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Vitamins and Minerals
There are many different vitamins and minerals, which can be found in almost all foods. Each vitamin and mineral has a different function in the body. Vitamins help support the immune system, convert macronutrients (carbohydrates, proteins, and fats) into energy, and regulate the nervous system. On the other hand, minerals help support structural and regulatory functions such as fluid balance, muscle contractions, tissue growth, and so on. Both are incredibly important.
For each type of vitamin or mineral, you can find dozens to hundreds of studies on its effects on different bodily functions under various conditions. For example, the effect of vitamin D on muscle strength and fat mass was recently described in two separate articles, which consulted almost 40 studies. In this brief article on multivitamins, I will keep it more general.
Do You Need a Multivitamin?
Using a multivitamin is a bit like receiving a filled toolbox as a mechanic. There will be tools in it that you just needed, but also tools that the workshop is already full of and only cause clutter. Moreover, it may turn out that even the items you needed are still insufficient in that box. In other words, it’s not exactly tailored.
When the basic diet is in order, you usually get enough vitamins and minerals. The use of additional dietary supplements is often not necessary. For people with a vitamin deficiency, reduced absorption, or perhaps a modified diet, it may be advisable.
Furthermore, the likelihood of a deficiency can vary greatly depending on the vitamin and mineral, and despite a varied diet, you may still have a deficiency or excess of something somewhere. For example, you mainly get vitamin D from sunlight, and the deficiency of vitamin D in the cold months cannot be compensated for by food alone because vitamin D is only present in small amounts in some types of food.
In addition, there is a considerable difference between the minimum levels at which a deficiency occurs and the ideal levels at which you benefit optimally from certain micronutrients, as vitamins and minerals are also called. Supplementation then provides supportive action for the body.
Exercise and the Need for Vitamins and Minerals
People who exercise regularly have an increased need for certain vitamins and minerals. This is mainly due to the fact that these are lost through sweating. It also has to do with the fact that the stress level, the physical stress in active people, is different from that in non-exercising people. From this, you can infer that the use of a multivitamin is desirable for active people.
However, there is also a turning point. Active people have an increased need for energy and therefore generally consume more food. The increased need for vitamins and minerals may already be compensated for by this.
Dangers of Vitamin and Mineral Overdose
Although vitamins and minerals certainly interact with the immune system, they can only provide a boost when there are actual deficiencies in the body compared to ideal values. A deficiency of vitamins and minerals compared to the required minimum can severely affect your immune system. With a good diet, a supplement is often not necessary and may even have disadvantages.
An excess of vitamins and minerals can severely disrupt the balance in the body. There are even certain substances that can cause serious damage to the body. For example, an excess of vitamin B6 is associated with muscle and nerve damage, and iron supplementation can lead to gastrointestinal complaints. In addition, certain vitamins can inhibit the absorption of other nutrients. A mega-dose of vitamin C, for example, could inhibit the absorption of copper in guinea pigs [2], but this has not been demonstrated in two studies involving humans [3,4]. High-dose multivitamins are therefore not always good to use indiscriminately.
Especially with vitamins that are stored in fatty tissue, the so-called fat-soluble vitamins (vitamins A, D, E, and K), you should be careful with high doses. These are difficult to excrete from the body, although this danger seems limited in the case of vitamin D.
It is also a myth that water-soluble vitamins cannot cause harm if overdosed. An excess of certain vitamins would indeed be excreted in urine. That is largely true, but be careful. An extremely high dose of, for example, vitamin C can also lead to kidney damage.
Absorption in the Body
There are natural and unnatural substances processed in a multivitamin. It sounds logical that the natural variant is always better absorbed, but that is not always the case. Certain forms of natural vitamins/minerals are not durable and therefore not suitable for making a supplement.
In addition, the natural form of a substance is not always well absorbed from a supplement. In that case, it is chosen to add an inorganic/chemical compound to the supplement that retains its quality.
So Should You Use a Multivitamin or Not?
You can perfectly use a supportive multivitamin when your basic diet is unbalanced. Try to choose a supplement where the normal recommended daily amounts (RDA) of vitamins and minerals do not far exceed. Choose, for example, where all substances are around 100% of the RDA. This must be stated on the label. However, the Vitamin Information Bureau recommends a multivitamin with 100 to 300% of the RDA [5].
Even wiser is to specifically (have) investigate(d) which vitamins and minerals you need more of. If it has been demonstrated, for example, through blood tests, that you have deficiencies in certain substances, you can opt for a higher-dose and specific supplement. Consider this choice carefully and consult a (sports) dietitian or (family) doctor if necessary.
Last but not least: Do not see a supplement as a replacement for basic nutrition. Basic nutrition contains much more than just vitamins and minerals!
References
- Van Rossum, C.T.M. & et al, 2011. Dutch National Food Consumption Survey 2007-2010
- Milne DB, Omaye ST. Effect of vitamin C on copper and iron metabolism in the guinea pig. Int J Vitam Nutr Res. 1980;50(3):301-308.
- Finley EB, Cerklewski FL. Influence of ascorbic acid supplementation on copper status in young adult men. Am J Clin Nutr. 1983;37(4):553-556. (PubMed)
- Jacob RA, Skala JH, Omaye ST, Turnlund JR. Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. J Nutr. 1987;117(12):2109-2115. (PubMed)
- Vitamine-info.nl/nieuwsartikel/article/de-belangrijkste-fabels-en-feiten-over-multivitamines-182/#.VFuIvGddU1I
