Serum level of antioxidant vitamins and minerals in patients with vitiligo, a systematic review and meta-analysis.

BACKGROUND

Antioxidant status is considered as important factor in the pathogenesis of vitiligo. However, there are controversial findings about serum status of antioxidants in vitiligo patients. The purpose of this study was to systematically review the evidences comparing the serum levels of antioxidant vitamins and minerals between vitiligo patients and controls, and performing meta-analysis of the results.

METHODS

A comprehensive search was performed for studies comparing the serum status of antioxidant vitamins and minerals using following databases since inception up to 30 April 2020; PubMed, EMBASE, Scopus, and Web of Science. Data extraction was done by two independent reviewers. The data was pooled for serum level of each antioxidant comparing between vitiligo and control groups.

RESULTS

Thirteen studies were included in this systematic review. The serum level of vitamin A, C, E, selenium, zinc and copper were compared between vitiligo patients and controls in these studies. Eleven studies including 570 vitiligo cases and 580 controls were included in the meta-analysis. Serum vitamin A and copper level in vitiligo patients were only evaluated in single studies and not included in meta-analysis. Based on fixed effect model, there were no statistical difference between two groups regarding serum vitamin C (OR = 1.17, 95 % CI, 0.74-1.84, P = 0.495), and vitamin E (OR = 0.61, 95 % CI, 0.30-1.25, P = 0.180). Higher serum zinc can decrease the risk of vitiligo based on sensitivity analysis of the results. (OR = 0.29, 95 % CI 0.15-0.54, P < 0.001). Higher serum selenium level significantly increased the risk of vitiligo (OR = 4.31, 95 % CI, 2.72-6.81, P < 0.001). Vitamin A was not significantly different in two reported groups (6.35 ± 1.53 vs 6.77 ± 1.46 μg/mL, P > 0.05). Copper was significantly higher in vitiligo patients compared to controls (129 ± 33 vs 99 ± 19 μg /100 mL, P = 0.002).

CONCLUSION

The current meta-analysis of data on serum level of most studied antioxidants (vitamin C, vitamin E, zinc and selenium) in patients suffering vitiligo showed that higher serum selenium (OR = 4.31) and lower zinc level (OR = 0.29) can increased the risk of vitiligo. Potential mechanism associated with preventive effects of zinc and the depigmentation effect of selenium should be more elucidated in further studies.