Serum 25-Hydroxy Vitamin D Level in Patients with Alopecia Areata and Its Relationship with Severity of the Disease

Background: Alopecia areata (AA) is a common autoimmune disease in which autoantigens play an important role in activating T lymphocytes. Vitamin D is associated with various autoimmune diseases and Vitamin D receptors are strongly expressed in hair follicles and their expression in keratinocytes is necessary for the maintenance of the normal hair cycle. Several studies showed that there is an influence of vitamin D on patients with AA. Aims and Objectives: To find out serum 25-Hydroxy vitamin D level in patients with AA and its relationship with severity of the disease in a tertiary care hospital. Method: This cross-sectional study was conducted at the Department of Dermatology and Venereology in Dhaka Medical College Hospital (DMCH), Dhaka, from January 2019 to December 2019. A total of sixty-four subjects were enrolled. Among them thirty-two patients were with clinically diagnosed AA cases (Group A) and thirty-two healthy age and gender matched controls without AA (Group B). Serum 25-Hydroxy vitamin D was analyzed by the automated analyzer. The levels of serum 25-Hydroxy vitamin D were categorized as deficient (<20 ng/ml), insufficient (20 to 29.9 ng/ml) and normal (e”30 ng/ml) and the Severity of Alopecia Tool (SALT) score was used to assess the severity of the disease. p-value <0.05 was taken as significant. Statistical analyses were performed with SPSS version 25.0. Results: The mean age of Group A was 30.56 ± 13.52 years and Group B was 34.97 ± 13.03 years. The mean serum 25-Hydroxy vitamin D level was significantly lower in patients with alopecia areata (13.38± 7.36 ng/mL) as compared to the healthy group (23.16 ± 10.36 ng/mL) (p < 0.0004). Deficient, insufficient and normal Vitamin D levels among Group A vs Group B were (88% vs 44%), (9% vs 41%) and (3% vs 16%) respectively with significant difference (p- value 0.001) between the groups. There was a significant negative correlation between serum 25-Hydroxy vitamin D level and SALT score (r=-.509, p=0.003). Conclusions: This study revealed that the prevalence of serum 25-Hydroxy vitamin D deficiency was significantly higher in alopecia areata group compared to healthy group. There was a significant inverse correlation between its level and alopecia areata disease severity. J Dhaka Med Coll. 2023; 32(2) : 100-106