Vitamins

From Maggie's an interesting article at Smithsonian about which vitamins actually have some positive effect. Vitamin D for most of us. Probiotics, but only when you are taking antibiotics.  Zinc, but only for a cold.  Niacin if you have heart disease, and maybe for some other things if you take it at prescription strength. Garlic for high blood pressure. 

Lots of things are absent here.