Vitamin supplementation in healthy patients: What does the evidence support?

Abstract

Vitamin supplementation in the developed world remains common despite a paucity of RCT data supporting it. Supplementation of folate in women planning to conceive, vitamin D in breastfeeding infants, and vitamin K in newborns are well supported by clinical evidence. Otherwise, there is limited evidence supporting clinically significant benefit from supplementation in healthy patients with well-balanced diets-and in the case of vitamins A and E, there may be outright harms.