The U.S. Dietary Guidelines have always asserted that our nutritional needs should be met mainly via the foods we eat. The latest revision of the guidelines, though, say that supplements may be useful for providing nutrients you may not be getting enough of.
“As a nation, we are overfed and undernourished,” says Marci Clow, R.D.N., a dietitian at Rainbow Light, maker of food-based multivitamins and supplements. In a perfect world, our diets would be made up of nutrient-dense whole foods (fruits and vegetables, whole-grains, lean proteins, and healthy fats). But that’s just not the case: “Statistics show that about three-fourths of the population has an eating pattern that is low in vegetables, fruits, dairy and healthy sources of fat,” says Clow.
That said, it seems there’s a constant debate over whether or not we all need a daily multivitamin. While a daily multivitamin isn’t a magic bullet, there are plenty of situations in which we could all benefit from one.
If You Cut Out a Food Group
“Anyone who cuts out particular food groups or goes on a diet that cuts out certain foods—such as the Paleo Diet—may benefit from a multivitamin,” says sports dietitian Marie Spano, R.D., C.S.C.S. With Paleo, you might miss out on calcium and vitamin D, specifically, she explains. (Calcium is most commonly found in dairy, while vitamin D is often added to milk and cereal products—all no-no’s for Paleo.)
Another example: If you cut back on red meat, you may miss out on iron and vitamin B12, says Spano. (Iron helps transport oxygen throughout our bodies, while vitamin B12 supports energy production, according to the National Institutes of Health.) Many women in the U.S. are iron deficient, she adds—around 10 percent of white women and 20 percent of black and Hispanic women, says the American Academy of Family Physicians.
If You’re Pregnant
The surge of pregnancy hormones can cause nausea and lack of appetite—and adequate nutrient intake during pregnancy may become a challenge for many women, Clow says. “Consuming a varied diet should be the first and foremost way for providing nutrients during gestation; however, medical research shows that a prenatal multivitamin can play a critical role in supporting overall health for both mother and baby.”
While a regular multivitamin might be consumed to fill in dietary nutrient gaps, prenatal multivitamins are formulated to meet specific increased nutrient needs that accompany pregnancy, Clow explains. “Folic acid and iron are two of the most critical nutrients to fuel a healthy pregnancy—and are both recommended at nearly twice the level found in a standard multivitamin.”
If You Live in the North
In protecting yourself from the sun (hello, SPF) you might also be picking up a vitamin D deficiency, says Arielle Levitan, M.D., author of The Vitamin Solution. According to a study published in Nutrition Research, about 40 percent of the U.S. population could be deficient in the vitamin.
“Those with limited sun exposure, people living in northern latitudes, and people with darker skin tones should consider extra vitamin D,” says Clow.
If You’re a Big Exerciser
Research published in Nutrition Reviews suggests almost half of Americans do not get ample magnesium (which plays a role in over 300 biochemical reactions in your body) from their diets. Plus, magnesium is one of the minerals you lose when you sweat, says Levitan. That means fitness buffs who go hard and sweat hard, and endurance athletes who train for hours at a time, may be at greater risk for magnesium insufficiency.
As You Age
As we get older, we’re less able to absorb certain nutrients, says Clow. For example, B12 requires a substance called ‘intrinsic factor,’ which is secreted by stomach cells in order to be absorbed. Our production of this substance decreases as we age, she says. According to the National Institute on Aging, most people start to have trouble absorbing B12 around age 50.
Not to mention, conditions and circumstances often related to aging—like use of prescription medications, onset of degenerative diseases, and increased isolation—can also put the elderly at risk for vitamin and mineral deficiencies, says Clow.
As a rule of thumb, touch base with your doc before taking a multivitamin. A healthcare professional can make sure that medicines or supplements you already take won’t interfere with a daily multi, says Clow. (Common heartburn and diabetes medications, for example, can interfere with the absorption of magnesium and vitamins B12 and D, Levitan says.) And since everyone’s nutritional needs are different, consult with a doc or nutritionist for more info about which supplement may be best for you.