Association of vitamin D level with alopecia areata

Background: Alopecia areata (AA) is an autoimmune disorder of hair follicles. We aimed to find the association between VitaminD level and AA. Method: Eligible AA patients and controls were enrolled in this case-control study and serum samples were assessed for 25-hydroxy vitamin D (25-(OH)-D3). The levels of 25-(OH)-D3 were categorized as deficient (<10ng/ml), insufficient (10 to <30 mg/ml) and sufficient (>30ng/dl) and the SALT (Severity of Alopecia Tool) score was used to assess the severity of the disease. The data was analysed and the association between vitamin D levels and AA, disease distribution, and the pattern of hair loss was investigated. Result: Twenty eight patients (19 males, 9 females) and 44 healthy controls (16 males, 28 females) were assessed. There was no statistically significant difference between patients and controls with regard to the level of 25(OH)D3 when the data was adjusted for gender (Ordinal odds ratio: 0.49 (0.18-1.34 and 95% CI, p-value=0.16). The level of 25(OH)D3 was lower in patients with nail involvement in contrast to those without it (P=0.02); moreover, no significant difference was found between patients with different patterns of hair loss. Conclusion: After adjustment for gender, there was no association between AA and the level of vitamin D.