Many mega dose vitamin supplements are associated with higher cancer risks - folic acid and beta carotene. Paradoxically, the same vitamins are known to reduc

Many mega dose vitamin supplements are associated with higher cancer risks - folic acid and beta carotene. Paradoxically, the same vitamins are known to reduce cancer risk when obtained from food sources. The reasons behind this are poorly understood, and it's possible that confounding factors are to blame. But either way, nutrient rich food is exceedingly easy to obtain for mid-to-high income people in developed nations. For this category of people, vitamin supplements are almost completely useless and potentially harmful.