Role of vitamin D in hair loss: A short review.

BACKGROUND: Vitamin D, a vitamin and hormone, plays an important role in dermatology and dermatotherapeutics, due to its anti-inflammatory and immunomodulatory properties, and regulation of keratinocyte differentiation and proliferation. It also affects the hair cycle, and its role in hair loss is under constant research. OBJECTIVES: This review aims to give a brief overview of vitamin D biology within the hair follicle, role in the etiopathogenesis, and rationale for supplementation in various alopecias. METHODS: A PubMed literature search was performed to review relevant current literature and studies investigating the role of vitamin D in the etiopathogenesis, as a supplement and a potential therapeutic modality in hair loss. RESULTS AND CONCLUSION: Vitamin D is intricately involved in various signaling pathways of growth and differentiation of hair follicles. Most studies show an inverse relationship between serum vitamin D levels and non-scarring alopecias such as telogen effluvium, androgenetic alopecia, alopecia areata, and trichotillomania. Vitamin D deficiency is also associated with scarring alopecia. However, conclusive studies to demonstrate the benefit of vitamin D administration in correcting hair loss and managing these conditions are lacking. Hence, further studies are needed before vitamin D can be routinely recommended as a treatment modality in these conditions.