce 0.9 6
Kidney beans, cooked, ½ cup 0.9 6
Chicken breast, roasted, skin removed, ½ breast 0.9 6
Cheese, cheddar or mozzarella, 1 ounce 0.9 6
Peas, green, frozen, cooked, ½ cup 0.5 3
Flounder or sole, cooked, 3 ounces 0.3 2

*DV=Daily Value. The Daily Value by the U.S. Food and Drug Administration is 15 mg for adults and children older than 4 year. Note: Food labels do not need to list zinc content unless it is a fortified product.

Phytates, which are compounds presents in whole-grain breads, cereals, legumes (for example spinach) and some other foods, inhibit zinc absorption. This leads to a difference in bioavailability of zinc from plant foods compared to animal foods. Bioavailability is the fraction of the dose which you take that reaches the systemic circulation (blood circulation). This might seem rather complicated but I’ll try to explain it more clearly. When some medication is administered intravenously (directly into a vein) its bioavailability is 100% because it directly reaches the blood circulation. However, when a medication is administered orally its bioavailability is lower, since not all of it is absorbed in the intestine. Take home point: the bioavailability of zinc from plants foods is lower due to the fact that they inhibit zinc absorption, although many plant based foods are still good sources of zinc.

Supplements contain several forms of zinc, for example zinc gluconate, zinc sulfate and zinc acetate. In each of these forms the percentage of elemental zinc varies, but the elemental zinc content always appears on the supplement container. Research has not yet shown and determined whether differences exist among these forms of zinc in absorption and bioavailability.

Recommended intake

Zinc intake recommendations are provided in Recommended Dietary Allowances (‘Aanbevolen Dagelijkse Hoeveelheid’ in Dutch) developed by the Food and Nutrition Board (FNB). This is an average daily level of intake sufficient to meet the requirements of nearly all healthy individuals (97%). To see what the current RDA for zinc is, check table 2 below.

Table 2: RDA for zinc[2].

Age Male Female Pregnancy Lactation
0–6 months 2 mg* 2 mg*
7–12 months 3 mg 3 mg
1–3 years 3 mg 3 mg
4–8 years 5 mg 5 mg
9–13 years 8 mg 8 mg
14–18 years 11 mg 9 mg 12 mg 13 mg
19+ years 11 mg 8 mg 11 mg 12 mg

* Adequate Intake (AI)

What are consequences of a low zinc intake?

A zinc deficiency is characterized by growth retardation, loss of appetite and immune impairment. Especially immune impairment can lead to increased risk of getting infectious diseases. This is the case in developing countries as there is a bigger chance of zinc deficiencies. The prevalence (occurrence) of an inadequate zinc intake is >25% in Sub-Saharan and South Asia[3].  Most people in Western Countries and also the Netherlands have a wide variety of foods in their diet, which under normal circumstances should be enough to meet their RDI of zinc.

One study in 1995 made use of three conventional tests (serum, urine, and hair samples) in groups of Dutch children with symptoms common in zinc deficiency (diarrhea, recurrent infection, or growth retardation). From this study can be concluded that +/- 1% of Dutch children with minor complaints suffer from either acute or subacute zinc deficiency[4]. Thus zinc deficiency is not common among Dutch children.

There are more non-specific symptoms (weight loss, taste abnormalities and mental lethargy) which can result from a severe zinc deficiency, but these are often associated with other health conditions and a medical examination is needed in those cases.

Laboratory diagnosis of a zinc deficiency is difficult because zinc is distributed throughout the body and bound to various proteins. People can have symptoms of a zinc deficiency, but the laboratory tests might not confirm this.

However, there are some groups which may be at risk of zinc deficiency:

  • People with gastrointestinal diseases
  • Vegetarians
  • Pregnant women
  • Alcoholics

How about ZMA?

ZMA is a supplement widely used by bodybuilders these days. The supplement contains 2 minerals (zinc monomethionine aspartate and magnesium aspartate) and vitamin B6.  It’s a supplement which claims to promote recovery and additionally raises strength levels and enhance hormonal profiles. Most labels indicate that it should be taken in 60-90 minutes prior to bedtime on an empty stomach.

Several scientific studies have been done on the effects of ZMA. One study in 2009 gave athletes the daily recommended dose of ZMA and measured androgen levels during the next 56 days. ZMA supplementation showed no effect on androgen levels between the placebo and ZMA group, so ZMA doesn’t elevate androgen levels[5]. In addition, most people don’t benefit from zinc and vitamin B6 supplementation, because they already meet the Recommended Dietary Allowances. Magnesium deficiencies are more common however.

This is just my own experience: I’ve used ZMA for a month or so, when I was cutting back in the days. I always have some problems falling asleep when I go deeper into a cut (because of the hunger, which keeps me awake during the night) and wanted to try out if it was any good. It sure made my muscles relax a bit more, but later I realized that I was better and cheaper off by just buying magnesium Citrate. Magnesium supplementation will be discussed in another article soon.

There are some claimed benefits from taking a zinc supplement. First, it states to accelerate wound healing and therefore zinc is being used to treat skin conditions such as ulcers. Relatively few studies support this. A meta-analysis of 181 participants from six randomized controlled trials of oral zinc sulfate versus placebo for venous or arterial leg ulcers found no significant difference in time between intervention and placebo group[6].

Secondly there is the claimed benefit on growth. A meta-analysis of 33 randomized controlled trials enrolling prepubertal children from North and South America, Europe, Africa, and Asia who were at risk of zinc deficiency showed that zinc supplementation modestly enhanced linear growth and weight gain. Growth responses were greater in children with low initial weight-for-age and in those with low initial height-for-age[7]. This only means that zinc supplementation can prevent a growth retardation. If you aren’t zinc deficient, it won’t make you grow.

Conclusion, zinc supplementation: worth the money?

In the end we can conclude that zinc supplementation isn’t necessarily needed provided you consume a healthy diet with a variety of different food sources. Food sources like red meat, poultry, nuts, dairy and whole grains all contain small quantities of zinc. There are however some risk groups which can benefit from taking a zinc supplement.

If you yourself experience some of the symptoms described above which might indicate a zinc deficiency, go and get your blood levels checked to see if this really is the case. The claimed effects of zinc supplementation are mixed. Most studies did not found a significant effect on wound healing. However on growth we see a modest improvement in children who were at risk of zinc deficiency. Take into account that zinc deficiency is rare in our country. So there is no added benefit of supplementing without actually suffering a zinc deficiency.

It can’t do any harm to eat more of the just mentioned food sources or take a zinc supplement if a deficiency really is the case. If not, you’re better off spending your money on food or other supplements which are in line with your personal situation!


[1] EDX Nutrition and Health part 2: Micronutrients and Malnutrition. Available online:

[2] National Institute of Health: Office of Dietary supplements. Available online:

[3] K. Ryan Wessells and Kenneth H. Brown (2012). Estimating the Global Prevalence of Zinc Deficiency: Results Based on Zinc Availability in National Food Supplies and the Prevalence of Stunting. PLoS One. 7(11)

[4] Van Wouwe JP (1995). Clinical and laboratory assessment of zinc deficiency in Dutch children. A review. Biol Trace Elem Res. 49(2-3): 211-25.

[5] Koehler K, Parr MK, Geyer H, Mester J, Schänzer W (2009). Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. European Journal of Clinical Nutrition. 63(1): 65-70

[6] Wilkinson EA1, Hawke CI (1998). Does oral zinc aid the healing of chronic leg ulcers? A systematic literature review. Arch Dermatol. 134(12): 1556-60

[7] Brown KH1, Peerson JM, Rivera J, Allen LH (2002). Effect of supplemental zinc on the growth and serum zinc concentrations of prepubertal children: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 75(6): 1062-71.

Fish oil (omega-3) supplements: Yay or nay?

By Wietse In het Panhuis

You might have heard about it quite often: fish oil. A lot of online experts claim fish oil is good for you. There are countless claimed effects of fish oil supplementation on health. Three examples of such claims are that fish oil is good for the immune system, it relieves depression and protects against cardiovascular disease. The question arises which claims have proven to be true, if any are true at all. Should we take these smelly rascals? In short: ‘fish oil: yay or nay?’.


What is fish oil?
Fish oil supplements consist of omega-3 fatty acids, which are polyunsaturated fatty acids (PUFAs). An unsaturated fatty acid has a double bond between two carbon atoms. The picture below shows the difference between saturated and unsaturated fatty acids. The ‘-‘ sign between two C’s (carbon atoms) means a single bond, and ‘=’ means a double bond. You can see that the saturated fatty acids are straight and stiff: they cannot bend. The unsaturated fatty acids are more flexible, since the double bond allows them to have a more bended structure. This bent structure is more healthy, as a straight structure is thought to pile up more easily in the blood vessel wall and thereby cause atherosclerosis (clogging of the arteries due to fat accumulation). This explains why unsaturated fatty acids are more healthy than saturated fatty acids.


Mono unsaturated fatty acids (MUFAs) have a single double bond and PUFAs have multiple double bonds, which increases the ability to bend even more, making PUFAs even healthier than MUFAs. Fats that contain unsaturated fatty acids have a lower melting point than saturated fatty acids. This explains why fats that consist mostly of unsaturated fatty acids (like most plant oils) are liquid at room temperature, while fats made out of saturated fatty acids (most animal-derived fats, like butter) are solid at room temperature. Fish oil is liquid at room temperature, which shows that it consists of unsaturated fatty acids[1]. Just a fun fact. Another fun fact: these differences in boiling points explain why oil smokes when being heated for too long during cooking, while butter does not.

For those who know little of chemistry, don’t worry. The chemistry part is over, and if you did not understand it, that doesn’t matter in order to understand the rest of the story.

Omega-3 fatty acids are essential fatty acids. They are essential because the body cannot produce them, which is why they have to be obtained from the diet. There are three types of omega-3 fatty acids which are of importance for humans: α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is derived from plant sources and can thus be found in foods such as nuts, seeds and seed oils. EPA and DHA are mainly present in fish and fish oils. Thus, when taking fish oil supplements, you ingest EPA and DHA[1].

What are the health effects of fish oil?
Omega-3 fatty acids, mainly EPA and DHA, have been linked to numerous health effects. There are a lot of health claims regarding the intake of these fatty acids, but they are not all true. The EFSA has extensively reviewed this and came to the conclusion that the intake of fish oil (supplements) has the following health effects[2]:

  1. EPA and DHA contribute to maintenance of the normal function of the heart (reduced heart rate and reduced risk of arrhythmia(=irregular heartbeats)). This effect already takes place with a daily intake of 250 mg.
  2. EPA and DHA are able to lower blood pressure. Blood pressure plays an important role in cardiovascular disease (CVD). Thereby, EPA and DHA decrease the risk of CVD. This effect takes place with a daily intake of 750 mg[3].
  3. EPA and DHA contribute to the maintenance of normal (=low) (fasting) blood concentrations of triglycerides (one glycerol attached to three fatty acids, in other words: fat), which means that they lower triglyceride levels. The levels of triglycerides (fats) in the blood are a (general) health marker. Having normal (low) blood concentrations of triglycerides lowers the risk of getting CVD. This effect takes place with a daily intake of 2 g.
  4. EPA and DHA can decrease thrombosis by functioning as blood thinners. This lowers the risk of stroke. This effect takes place with a daily intake of more than 4 g[3], which is considered to be very high.
  5. There might be several other health effects, but there is not enough evidence to support these claims.

In summary, up till now scientific evidence is only conclusive about the decreased risk of CVD with supplementation of fish oil, which is nonetheless a great health effect.

Conclusion – Fish oil: Yay or nay?



How much and which supplements should I take?
As said before, omega-3 supplementation can result in several health benefits. Different daily dosages are required in order to obtain these health effects. These values range from 250 mg per day to above 4 g per day. However, like any other nutrient: more is never better. There is an optimal intake, but if you exceed this intake, it might give adverse health effects. This is because a lot of fatty acids are made from other fatty acids in the body. This happens in an optimal ratio of EPA/DHA to other fatty acids. If you ingest too much EPA/DHA, the ratio between EPA and DHA gets out of balance. The FDA states that it is safe to consume up to 3000 mg of omega-3 per day[4], and the EFSA showed that supplementation of 5 grams of EPA and DHA is still safe[5].

Alternatively, these high daily intakes can be achieved by fish consumption. However, one would have to eat a lot of fish to get the same levels as taking fish oil capsules. Omega 3 is most abundant in mackerel, salmon, herring and tuna, which, if consumed fresh, contain around 1000-1500 mg of omega-3 fatty acids per 100 grams. Canned fish already contains less omega-3. Also, when fish is canned in oil, some of the omega-3 fatty acids might leak into the oil. If you discard the oil, you lose omega-3 fatty acids. Fish that is canned in water does not show this problem.

Here is a table that shows the omega-3 content of several types of fish:

If you look at the table, you can imagine that you have to eat fish almost daily to get the same levels of intake as when you take fish oil supplements. Of course, eating fish is highly recommended over taking supplements, as foods contain many more substances that can be healthy compared to supplements.

The average fish oil supplement has 1000 mg of fish oil per capsule, which contains approximately 550 mg of EPA/DHA. I would personally recommend to have a daily intake of 3 grams of fish oil, based on the health effects and the safety. Fish oil supplements are widely available, and have several brands. More expensive brands do not necessarily are of better quality than cheaper brands. However, there are some brands that make supplements according to the Current Good Manufacturing Practices (CGMP) of the Food and Drug Administration (FDA), meaning that these brands are trustworthy and are assured of good quality. Two of such brands are NOW and Solgar.

Last side note: There is one situation in which you should not take fish oil supplements, namely for cancer patients undergoing chemotherapy treatment. The fish oil can interfere with the chemotherapy, making the therapy possibly less effective. Thus, for cancer patients taking fish oil supplements is generally advised against. Also, when you have a blood pressure that is too low, fish oil supplements might not be a good idea as these lower blood pressure (even though this effect is small). If you have any doubts whether you should use fish oil supplements or not in a certain case, just ask your doctor!


[1] Whitney, E., & Rolfes, S. R. (2007). Understanding nutrition. Cengage Learning.
[2] EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and maintenance of normal cardiac function (ID 504, 506, 516, 527, 538, 703, 1128, 1317, 1324, 1325), maintenance of normal blood glucose concentrations (ID 566), maintenance of normal blood pressure (ID 506, 516, 703, 1317, 1324), maintenance of normal blood HDL-cholesterol concentrations (ID 506), maintenance of normal (fasting) blood concentrations of triglycerides (ID 506, 527, 538, 1317, 1324, 1325), maintenance of normal blood LDL-cholesterol concentrations (ID 527, 538, 1317, 1325, 4689), protection of the skin from photo-oxidative (UV-induced) damage (ID 530), improved absorption of EPA and DHA (ID 522, 523), contribution to the normal function of the immune system by decreasing the levels of eicosanoids, arachidonic acid-derived mediators and pro-inflammatory cytokines (ID 520, 2914), and “immunomodulating agent” (4690) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8(10):1796. [32 pp.]. doi:10.2903/j.efsa.2010.1796. Available online:
[3] Mozaffarian, D., & Wu, J. H. (2011). Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events. Journal of the American College of Cardiology58(20), 2047-2067.
[4] US Food and Drug Administration. (2004). FDA announces qualified health claims for omega-3 fatty acids. US Department of Health and Human Services.
[5] Agostoni, C., Bresson, J. L., Fairweather-Tait, S., Flynn, A., Golly, I., Korhonen, H., … & Neuhäuser-Berthold, M. (2012). Scientific opinion on the tolerable upper intake level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), Parma, Italy.

Multivitamin supplements: yay or nay?

By Wietse In het Panhuis


We are living in the time of the fit girls and the fit guys. Healthy aging, superfoods, and Green happiness. These words determine the trend we live in now. People are looking for ways to stay healthy and young. Everyone has probably heard of multivitamin supplements, and they are marketed as healthy and essential for development. It is general belief that these multivitamins are good, which is why a lot of people are using them. In the Dutch population, about 50% of the females and 33% of the men are using supplements, yet not even 20% of the people meets a fruit and vegetable intake according to the recommended daily intake[1]. Can a multivitamin supplement replace fruits and vegetables? Or should it only be used as an addition to your diet to improve health? Do they even work? And can they be harmful?

What are vitamins?       
Vitamins are (biochemical) compounds that are present in the body, as well as in food from which they can be derived. The body is an amazingly complex structure in which billions of reactions are taking place at this very moment. Think of things like metabolism, growth, immunity, DNA replication, and so much more. Vitamins play an important role in these processes. They are often involved in one or multiple different reactions (as a substrate or an enzyme). All in all, vitamins help the body to function[2].

Vitamins can either be hydrophilic (hydro=water, philos=loving; water-loving) or hydrophobic (hydro=water, phobos=fear; water-fearing). If you are not familiar with these terms, think of when you put oil and water in one glass as an example: the liquids will be separated, with the oil on top since it has a lower density than water. Thus, there are water-soluble vitamins and fat-soluble vitamins. Water-soluble vitamins include vitamins B and C, and fat-soluble vitamins include vitamins A, D, E, and K. One important difference between water- and fat-soluble vitamins is the foods they are present in. Fat-soluble vitamins are mainly present in food products that contain a lot of fat or oil, such as animal products (but also some vegetables, nuts, and seeds). Water-soluble vitamins are mainly present in foods that contain water (many foods such as fruits, vegetables, nuts, seeds, etcetera). A second important difference, is the way that these two types of vitamins are absorbed, transported, stored, and excreted. Mainly the latter two are of vital importance. Fat-soluble vitamins can be stored in body fat (in biological terms: adipose tissue), but water-soluble vitamins cannot be stored in the body. This means that excesses of water-soluble vitamins are excreted via the kidneys. In other words: when you ingest too much water-soluble vitamins, you will piss them out. Excesses of fat-soluble vitamins are stored in the adipose tissue of the body, which will in turn be used when the body needs these vitamins. This also means that when you ingest too much fat-soluble vitamins, the body cannot get rid of them[2]. Keep on reading to find out what the consequences are of this!

What are minerals?       
Minerals, just like vitamins, are involved in many processes of the body. In that respect, they are quite similar to vitamins. There are just some differences in the processes they are involved in. The main difference is the classification: minerals are simple atoms, while vitamins are more complex molecules. As minerals are soluble in water, they can be excreted through the urine, just like water-soluble vitamins[2]. Vitamins and minerals together are classified as micronutrients.

Do you need micronutrients?   
Surprise, surprise. Yes, you do! Vitamins and minerals are essential for vital functioning of the body. There are quite some diseases related to vitamin deficiencies (deficiency=shortage), such as scurvy from a vitamin C deficiency, rickets from a vitamin D deficiency, night blindness from vitamin A deficiencies, a lower bone mass from calcium deficiencies, and so on[2].

Luckily, these severe vitamin deficiencies are rare in the Western world, as the average diet contains enough vitamins and minerals to prevent these diseases from occurring. However, smaller, less severe, but not less relevant deficiencies occur frequently[3-5]. This could be caused by unbalanced diets that lack certain food categories (like vegetables, fruits, dairy, etcetera), examples of such diets can be vegetarian or vegan diets. Another cause is a lack of sunlight exposure. Such ‘small deficiencies’ will not result in disease, but they can result in some small (unnoticeable) side-effects, as well as suboptimal growth, recovery, etcetera. Having optimal intakes of vitamins and minerals thus could contribute to a good overall health.

What is the optimal dose of vitamins and minerals?     
In the past, there has been much evidence that certain vitamins can decrease the risk of getting specific types of cancer. This lead to the conduction of several randomized controlled trials[6-8]: studies during which one group of participants was given the vitamin supplement (the intervention group), and the other group served as a control, to compare in which group the most cancers would occur. The hypothesis was that there would be less cancer cases in the intervention group than in the control group. Several months or years later, results were in. It appeared that there were more cancers in the intervention group than in the control group. This means that the vitamin increased cancer risk instead of decreasing it. The researchers assumed that the vitamin would be good, since previous research indicated that.

These researchers made a big mistake, but it is not different from the reasoning people have in daily life. Namely if something is proven to be healthy, then more of it would probably be even healthier. However, this is not how vitamins (and actually all nutrients) work. Taking too much of anything can be toxic, but taking too little is also bad for your health. Thus, it depends on the amount (or the dose) whether something is healthy or unhealthy. This is nicely illustrated in the figure below (Figure 1).


Figure 1. The U-curve of vitamin and mineral intakes and disease

This figure is called a U-curve, with on the y-axis (vertical axis) the occurrence of disease (you can read it as healthy at y=0 and unhealthy at y=100), and on the x-axis (horizontal axis) the dose of intake of the vitamin (0 on the left means a dose of 0, the more to the right means a higher dose). On the left of the x-axis, there will be a lot of disease: very low intake (deficiency) causes disease. On the right side of the x-axis, there will be a lot of disease as well: too high intakes are toxic. In the middle there is the perfect intake: within these lower and upper boundaries (the safe or healthy margin), there will be no disease. As was discussed before, the body can get rid of water-soluble vitamins and minerals via the urine, but not of fat-soluble vitamins, as these are stored in the body fat. This explains why mainly fat-soluble vitamins can have toxic effects when consumed in high dosages, whereas water-soluble vitamins and minerals will not be as toxic but also result in some side effects. Such side effects differ per micronutrient, but the main message is that these side effects are not as severe or toxic as those of fat-soluble vitamins. Thus, the middle of the U-curve shows the safe or optimal intake which is most healthy. More or less is unhealthy! So, can vitamins and minerals cure diseases like aids or cancer (which is claimed sometimes)? No. When you are deficient in a certain vitamin it can cause a particular disease (in extreme cases, such as scurvy from a vitamin C deficiency), and increasing the intake of that vitamin can cure this particular disease again. However, taking 1 gram of vitamin C per day will not cure any other diseases. It will also not contribute to better health than regular doses.

Therefore, when we look back at the example given above, about the studies that showed that certain vitamins cause cancer, this makes sense. Figure 2 below illustrates a potential U-curve for one of the vitamins that showed this effect in such a study: folate[9,10].


Figure 2. Potential U-curve for folic acid intake and cancer risk.

As you can see, low intakes can increase cancer risk. Increasing intake can decrease cancer risk, but further increases increase risk again. There are many examples of vitamins that show such a curve. In conclusion: too high dosages of vitamins are toxic!

What should the intake of each vitamin and mineral be?            
The optimal intake differs per person, due to differences in age, gender, body composition, and genetics. Health institutes have come up with RDIs (Recommended Daily Intake, ADH (Aanbevolen Dagelijkse Hoeveelheden) in Dutch), which is a recommended level of intake, for each vitamin and mineral. The levels of the RDIs are high enough so that most of the population meets the individual optimal intake, while these are still within the safe limits of intake. Thus, consuming 100% of the RDIs of vitamins and minerals will make sure you have an optimal intake. Consuming more than the RDI will not lead to additional health benefits, and can possibly be unhealthy.

Multivitamin supplements        
So we know that we need approximately 100% of the RDI of each micronutrient every day. Can’t we just get this from multivitamin supplements? Multivitamins supplements contain all vitamins and minerals that we need. However, most multivitamins do not contain the right dosages. They are often dosed too high: they contain over 100% of the RDI of many micronutrients, which is too much. As was discussed before, this is unnecessary as it will not have any benefits over taking 100%, and it could lead to ‘overdosing’ as well. Also, even when these supplements contain the right amount of 100% of the RDI, you can still get too much of a micronutrient because these are abundantly present in your food.

Secondly, the beneficial effects, safety, composition and characteristics of multivitamins are not backed up by science[11]. They are simply produced by companies and marketed as healthy, so they made a supplement without hard evidence and knowledge on how to actually make a good-functioning supplement, of which its health effects are not proven by science.

Thirdly, a lot of vitamins and minerals interact with each other in the intestine. These interactions can decrease the absorption (also the bioavailability) of these vitamins and minerals. This means that they are not very well taken up in the blood[11]. For example, calcium is known to decrease the absorption of iron[2,12]. Thus, if you take a multivitamin supplement, a lot of these vitamins and minerals will interact with each other, which means that you will by far not get all these in your blood. Even though the package says you will get 100% of the RDI of a vitamin, chances are high you do not reach this 100%. This is the case for quite a lot of vitamins and minerals.

Fourthly, like mentioned before, multivitamins contain all micronutrients. It is possible that you have a deficiency in some micronutrients, but with the average diet, deficiencies in the vast majority of micronutrients will not occur. Therefore, supplementing these micronutrients is unnecessary and can also be unhealthy. As was discussed before, there are quite some cases that proved supplementation of certain vitamins increased the risk of getting cancer, showing the potential risks of overdosing supplements[6-8].

Lastly, as mentioned in the introduction, a lot of people take supplements but few people eat enough fruits and vegetables. That raises the question: can supplements replace fruits and vegetables? The answer is no, simply because fruits and vegetables (and food in general) consist of much more than only micronutrients. The fibers in fruits and vegetables are also very important in contributing to health, and fibers are not present in multivitamins. In addition, fruits and vegetables contain thousands very tiny compounds: phytochemicals. Phytochemicals are a hot topic. It is not exactly known which phytochemicals there are since there are so many, and what their role is in health. However, many of the health effects of fruits and vegetables are probably due to phytochemicals. Yet again, multivitamins do not contain these, showing that, simply said, you miss out on a lot of good stuff if you take supplements instead of fruits and vegetables. In conclusion: multivitamins (and thereby supplements in general) cannot replace food.

Thus, multivitamin supplements: yay or nay?   
Summing up what we have learned so far:

  1. Multivitamins are not well-tested, and the health effects and safety are not well backed-up by science.
  2. Multivitamins are unnecessary with a varied dietary pattern.
  3. Multivitamins cannot replace fruits and vegetables, as there are many other substances in fruits and vegetables, such as fibers and phytochemicals, that contribute to health, not only vitamins and minerals.
  4. Multivitamins combined with the regular dietary intake can result in vitamin levels that are above the safe level, which could lead to toxic effects.

NAY! Do not use multivitamin supplements!

If taking multivitamins is not advised, how to prevent vitamin or mineral deficiencies?              
As mentioned before, there are recommended daily intakes that tell you how much your vitamin and mineral intake should be. However, when you are not taking multivitamin supplements on which is nicely calculated how much vitamins and minerals they contain, how on earth will you get your daily 100% RDI intake? The only way to accurately do that, is by calculating how much of each food product you eat, and how much that product contributes to the RDI of every single vitamin and mineral. Probably, there is not a single person on earth who is taking the trouble to do this. It is not doable, and not necessary. The best way to make sure you get your vitamins and minerals is by eating a well-balanced diet. Not taking multivitamin supplements and adhering to the food recommendations of your country (such as eating enough vegetables, enough fruits, etcetera) and varying in what you eat (different vegetables/fruits every day) as much as possible will ensure that you get enough vitamins and minerals. Also, preventing too high intakes can be advised, as these can be unhealthy.

Does this mean that all vitamin supplements are useless? No. In some situations, specific groups (differences in age, gender, dietary status, pregnancy/lactation, etcetera) can benefit from vitamin supplementation. Discussing the use of all vitamins and minerals individually here would make this article too extensive, which is why we will write separate articles for each.

So, throw away your box of multivitamin supplements and eat your veggies!



[1] C.T.M. van Rossum et al. (2016). Results of the first two years of the Dutch National Food Consumption Survey 2012-2016. RIVM Letter report 2016-0082
[2] Whitney, E., & Rolfes, S. R. (2007). Understanding nutrition. Cengage Learning.
[3] Holick, M. F. (2007). Vitamin D deficiency. New England Journal of Medicine357(3), 266-281.
[4]  Antony, A. C. (2003). Vegetarianism and vitamin B-12 (cobalamin) deficiency. The American journal of clinical nutrition78(1), 3-6.
[5] Allen, L. H. (2009). How common is vitamin B-12 deficiency?. The American journal of clinical nutrition89(2), 693S-696S.
[6] Albanes, D., Heinonen, O. P., Huttunen, J. K., Taylor, P. R., Virtamo, J., Edwards, B. K., … & Palmgren, J. (1995). Effects of alpha-tocopherol and beta-carotene supplements on cancer incidence in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study. The American journal of clinical nutrition62(6), 1427S-1430S.
[7] Bairati, I., Meyer, F., Jobin, E., Gélinas, M., Fortin, A., Nabid, A., … & Têtu, B. (2006). Antioxidant vitamins supplementation and mortality: a randomized trial in head and neck cancer patients. International Journal of Cancer119(9), 2221-2224.
[8]  van Wijngaarden, J. P., Swart, K. M., Enneman, A. W., Dhonukshe-Rutten, R. A., van Dijk, S. C., Ham, A. C., … & Zillikens, M. C. (2014). Effect of daily vitamin B-12 and folic acid supplementation on fracture incidence in elderly individuals with an elevated plasma homocysteine concentration: B-PROOF, a randomized controlled trial. The American journal of clinical nutrition100(6), 1578-1586.
[9] Giovannucci, E., Stampfer, M. J., Colditz, G. A., Hunter, D. J., Fuchs, C., Rosner, B. A., … & Willett, W. C. (1998). Multivitamin use, folate, and colon cancer in women in the Nurses’ Health Study. Annals of internal medicine129(7), 517-524.
[10] Ebbing, M., Bønaa, K. H., Nygård, O., Arnesen, E., Ueland, P. M., Nordrehaug, J. E., … & Tverdal, A. (2009). Cancer incidence and mortality after treatment with folic acid and vitamin B12. Jama302(19), 2119-2126.
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