By Ana Serban, Fall 2023.

For many people, taking a vitamin before heading out the door is a regular part of their morning routine. Many of those people taking them do not know a lot about them apart that they are supposed to increase the levels of the vitamin they are lacking. 

Vitamins in the natural world are the substances found in food and absorbed during digestion. They are either water-soluble or fat-soluble. [1] Water-soluble vitamins must be dissolved in water before being absorbed by the body and are often released through urine. They are usually found in plant products. As plants are more common than animals, this makes water-soluble vitamins the most abundant type of vitamins. Fat-soluble vitamins dissolve in fat and accumulate in the body. They are absorbed from consuming animal products. [2]

Apart from satiating the appetite, vitamins improve many of the body’s systems such as the immune system, circulatory system, endocrine system, and more. Thus, they are necessary for human survival. [1] Although they are mainly absorbed through foods, people often have deficiencies due to imbalanced diets, lifestyle choices, and medical conditions. Pharmacies have introduced vitamin supplements that are meant to supplement those deficiencies. For example, vegans may need to take supplements containing fat-soluble vitamins as they are mainly found in animal products. In fact, supplements have even become prescriptions. For instance, pregnant women are often prescribed vitamin supplements containing maternal folic acid to help with the production of healthy cells in their unborn offspring. [3]

Supplements are meant to imitate the natural vitamins. Whether the vitamins are extracted from natural sources, like plants or animals, or synthetically produced in a laboratory, the structures of vitamins are generally the same. When prepared, the powdered chemicals go through a wet granulation stage before being encapsulated. These capsules are packaged and distributed to stores. [4]

Most supplements have begun being advertised as a way to prevent health issues such as cardiovascular disease or cancer to people who are otherwise healthy. In fact, most people who take vitamin supplements are people who live a healthy life. This has sparked many research projects to determine their success in improving health.

A journal published by other researchers at the University of Pennsylvania [5] reported that any effect by vitamin supplements is extremely small. Despite being able to increase the levels of the vitamin in the organism, they do not help with improving the bodily function they claim to help. In fact, the researchers found that some supplements, specifically those extracted from natural products, can be harmful. A study [6] found that calcium supplements with an intake of more than 1000 milligrams per day increases the risk of all-cause mortality in men. It is unsure where the harm comes from. Although it may be proposed that it comes from an excess of the vitamin, there is a lack of evidence showing the long-term effects of vitamin excess. 

Similarly, researchers at Harvard University [7] found correlations between health and vitamin supplements for certain body systems, while nothing for others. For instance, men who took multivitamins were 8% less likely to develop cancer. On the other hand, there were no improvements seen in the brain’s functions, such as memory or mental skills. [7]

The little to null correlation is a common pattern in the results of these studies. [8] However, the way each experiment was conducted affects the results they received. An example of this is a series of experiments testing to see the effectiveness of vitamin D supplements in preventing different health issues. In the VITAL experiments (Vitamin D and Omega-3 Trials) [6] , vitamin D was not found to have a correlation with preventing cardiovascular diseases or cancer, both tested separately on different groups of older adults. However, a separate study [6] found calcium supplements mixed with vitamin D were effective in decreasing the risk of hip fracture in the elderly, unlike taking only calcium supplements which were found to be ineffective. 

It is to note that each of these experiments were conducted on different populations with different controls, manipulations, and assignments. [8] Many were experimented on older men of different socioeconomic backgrounds. Most of the people who consume vitamin supplements are older women of healthy, wealthy, and educated backgrounds. [6] Thus, the experiments do not necessarily reflect the societal consumption of vitamin supplements. Additionally, it would be helpful to see the effects in groups where people have similar vitamin deficiencies to see if their health improves. 

Overall, the inconsistent results of these experiments make it difficult to conclude whether taking vitamin supplements as a way to prevent diseases is a healthy choice. Many physicians still claim that supplements are a good way to make up for any deficiencies if necessary. Otherwise, it is best to stick to getting daily doses of vitamins from food alone. 

 

[1] “Vitamins and Minerals.” The Nutrition Source, March 8, 2023. https://www.hsph.harvard.edu/nutritionsource/vitamins/.

[2] BSc, Atli Arnarson. “The Fat-Soluble Vitamins.” Healthline, January 11, 2022. https://www.healthline.com/nutrition/fat-soluble-vitamins.

[3] “Vitamins and Other Nutrients during Pregnancy.” March of Dimes, September 2020. https://www.marchofdimes.org/find-support/topics/pregnancy/vitamins-and-other-nutrients-during-pregnancy#:~:text=Take%20a%20prenatal%20vitamin%20every,all%20necessary%20nutrients%20from%20you.

[4] Quinones, Roberto. “How Are Vitamins and Supplements Made?” BodyLogicMD, January 2, 2020. https://www.bodylogicmd.com/blog/how-are-vitamins-and-supplements-made/#:~:text=As%20mentioned%20above%2C%20supplements%20can,organic%20compound%20(like%20acetone).

[5] “The Truth About Supplements: 5 Things You Should Know.” Pennmedicine.org, March 31, 2022. https://www.pennmedicine.org/updates/blogs/health-and-wellness/2020/february/the-truth-about-supplements.

[6] Zhang, Fang Fang, Susan I Barr, Helene McNulty, Duo Li, and Jeffrey B Blumberg. “Health Effects of Vitamin and Mineral Supplements.” BMJ, 2020, m2511. https://doi.org/10.1136/bmj.m2511. 

[7] “Do Multivitamins Make You Healthier?” Harvard Health, April 7, 2022. https://www.health.harvard.edu/mens-health/do-multivitamins-make-you-healthier.

[8] Guallar, Eliseo, Saverio Stranges, Cynthia Mulrow, Lawrence J. Appel, and Edgar R. Miller. “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements.” Annals of Internal Medicine 159, no. 12 (2013): 850–51. https://doi.org/10.7326/0003-4819-159-12-201312170-00011.