To ensure that you’re getting all the vitamins and minerals necessary for good health, consider taking a daily multivitamin. Choose a multi with iron if you’re a woman who is still menstruating. All men, and women who have stopped menstruating, should use a formulation without iron. There is no need to take megadoses — about 100 percent DV of most vitamins and minerals is sufficient. The one exception is vitamin D — look for formulas with at least 400 IU (100% DV), preferably 800 to 1000 IU.