Vitamin D Levels in Alopecia Areata and Other Alopecias: A Retrospective Case- Control Study at a Single Institution.

Recent research has associated alopecia areata (AA), an autoimmune disorder, with deficiency of Vitamin D, which regulates immune processes. This retrospective study compared Vitamin D levels in AA patients to those of other alopecia diagnoses and nonalopecia controls. When compared to controls, patients with AA or other alopecia diagnoses did not demonstrate lower Vitamin D levels. However, when compared to other alopecia diagnoses, AA patients had a statistically significantly higher proportion of patients with Vitamin D deficiency and a lower mean Vitamin D level. Our findings suggest a greater association between lower Vitamin D levels and AA compared to other alopecia diagnoses. Further prospective studies investigating Vitamin D levels and supplementation in AA patients are needed to further elucidate this association and its potential relevance.