The effect of vitamin A on Alopecia areata: A case–control study

Abstract

Introduction: Alopecia areata is an immune-mediated, non-scarring hair loss disorder affecting hair follicles. It is common in the general population and affects both women and men across all age groups. Stress is considered both a triggering factor and a determinant of disease severity. Topical vitamin A derivatives (tretinoin, adapalene) are used in the treatment of alopecia areata. Based on the therapeutic effects of topical vitamin A derivatives, this study aimed to investigate whether serum vitamin A plays a role in the etiopathogenesis of alopecia areata.

Material and Methods: The study included 34 patients with alopecia areata and 38 individuals in the control group. Informed consent was obtained from all participants. Demographic characteristics, disease severity, and involvement sites were recorded for the alopecia areata group. Disease severity was assessed according to the Olsen/Canfield criteria. Controls were selected from patients and accompanying relatives who presented to the outpatient clinic for cosmetic consultation and had no chronic or dermatological diseases. Vitamin A was analyzed in serum samples from both groups. Stress levels in both groups were assessed using a visual analog scale (VAS) ranging from 0 to 10. Ethical approval for the study was obtained. p-value <0.05 was considered statistically significant.

Results: All patients in the alopecia areata group had mild disease. Nevus flammeus was observed in four patients (11.8%). Nail involvement was detected in 7 patients (20.6%). One patient had concomitant atopy, and 4 patients (11.8%) reported a history of hypothyroidism. Age (p=0.050) and sex (p=0.157) distributions were similar between groups. The mean serum vitamin A level in the alopecia areata group was 8.58 mcg/dL (SD ± 0.9), with a median of 8.73 mcg/dL (7.95–9.12). In the control group, the mean was 8.87 mcg/dL (SD ± 1.36) and the median was 9.18 mcg/dL (8.21–9.81). Although the mean and median vitamin A levels were lower in the alopecia areata group, the difference was not statistically significant (z=1.895; p=0.058). When stress levels were compared, VAS were 4.82 in the alopecia areata group and 2 in the control group. Stress levels were significantly higher in the patient group (z=4.929; p=0.000).

Conclusion: Serum vitamin A levels were lower in the alopecia areata group than in controls; however, the difference was not statistically significant. All patients in this study had mild disease severity, which may explain the lack of statistical significance. We recommend further large-scale studies including patients with more severe disease to better elucidate the relationship between alopecia areata and vitamin A.