Determination of Serum 25-Hydroxyvitamin D Levels in Patients with Alopecia Areata and Comparison with Healthy Controls: A Cross-Sectional Study

Three cross-sectional studies examined the relationship between vitamin D levels and alopecia areata (AA). The first study of 100 patients found that those with AA had significantly lower levels of serum 25-hydroxyvitamin D compared to healthy controls, suggesting a role for vitamin D deficiency in AA. The second study, involving 29 patients, found no significant difference in mean vitamin D levels between AA patients and controls, but noted a trend towards a higher percentage of vitamin D deficiency among AA patients. The third study identified factors that could indicate AA patients who might benefit from vitamin D testing, including high SALT scores, younger age, female sex, less than 30 minutes of sun exposure per day, and lighter skin phototype. It also found that AA patients practiced more photoprotection measures, potentially contributing to vitamin D deficiency. All studies suggested further research into the role of vitamin D in AA and the potential benefits of supplementation for deficient patients.