The World Health Organization estimates that approximately two billion people worldwide experience deficiencies in essential vitamins and minerals. These include vitamins A, C, D, and E, and minerals like choline, calcium, magnesium, iron, potassium, and fiber. A possible solution to deficiencies in vitamins and minerals are multivitamin supplements (MVMS), which aim to provide users customized dosages of the necessary vitamin or mineral that they are lacking. Most MVMS users are elderly people, with 70% of those aged 65 and older taking MVMS, resulting in an annual cost of nearly $12 billion (Hopkins Medicine). MVMS users are also normally health-conscious people who naturally consume a nutrient-rich diet, and this can lead to excessive nutrient intake (Blumberg et al., 2018). Though further research is needed to study the effects of vitamin and mineral supplements, recent studies have concluded that MVMS, as well as single vitamin supplements, do not prevent the development of chronic illness or improve long-term health, and can even negatively affect health in consumers.
Since vitamin supplements interact with gene expression at a biochemical level, this interaction is studied under an area called nutrigenetics which describes how nutrients affect gene expression (Blumberg et al., 2018). Pregnant women are encouraged to take folic acid supplementation because folate deficiencies may result in neural tube impairment, however, what is not told is that this supplementation can also interfere with DNA methylation and nucleotide synthesis. According to the review, “The Evolving Role of Multivitamin/Multimineral Supplement Use Among Adults in the Age of Personalized Medicine” (2018), consumption of folate may “play a role in pathogenesis of a number of health problems, including cardiovascular disease (CVD), cancer, and neurodegenerative conditions such as dementia and Alzheimer’s disease.” Other increased risks include the development of advanced colorectal lesions and prostate cancer.
Folic acid supplementation is only one example of how vitamin and mineral supplements can have deteriorating effects on the body. In the article, “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” (2013), studies found that beta-carotene, vitamin E, and vitamin A supplements actually “increase mortality.” This finding is supported by another article, “Is There Really Any Benefit in Multivitamins?” where studies confirmed that vitamin E and beta-carotene supplements are harmful, especially at high doses. These speculations are only preliminary, since there are a myriad of factors that impact metabolism, distribution, storage, utilization, and excretion of nutrients in the body. Such factors include age, sex, and environmental factors such as medication, pregnancy, disease, and smoking (Blumberg et al., 2018). These risk factors contribute to an informed decision when purchasing vitamin and mineral supplements, as there is a cost-benefit analysis that must be considered.
In a cohort of research that aims to link vitamin supplements to chronic diseases, there are many inconsistent results. In some observational studies, MVMS seem to reduce the risk of CVD myocardial infarction (heart attacks), but simultaneously increase the risk of cancer in male smokers. These studies also found no association between MVMS and the risk of CVD in postmenopausal women, but a link between MVMS use for 18 years and CVD-related deaths in women (Blumberg et al., 2018). The observational studies show the intricacies between vitamin supplement use and its interaction with metabolism in the context of chronic illnesses.
Randomized, controlled trials saw fewer inconsistencies, but the findings demonstrate the uselessness of vitamin supplementation. Evidence from these studies suggest that there is no overall reduced risk of cancer in MVMS users as compared to the placebo. MVMS had no impact on the risk of cardiovascular-related diseases, but in a group of only seventy subjects there was a significant decrease in the risk of myocardial-related death, which the article concluded was probably due to chance alone. These observations are supported by another research study done by Formann and his colleagues who wanted to review evidence to update the recommendations on taking vitamin supplements by healthy adults with no nutritional deficiencies posed by U.S. Preventative Service Task Force. In three trials where a randomized cohort agreed to take MVMS and 24 trials of single or paired vitamin consumption with nearly 400,000 participants, there was no evidence that vitamin supplements were beneficial in decreasing cancer, CVD, and mortality (Guallar et al., 2013).
Other findings in the randomized, controlled trials included a “nonsignificant 8% reduction in esophageal/cardiac cancer mortality,” and a “nonsignificant 38% reduction in cerebrovascular cancer mortality” (Blumberg et al., 2018). The final conclusions made within these studies were that there were no major safety risks with long-term use of MVMS as long as consumption did not exceed upper intake limit, as well as the fact that MVMS had no effect on mortality (Blumberg et al., 2018). Most importantly, the inconsistencies in some of these findings demonstrate the necessity for more clinical trials.
Dr. Larry Appel, the director of Johns Hopkins Welch Center for Prevention, Epidemiology, and Clinical Trials, and his team can confirm that MVMS have no concrete benefit to health. Researchers from Johns Hopkins concluded that MVMS “don’t reduce the risk for heart disease [and] cancer” which align with the conclusions aforementioned. Dr. Appel declares that “‘Pills are not a shortcut to better health and the prevention of chronic diseases.’” Instead, he reasons that the best way to prevent degenerative and chronic illnesses are to eat a healthy, balanced diet and maintain a healthy weight since supplements do not improve health.
- Blumberg, J., Bailey, R., Sesso, H., & Ulrich, C. (2018). The Evolving Role of Multivitamin/Multimineral Supplement Use among Adults in the Age of Personalized Nutrition. Nutrients, 10(2), 248. doi: 10.3390/nu10020248
- Is There Really Any Benefit to Multivitamins? (n.d.). Retrieved from https://www.hopkinsmedicine.org/health/wellness-and-prevention/is-there-really-any-benefit-to-multivitamins.
- Guallar, E., Stranges, S., Mulrow, C., Appel, L. J., & Miller, E. R. (2013). Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements. Annals of Internal Medicine, 159(12), 850–851. doi: 10.7326/0003-4819-159-12-201312170-00011