Multivitamins: How to Pick the Right Supplement

1 Pill, 5 Reasons to Pop It

A multi may make you less hungry when you're dieting, reveals a new Canadian study. Researchers think that it short-circuits the body's natural response to calorie cutting, which is to boost appetite to counter vitamin deficiencies.

A good vitamin prevents low iron, which makes you drag during workouts and may also cause hair loss, according to a French study. One in 10 women is low in iron, with vegetarians, vegans, endurance athletes, and anyone with heavy periods being especially vulnerable.

The ingredients in a multi have been linked to a lower heart disease risk. But it's an aid to -- not a substitute for -- fruits and veggies, which may deliver other disease-fighting compounds.

Taking a multi may cancel out the breast cancer risk incurred by drinking alcohol. In a recent study from Boston's Brigham and Women's Hospital, women who had a daily cocktail and took a multi had a lower risk than those who didn't pop the pill. The supplement may correct alcohol-triggered deficits of B vitamins that encourage tumor development.

Multi users have a 41 percent lower risk of ovulatory infertility, finds a Harvard School of Public Health study. Folic acid and other B vitamins appear to help promote healthy ovulation.