After decades of study, researchers still can't agree on whether nutritional supplements actually improve health.

(.. tl;dr ..)

So, back to the original question. Are supplements useless? The current state of research offers only an equivocal half-answer: 'maybe yes' for some individuals, nutrients and doses, and 'maybe no' for others. “Nutrition is complex, and I don't think we're necessarily going to find one formula that works for everybody,” says Mayne. But new tools in development could “really change the way we look at this”. The big question is whether, once scientists have all the pieces they need, they can put them together to create a clear and cohesive picture.

http://www.nature.com/ne...?WT.mc_id=TWT_NatureNews