Ironically, "the people who are most likely to take vitamin supplements are the people who least need them," Mayne says. The affluent and health conscious are popping supplements faster than anyone. It may not be doing any good, and it could be harming them, she says. Anding concurs: "If you eat well, you probably don't need a multivitamin."
On the other hand, as Stampfer, who takes vitamin supplement himself, notes: "If I'm wrong, then I've wasted a few dollars. If I'm right, I've lowered my risk for some diseases I don't want to have."