Vitamins. We’ve all heard about them. Whether it be a chiding mom telling her child to eat their vegetables or a bodybuilder explaining the supplements they take, vitamins continually pop up in our daily lives, and more often than not, they’re perceived as essential for a healthy life. But, what exactly are vitamins, and do we really need them?
In the most basic terms, “vitamins are a group of substances that are needed for normal cell function, growth, and development.” Unfortunately, human beings cannot make sufficient amounts of these important vitamins within their own bodies, so these nutrients usually have to be obtained externally. If this does not happen and the body is deprived of vitamins, a variety of health problems arise, from minor issues such as headaches to severe issues like increased risks of heart disease and cancer. On the surface, it appears that vitamins are completely beneficial, and one might even be inspired to take the well-advertised multivitamin supplement in their daily diet. Seems straight-forward, right? Vitamins potentially reduce our risk of heart disease and cancer, so everyone should eat a lot more of them. Case closed. As it turns out, it’s not quite that simple.
While vitamins do indeed play a critical role in maintaining an individual’s well-being, there are a surprising amount of dangerous vitamin overdoses that are reported each year. In 2017 alone, the American Association of Poison Control centers reported around 60,000 cases of harmful vitamin exposures, with around 46,000 of those cases pertaining to children under the age of 5. How can these substances—which our bodies so desperately need to function properly—find their way onto Poison Control’s “most frequent exposures” list?
First off, let’s broadly differentiate between the two types of vitamins that can lead to overdoses: water-soluble and fat-soluble. The former lives up to its name—water-soluble vitamins (B and C) can dissolve in water, and so as long as one stays hydrated, the body can filter out these vitamins. Therefore, very rarely are there incidents of vitamin B or C overdose, as any excess of these two vitamins is simply excreted. The same cannot be said for fat-soluble vitamins, such as vitamins A, D, E, and K, which are dissolved and stored in excess within the body’s fat, making them much trickier to get rid of. In addition to the difficulty of removing these fat-soluble vitamins, the body only needs very small amounts on a daily basis. For example, whereas the National Institutes of Health recommends that the average child gets around 30 mg of Vitamin C (water-soluble), it recommends that the average child only intakes around 15 μg of Vitamin D (fat-soluble), which is a difference of more than 1000 times less. In proper dosages, both water-soluble and fat-soluble vitamins are absolutely beneficial and necessary for humans. However, when considering the miniscule size of these recommended dosages, it isn’t difficult to see why vitamin overdoses can happen quite easily.
Another major factor that fuels vitamin overdose is the vast amount of societal misconception about vitamins. Many of these misconceptions pertain to supplementation, rather than the vitamins that many of us already receive in our diets. In fact, vitamins have been used synonymously with supplements so frequently in North America that the Oxford dictionary defines vitamins as “pill[s] containing a specified amount of a particular vitamin or vitamins taken as a dietary supplement.” One common and dangerous myth that arises with supplementation is that taking more vitamin supplements makes a person increasingly healthier. As has been shown through vitamin overdose, this is simply not the case. In 2003, the U.S. Preventive Services Task Force conducted a study to “systematically review evidence for the benefit and harms of vitamin and mineral supplements in community-dwelling, nutrient-sufficient adults for the primary prevention of cardiovascular disease and cancer.” As a result, the task force “concluded that there was insufficient evidence to recommend for or against the use of vitamins A, C, and E [and] multivitamins...for the prevention of cardiovascular disease or cancer.'' The study found no proof of any extra benefit from multivitamins or supplements to a healthy individual’s wellbeing. One could logically argue that the subjects in question already had sufficient nutrients within their diets, which leads to another common myth with dangerous repercussions—that vitamin deficiencies are common within our society. Although certain diets of certain regions around the world may lack the proper nutrients, the CDC found in a nationwide biochemical assessment that, on average, less than 10% of the population actually suffers from a vitamin deficiency. In actuality, it is quite rare for an individual to be so deprived of vitamins that they reach a state of deficiency.
Despite all of these studies, the population continues to fuel the supplement/multivitamin industry. The Annals of Internal Medicine estimated that United States consumers spent about $28 billion dollars on vitamin supplements in 2010 alone. And that’s not all. Since vitamins are readily accessible as over-the-counter supplements in thousands of stores, a common consumer can potentially purchase and accidentally overuse vitamins without ever having consulted a physician. That, coupled with the common myths around vitamin use, creates dangerous circumstances that increase the likelihood for vitamin overdose. As Dr. Cohen concisely explains in “The Supplement Paradox”, about $250-300 million dollars per year were spent by the National Institutes of Health from 1999 through 2012 to investigate the health effects of additional vitamin supplements. He concluded that “many major clinical studies were published, but...generally failed to demonstrate beneficial effects on health.”
To summarize what we’ve seen thus far, there is little to no benefit to supplementation. Meanwhile, there are numerous, adverse effects that can result from vitamin overdose; Symptoms may include anything from minor irritations of the eye to seizures to severe intestinal bleeding. Additionally, as discussed earlier, there is a very low percentage of the population that actually battles with the opposite fear: vitamin deficiency. If this is the case, then why take the risk?
Vitamins are critical for our well-being; without them, we would not be able to continue living happy and healthy lives. However, unless specifically prescribed by a doctor, there really isn’t a need to take extra supplements. The potential consequences far outweigh the benefits. So the next time you hear someone talking about how healthy they are for taking “300%” of their daily value of vitamin D, be skeptical. Stay informed and, most importantly, stay healthy.