Taking a gender-specific vitamin makes sense. Women's formulas often have extra calcium, folic acid, and iron. And while basic multis contain iron, which women need, men tend to get enough through food. Extra iron can be dangerous for males if they have hemochromatosis, a condition that can damage the liver and heart. So men might be better with a men-specific formula. Otherwise, these special multis are mostly marketing, says Tod Cooperman, M.D., president of ConsumerLab.com, which evaluates health products. When pills pack extra ingredients, such as lutein for eye health, it's hard to know whether the amount is enough to make any real difference.