But what if, like most Americans, your diet falls short of the recommended intakes for some vitamins and minerals? Should you take a multi?
It depends how far you fall short. If your diet is merely “suboptimal,” there’s no convincing evidence that you’ll benefit from a multi. If, however, you have severe deficiencies (because of malnutrition, for instance, or absorption problems), targeted supplementation, under medical supervision, may be necessary. If you are living totally on junk food, no supplement— even one with dozens of components—can make up for the vitamins, minerals and other potentially beneficial compounds found in vegetables, fruits, whole grains and the rest of a healthy balanced diet.
Are multis safe? There’s no evidence of harm from those supplying 100 percent of the recommended intakes (listed as Daily Values on the labels). But again, multis vary so much, it’s hard to give them all a pass. And some contain nutrients that can be dangerous in very high doses (such as beta carotene, vitamins E and A, iron, zinc, selenium or copper) or include herbs and other substances of unknown safety.
This post is quoted from an article on BerkeleyWellness.com: http://www.berkeleywellness.com/supplements/vitamins/article/should-you-still-take-multi?s=EFA_140701_001&st=email&ap=ed