Vitamin D and TMPRSS2: Intersecting Pathways in Post-COVID-19 Alopecia

The document discusses the relationship between COVID-19 and post-infectious hair loss, focusing on the roles of cytokine-induced inflammation, androgen-regulated TMPRSS2 expression, and vitamin D. COVID-19-related alopecia is associated with cytokine-mediated inflammation, increased TMPRSS2 expression due to androgens, and direct viral damage to hair follicles. Vitamin D is proposed as a potential dual-action strategy to prevent or reduce hair loss by suppressing inflammatory responses and downregulating TMPRSS2 expression. The study calls for further clinical and translational research to evaluate the protective effects of vitamin D in this context.