Vitamins and minerals: powerful medicine or potent toxins?

Purpose The purpose of this review is to summarize the available literature on the effect of vitamin and mineral supplements, especially in doses exceeding recommended daily allowances. Design/methodology/approach A comprehensive search and analysis of original, peer‐reviewed literature on supplementation studies was conducted. Findings High doses of vitamins and minerals can be harmful instead of beneficial. Supplementation of vitamins and minerals, in general, may be most beneficial, and perhaps only beneficial, to individuals with a nutrient‐deficient diet. Consumers thus need to be weary of the safety and efficacy of their supplements. While vitamins and minerals are vital to life, the optimal doses of each required nutrient are currently not known. Research limitations/implications Lack of standardization between studies makes it difficult to compare the results from different studies.Practical implications – Based on this review, a recommendation can be made to avoid high dose supplements and obtain vitamins from foods to the greatest extent possible.Originality/value – This review is unique in its comprehensive nature that allows the identification of common underlying problems with the supplementation of different groups of vitamins.