Serum Vitamin D Level and Disease Severity of Alopecia Areata: A Meta-Regression Analysis

The document presents a meta-regression analysis examining the relationship between serum vitamin D levels and disease severity in patients with alopecia areata (AA). The analysis included a total of 6 studies, but only one provided both mean and standard deviation of vitamin D levels and disease severity scores. The results showed a non-statistically significant, slightly negative correlation between vitamin D levels and disease severity in AA patients. The paper suggests that while lower vitamin D levels have been observed in AA patients, and vitamin D may act as an immune modulator, the benefit of vitamin D supplementation for AA remains unclear. A pilot study mentioned in the document indicated that 59.1% of patients experienced hair regrowth after using a topical vitamin D preparation for 3 months, with those having lower vitamin D levels responding better. The document concludes that further research is needed to explore the potential therapeutic effects of vitamin D for AA, acknowledging limitations such as geographic and seasonal variations in vitamin D levels, heterogeneity of study groups, and a limited number of studies.