Research Summary
Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A can have deleterious effects. Retinoic acid and retinal are the main active metabolites of vitamin A. Retinoic acid regulates hair follicle stem cells in a dose-dependent manner, influencing the hair cycle, wound healing, and melanocyte stem cells.
Additionally, retinoic acid affects melanocyte differentiation and proliferation in a temporal and dose-dependent way. The levels of retinoids decrease when the skin is exposed to ultraviolet irradiation. Retinal is required for the phototransduction cascade that initiates melanogenesis, but the source of this retinal remains unknown.
This review highlights new research on retinoids and their effects on the skin and hair.
Keywords: vitamin A, hair follicle stem cells, melanocyte stem cells, melanocyte, retinoids
<Access the full report below>