Unless you eat a perfectly balanced diet and soak up plenty of sunshine, you might need a diet supplement. But before dropping dough on a bottle of pills, it's best to determine if you really need them by checking with a doctor. Here's what science has to say about some of the most common supplements.
Cost: $7 for 75
Claim: Makes up for nutritional inadequacies and improves overall health.
What experts say: In people with very poor nutrition, multivitamins can reduce the risk of certain cancers, but there really isn't any evidence that multivitamins prevent chronic disease. Although they are not necessary for most people, multivitamins can help cover nutritional deficits, they're relatively inexpensive, and they cast a pretty broad and basic net.
Cost: $11 for 100
Claim: Helps with certain types of anemia and reduces the risk of heart disease.
What experts say: B12 has been shown to lower homocysteine levels in certain populations (people with heart disease often have high homocysteine levels), but there is a lack of evidence that it actually helps prevent heart disease. Supplements are recommended for those who are B12 anemic.