Test Your Supplements Savvy

How much do you know about your vitamin pill?

By Kathleen Zelman, MPH, RD, LD>
WebMD Weight Loss Clinic - Feature

Reviewed By Cynthia Haines, MD

Should you or shouldn't you pop one, two, or 10 pills full of vitamins, minerals, and/or other hard-to-pronounce dietary additives?

The decision about whether to take dietary supplements -- and, if so, which ones to choose -- gets harder all the time. It seems like nearly every day brings a new study that adds to the confusion about the role of supplements in our health.

Once a Day

Though people with certain illnesses or conditions may need extra supplements, experts agree that nearly everyone can benefit from a once-daily multivitamin that includes minerals. Even the best eating plans can fall short of meeting all of the 40-plus nutrients we need each day.

"Most Americans fall short of meeting nutrient needs," says vitamin researcher and Tufts University nutrition professor Jeffrey Blumberg, PhD. "It is estimated that only 3% meet the new dietary guidelines, and clearly we can improve the overall nutrient composition of most diets with a simple, once-daily multivitamin/multi-mineral pill."

There's no need to spring for an expensive brand, says Katherine Tallmadge, RD, author of Diet Simple.

"A generic brand is just as good as the best-selling brands," advises Tallmadge, also a spokeswoman for the American Dietetic Association. "Compare label ingredients and look for multis that include up to 100% [of the Recommended Dietary Allowances] of most vitamins and minerals."

Too Much of a Good Thing

When it comes to vitamins and minerals, there is such a thing as too much of a good thing. Dietitians have long warned of the dangers of excess vitamins and minerals, especially the fat-soluble types (vitamins A, D, E and K) ones that are not easily eliminated from the body.

"Individuals who start the day with a vitamin drink, eat energy bars throughout the day along with fortified foods, and [take] a cocktail of individual supplements risk developing serious vitamin or mineral toxicities," warns Tallmadge.

While illnesses resulting from mega-does of vitamins and minerals are rare, it's better to be safe than sorry, Tallmadge says. "The scientific research is lacking on the long-term safety of large doses of supplements," she warns.

Taking a daily multivitamin, on the other hand, won't put you at risk of overdoing it, says Blumberg. "The risk of dietary deficiencies is far greater than the risk of overdosing on vitamin and mineral supplements," he says.

Food First

Experts say it's important to keep in mind that supplements are intended to enhance, not take the place of, a healthy diet. That's because food offers so much more than vitamins and minerals.

"It is safer to get nutrients from foods than supplements because of the disease-fighting, interactive compounds; fiber; and phytochemicals that occur in food and do not exist in a pill," says Tallmadge.

New health benefits from various substances found in food are being discovered all the time. For example, in a just-published study in the American Journal of Clinical Nutrition, researchers found that antioxidants found in certain brightly colored fruits and vegetables may offer protection against arthritis.

Test Your Supplement IQ

Take this quiz to test your supplement knowledge.

1. Which of the following conditions calls for taking a vitamin and/or mineral supplement?

a. Pregnancy
b. Nursing
c. Smoking
d. Dieting
e. Having a chronic disease
f. Eating a vegetarian diet

Answer: All of the conditions warrant taking a supplement.

For pregnant or nursing women, a prenatal vitamin ensures adequate nutrients for the developing fetus or nursing baby. Folic acid is very important, both before and during pregnancy, to prevent birth defects.

Smokers need extra vitamin C. This requirement can be satisfied by a supplement, or by eating more vitamin C-rich foods like citrus fruits, red peppers, strawberries, broccoli, and tomatoes.

Dieters can fall short of meeting their nutritional needs if they choose the wrong foods. The best strategy is to eat at least three meals a day and choose nutrient-rich foods like fruits, vegetables, whole grains, and low-fat dairy. To fill in the nutritional gaps, a daily multivitamin is the smartest approach.

If you have a chronic disease, a multivitamin is usually a safe bet. Check with your doctor to be sure that all your nutritional needs are being met.

If you're a vegetarian, your particular diet determines what supplements you may need. Vegans, who eat no animal products, should pay special attention to protein, iron, zinc, calcium, riboflavin, vitamins D, B-12, and A, and iodine. According to an American Dietetic Association position paper, a well-planned eating plan -- which may include supplements -- can meet your requirements for these nutrients. Seek the services of a registered dietitian to ensure your vegetarian diet is adequate.