Nearly half of adults in the U.S. and 70% of older adults ages 71+ take a vitamin; about one-third of them use a comprehensive multivitamin pill. [1] But is this truly a necessity? There are certainly diseases caused by a lack of specific nutrients in the diet. Classic examples include scurvy (from a lack of vitamin C), beri-beri (vitamin B1), pellagra (vitamin B3), and rickets (vitamin D). But these conditions are rare in the U.S. and other developed countries where there is generally more access to a wide range of foods, some of which are fortified with vitamins. Individual vitamin supplementation may also be essential in certain cases, such as a deficiency caused by long-term poor nutrition or malabsorption caused by the body’s digestive system not functioning properly.

Who May be at Risk for a Nutrient Deficiency?

For those who eat a healthful diet, a multivitamin may have little benefit. A diet that includes plenty of fruits, vegetables, whole grains, good protein sources, and healthful fats should provide most of the nutrients needed for good health. But not everyone manages to eat a healthful diet. When it comes to specific vitamins and minerals, some Americans get less than adequate amounts, according to criteria set by the National Academy of Medicine. For example, more than 90% of Americans get less than the Estimated Average Requirement for vitamin D and vitamin E from food sources alone. [2]

Certain groups are at higher risk for a nutrient deficiency: in these groups supplementing with a multivitamin is recommended.

• Older age. The elderly are at risk for poor food intake for various reasons: difficulty chewing and swallowing food, experiencing unpleasant taste changes caused by multiple medications, or isolation and loneliness that can depress appetite. They also have trouble absorbing vitamin B12 from food. The National Academy of Medicine, in fact, recommends that people over the age of 50 eat foods fortified with vitamin B12 or take vitamin B12 pills that are better absorbed than from food sources. [3]
• Pregnancy. Getting enough folate, a B vitamin, is especially important for women who may become pregnant, since adequate folate can help lower the risk of having a baby with spina bifida or anencephaly. For the folate to be effective, it must be taken in the first few weeks of conception, often before a woman knows she is pregnant. Yet in the U.S., half of all pregnancies are unplanned. That’s why the Centers for Disease Control and Prevention recommend that all women of childbearing age (ages 15 to 45) consume 600 micrograms a day of folic acid. [3] This amount and other important nutrients for pregnancy—iron, calcium, vitamin D, and DHA—are available in a prenatal multivitamin.
• Malabsorption conditions. Any condition that interferes with normal digestion can increase the risk of poor absorption of one or several nutrients. Examples:
  • Diseases like celiac, ulcerative colitis, or cystic fibrosis.
  • Surgeries that remove parts of digestive organs such as having a gastric bypass for weight loss or a Whipple procedure that involves many digestive organs.
  • Illnesses that cause excess vomiting or diarrhea can prevent nutrients from being absorbed.
  • Alcoholism can prevent nutrients, including several B vitamins and vitamin C, from being absorbed.
• Certain medications. Some diuretics commonly prescribed to lower blood pressure can deplete the body’s stores of magnesium, potassium, and calcium. Proton pump inhibitors prescribed for acid reflux and heartburn can prevent the absorption of vitamin B12 and possibly calcium and magnesium. Levodopa and carbidopa prescribed for Parkinson’s disease can reduce the absorption of B vitamins including folate, B6, and B12.

Reasons to use a multivitamin:

• I am eating a limited diet or my appetite is poor so that I am eating less than usual.
• I am following a restricted diet for longer than one week. This could be prescribed such as a liquid diet after a surgical procedure, or a self-imposed diet such as on with the goal of weight loss.
• I have a condition that reduces my body’s ability to absorb nutrients (celiac disease, ulcerative colitis) or have undergone surgery that interferes with the normal absorption of nutrients (gastric bypass surgery, Whipple procedure).
• I temporarily have increased nutrient needs, such as being pregnant.
• I’m very busy and just can’t eat a balanced diet every day.