This question is very popular among athletes and active people in these modern times so let’s try to answer it!  

What Are Multivitamins?

Vitamins are essential organic compounds that your body needs to work optimally, be it your metabolism, nervous system, or cell health. Fat-soluble vitamins include vitamins A, D, E & K and the body stores fat-soluble vitamins in various tissues. Water-soluble vitamins consist of the B-vitamins and vitamin C.

Minerals are simpler elements, but are as important as vitamins for your body to function. Minerals serve as structure for tissue, important components of enzymes and hormones, and regulators of metabolic and neural control. Multivitamins usually contain both vitamins and minerals (both belong to the micronutrients group).  

Are Multivitamins Good or Bad for You?

The answer to this question is maybe. Studies show no positive effects of multivitamin supplementation on regular, well-nourished individuals (2). If you have suboptimal levels of vitamins and minerals in the body, it can be safely stated that supplementation has many benefits. It should be pointed out that we don’t know the optimal level of most vitamins, only which levels that are too low.

Unless there is a specific medical reason, studies do not suggest multivitamin supplementation for primary prevention of chronic diseases because of evidence that they are not effective. (2) However, many people want to take vitamins based on their own belief systems, and studies suggest that clinicians not struggle against that practice as long as it is harmless.(5) Other experts disagree and would recommend more strongly against such supplements because the risk of overdose. Doctors recommend the use of multivitamins to those who have a medical reason.Future studies will give us more and more knowledge about if multivitamin supplementation has a good or a bad effect on human health in the long-term.

Are Multivitamins Safe?

Just like any other meds, multivitamins can also be bad for your health if the dosage is way above the Recommended Dietary Allowance (RDA). Potentially toxic levels of individual vitamins can be achieved easily in people who take very high-potency vitamins, which can be obtained in specialty stores, over the internet, and even in pharmacies. High doses can also be achieved by taking a large number of pills even if the dose per pill is not high. The Institute of Medicine (IOM) and the Office of Dietary Supplements has suggested Tolerable Upper Intake Levels for specific vitamins, which is the highest daily dose that is unlikely to cause adverse health effects in the general population (5, 10). To summarize these recommendations, we can say that for most healthy people aged above 19 years old, you should stay below the following maximum doses of vitamins:

• Vitamin A (preformed): 3000 mcg (9900 IU)
• Vitamin C: 2000 mg
• Vitamin D 100 mcg (4000 IU)
• Vitamin E (Alpha-Tocopherol) 1000 mg
• Vitamin B3 (Niacin) 35 mg
• Vitamin B6 (Pryoxin): 100 mg
• Vitamin B9 (Folate) 1000 mcg

Water soluble vitamins (folate, vitamin C, B vitamins) can generally be tolerated at high doses, with toxicity occurring only at doses thousands of times the RDA. A possible exception is the risk of kidney stones, which may be increased after doses of vitamin C that are 10 to 25 times the RDA. (5)

Fat Soluble Vitamins

Fat soluble vitamins (vitamins A, D, E, and K) are generally more toxic than water soluble vitamins. Vitamin D may cause high calcium levels at doses equal to 4000 units/day (recommended upper limit) in some people. Vitamin A in pregnancy can cause deformities the growing child even at lower doses. (5)

Vitamins in high doses aren’t always better. Something that “seems” healthier, like antioxidants, might actually do HARM. Antioxidants are by many believed to be cancer-protecting. In one large study,people at risk of cancer (smokers and asbestos-exposed). were given vitamin E and beta-carotene supplements. Eight years later, it turned out that the beta-carotene group had an INCREASED risk of developing cancer! (6) Thus there are also concerns that vitamin E supplementation above 400 units per day may be associated with increased all-cause mortality. (5) . So remember, more is not always better when it comes to vitamins! (6)

Who Needs Multivitamins?

Only certain people. In most cases, a balanced diet with fruits and vegetables promotes health not only by providing known vitamins, but also because it contains fibre and thousands of other less well-defined micronutrients and replaces meat and animal fat. However, people on restricted or special diets may have additional needs for vitamin supplementation. As an example, vitamin B12 levels are strongly affected by dietary intake and its absorption in the digestive tract. In younger adults, low consumption of animal-source food is the main cause of low vitamin B12 levels; in older adults, bad absorption due to an aging gut system of vitamin B12 from food is the most common cause. The lowest intakes of vitamin B12 are seen in those who eat no animal products, and vitamin B12 intake increases with increasing intake of animal source foods.

People who may need to supplement with vitamins include:

• Semi-vegetarians
• Lacto-ovo vegetarians
• Lacto-vegetarians
• Vegans
• Macrobiotic dieters (the “yin-yang” diet)

People who consume a vegan diet should supplement with vitamin B12 (at the RDA of 2.4 micrograms/day) if they do not consume other fortified food products (such as cereals). They are also at risk for too low vitamin D levels and should consider a supplement, particularly during winter months. However, low vitamin D levels are an issue for most people, regardless of diet. (5)

Lacto-ovo vegetarians and lacto vegetarians should also consider supplementation with vitamin B12.

Multivitamin supplementation should be considered in people at risk for vitamin deficiency, such as those with alcoholism, bad intestinal absorption, a vegan diet or some inborn errors of metabolism, as well as those being treated with haemodialysis or nutrition through an I.V. In addition, in persons with a specific vitamin deficiency, a multivitamin may be a reasonable choice over supplementation with individual vitamins if a multivitamin is less costly and the formulation contains an appropriate dose.

Are Multivitamins Necessary?

Maybe you heard someone say: “You have to supplement your diet with multivitamins in order to live healthy or gain muscle!”  Tough a healthy individual with a normal diet that doesn’t exercise probably won’t need multivitamins, check the special diets above, the best way to see if they are necessary is to get yourself tested and have a discussion with your doctor about this. Some people might have a vitamin deficiency and might not know by the time the symptoms and signs appear, these are the people who will need supplementation of vitamins. Not only does this need to be confirmed by a doctor but it has to be very carefully monitored in order to take the right dosage and to stop the use of the supplementation if it’s possible. This is classic with B12 deficiency, which takes years to cause symptoms.

For athletic populations, few studies have reported enhancing value of vitamins and minerals in well-nourished individuals. Alternatively, if an athlete is deficient in a vitamin, supplementation or diet modifications to improve vitamin status can consistently improve health and performance. (1)

Can Multivitamins Help Muscle Growth?

Regarding muscle growth, multivitamin supplementation didn’t prove a significant muscle growth effect or greater strength. (1) However there are some studies that show different effects of some vitamins. Some vitamins can help an athlete tolerate training to a greater degree by reducing oxidative damage       (vitamin C and E) and maintain a healthy immune system. Vitamin D supplementation failed to report ergogenic impact in athletes, whilst in general populations have been linked to improved muscle health and strength. (1) Vitamin K improved the balance between bone formation and resorption. B6 vitamin combined with vitamins B1 and B12 may increase serotonin levels and improve fine motor skills that may be necessary in sports like pistol shooting and archery. (1) There are unclear effects of how beta-carotene may help athletes tolerate greater training. (1) Although calcium supplementation showed no ergogenic effects it is proven to promote fat metabolism and help manage body composition. (1) Zinc supplementation minimized training induced changes in immune function. (1)

Research is Scarce

The studies mentioned above are, however, a minority. Most studies investigating vitamins and minerals don’t find any improvements for muscle growth or athletic performance. No positive effects of vitamin supplements are proven regarding muscle growth so you don’t have to take them if you plan to work out. However, correcting vitamin D deficiency may improve athletic performance for some athletes and protect against injury. Seeing how most people are deficient in vitamin D, supplementing with it might not be a bad idea (7). It has also been shown that athletes taking 5000 IU (125 μg per day) together with 50-100 μg of vitamin K1 and K2 recover better and are able to train more frequently. (8)

Can Multivitamins Help Acne?

Few studies were made on this subject but some of them state that drug-induced acne is regulated by vitamin A and vitamin D, however it can be triggered by vitamin B2, B6 and B12. Certain treatments for acne are considered topical retinoid (vitamin A derivate) and their effects contribute to the normalization of follicular keratinization and decreased cohesiveness of keratinocytes, resulting in reduced follicular occlusion and microcomedone (early acne) formation.

The vitamin A derivate cream is called adapalene and is an effective acne treatment, but takes 8-12 several weeks of daily use before effects are seen, so most people fail to see results because they aren’t able to stick to the treatment for so long. There is also a vitamin A derivate called isotretinoin (Accutane) and can be very effective but it has many potential side effects, which is why your doctor should oversee the treatment.

Effective Treatments for Acne

Other effective acne treatments are bensoylperoxide, azelaic acid, tretinoin, anti-contraceptive pills for women, or a short sourse of antibiotics to prevent scarring. The latter only has temporary effect, and promotes superbug development so antibiotics should be avoided and if used only used for 3-6 months.

You may have heard that vitamin B5 or light therapy can help against acne, but there is no scientific evidence behind these treatments. (9)

If you have acne, contact your doctor!

Summary: What Multivitamins Should I Take?

Finally we arrive at the most important part, what multivitamin should you take? In summary:

• Take no multivitamins if you eat well and live a healthy, balanced life.
• If you think you need extra vitamins, consult your doctor to get tested.
• If you have a special diet (those mentioned above), read more about it and check if you are at risk of any deficiencies, and supplement accordingly.
• Consult your doctor before taking multivitamins. You might need a specific vitamin depending on the advice your doctor gives you.

In conclusion, multivitamin supplementation shouldn’t be taken unless there are suboptimal levels of vitamins in the body. Multivitamins don’t seem to improve muscle growth or strength. A well-balanced diet and caloric surplus is still the best way to gain muscle. No quick fix available (apart from steroids, sorry)! Keep in mind that multivitamins can be toxic so think twice before you take them!

Article written by Vlad George Rãdulescu

Edited by Artin Entezarjou, M.D