Everything You Need to Know About Multivitamins

Rebecca Oshiro, MS, CN, Arivale Coach
Rebecca Oshiro
MS, CN, Arivale Coach

Research shows approximately one-third of Americans take a multivitamin every day1. So, it’s not surprising that, as a nutritionist, I’m frequently approached by people wondering if they should take a multivitamin.

While, for the average person, taking a multivitamin every day is unlikely to reduce their risk of cancer, heart disease, or death in general2,3, most people take multivitamins as a type of “health insurance” – a way to make sure they’re meeting all their nutritional needs and because they believe it will help them be healthier.

Why take a multivitamin?

While there isn’t solid evidence for multivitamins making you all-around healthier, there are certain circumstances when a person may benefit from a well-formulated multivitamin. For example:

  • The CDC recommends all women of reproductive age supplement their diet with 400 mcg of folic acid every day to reduce the risk of birth defects4.
  • It’s advisable that people over the age of 50 – 30 percent of whom have a reduced ability to absorb B12 – meet their B12 needs by consuming fortified foods, or with a well-formulated supplement.
  • B12 is also a concern for strict vegans, who don’t consume any foods with an absorbable form of the vitamin. They should supplement accordingly5.
  • Finally, individuals following restricted diets, such as low carb, ketogenic, or gluten free, frequently don’t consume enough vitamins and minerals because fruits, vegetables, and whole grains are the best sources of these nutrients6,7.

Let’s stop here to note that many people could take a standalone supplement based on their specific need and be equally as well off as they would be with a multivitamin. However, multivitamins are an easy and general approach to dealing with a potential insufficiency. And, in the case of people following restricted diets, a multivitamin would be the best approach as they tend to be low in multiple vitamins and minerals.

How to choose a multivitamin:

When choosing a multivitamin, look for one that’s lower in potency and in general doesn’t provide more than 300 percent of a given nutrient. Some research has found that taking high doses of certain vitamins and minerals over the long term may be unsafe – something on which Arivale has previously reported.

Something else to keep in mind: you’re still going to get nutrients from your regular diet on top of whatever multivitamin you choose. In some instances, a combination of whole foods, fortified foods, and supplements can cause you to take in more of certain nutrients than is safe for the long term8.

Furthermore, some forms of vitamins and minerals are better absorbed and used by the body than others, and it’s desirable to choose a formula that includes these more-usable forms.

Due to the complexity of this topic, it’s advisable to work with a licensed expert, such as a Certified Nutritionist or Registered Dietitian, to determine whether a multivitamin is appropriate for your unique body and nutritional needs.



  1. Bailey RL, Gahche JJ, Lentino CV, et al. “Dietary supplement use in the United States, 2003-2006.” J Nutr. 2011;141(2):261-6.
  2. Neuhouser ML, Wassertheil-smoller S, Thomson C, et al. “Multivitamin use and risk of cancer and cardiovascular disease in the Women’s Health Initiative cohorts.”Arch Intern Med. 2009;169(3):294-304.
  3. Park SY, Murphy SP, Wilkens LR, Henderson BE, Kolonel LN. “Multivitamin use and the risk of mortality and cancer incidence: the multiethnic cohort study.” Am J Epidemiol. 2011;173(8):906-14.
  4. Folic Acid. https://www.cdc.gov/ncbddd/folicacid/about.html. Accessed February 26, 2019.
  5. Otten JJ, Hellwig JP, Meyers LD (editors). “Dietary Reference Intakes: The Essential Guide to Nutrient Requirements.” Washington, DC: The National Academies Press. 2006.
  6. Vici G, Belli L, Biondi M, Polzonetti V. “Gluten free diet and nutrient deficiencies: A review.” Clin Nutr. 2016;35(6):1236-1241.
  7. Christodoulides SS, Neal EG, Fitzsimmons G, Chaffe HM, Jeanes YM, Aitkenhead H, Cross JH. (2012). “The effect of the classical and medium chain triglyceride ketogenic diet on vitamin and mineral levels.” Journal of Human Nutrition and Dietetics. 2012 Feb; 25(1):16-26. doi: 10.1111/j.1365-277X.2011.01172.x.
  8. Mulholland CA, Benford DJ. “What is known about the safety of multivitamin-multimineral supplements for the generally healthy population? Theoretical basis for harm.” Am J Clin Nutr. 2007;85(1):318S-322S.