Role of vitamin B6 in skin health and diseases

Abstract

Vitamin B6 has been believed to be essential for skin development and maintenance. Additionally, vitamin B6 has long been considered to have an important role in amino acids metabolism as a coenzyme. Vitamin B6 deficiency has been known to be associated with dermatitis, while contact allergy to vitamin B6 is generally rare. There is accumulating evidence that dietary vitamin B6 has protective roles in cardiovascular disease and diabetes. Recent studies have further highlighted the important protective role of vitamin B6 in carcinogenesis, especially colon carcinogenesis. For skin cancer, a recent study has underlined that dietary supplemental vitamin B6 to a low vitamin B6 diet enhanced UV-irradiated skin tumorigenesis in hairless mice. However, dietary vitamin B6 caused no influence on carcinogen-induced skin tumorigenesis in mice. Topical application of vitamin B6 has been reported to exaggerate UV-irradiated skin phototoxicity. The toxic properties of irradiated vitamin B6 compounds have been also demonstrated for human fibroblasts. Thus, there is concern that excessive dose or abuse of vitamin B6 might cause adverse effect on skin health under certain conditions such as strong sunlight despite its essential roles for skin maintenance.