Background: Alopecia areata [AA] is a frequent autoimmune disease, the pathogenesis of which is still unknown. Androgenic alopecia [AGA] is a non cicatricial or potentially reversible type of patterned hair loss, in which genetic predisposition and hormonal factors play a role. Expression of vitamin D receptors (VDR) on keratinocytes is necessary for maintenance of the normal hair cycle specially anagen initiation. The relation between VDR and both AA and AGA represents an attractive area of research. Purpose: Assessment of VDR in the skin and blood of AA and AGA patients, in order to evaluate their possible role in these hair diseases. Patients and methods: This study recruited 20 patients with AA, 20 patients with AGA and 20 healthy controls. Blood samples and lesional scalp biopsies were taken from all participants for the detection of VDR levels. Serum ferritin and TSH were measured for all AGA patients and controls, in addition to serum free testosterone for females of both groups. Results: Serum and tissue VDR levels were lower in AA as well as AGA patients when compared to controls, with highly significant difference (p=0.000). Serum and tissue VDRs were positively correlated in each group. Tissue VDR was significantly lower in female AA patients than males (p=0.046) though serum and tissue VDR levels were significantly higher in female AGA patients than males (p=0.004). Serum testosterone levels were significantly lower in female AGA patients than female controls (p=0.019). Serum ferritin levels were significantly lower in AGA patients than controls (p=0.000). Conclusion: The current study suggests an important role for VDR in the pathogenesis of AA and AGA through documenting lower serum and tissue VDR levels in AA and AGA patients in comparison to the controls.