Zinc, copper, and selenium levels in vitiligo: a systematic review and meta-analysis

Vitiligo is a dermatological disease characterized by loss of melanocytes, causing non-scaly white macules on the skin. Zinc, copper, and selenium are important micronutrients that play a role in the normal functioning of the body and have been found to potentially aid in vitiligo treatment, although the relationship between their serum levels and vitiligo is not yet fully understood. This is a systematic review aimed at assessing the levels of serum zinc, copper, and selenium and their association with vitiligo. This review was performed following the Preferred Reporting Items of the systematic Review and Meta-Analysis (PRISMA) checklist and Cochrane guidelines. A comprehensive literature search was conducted on PubMed, Google Scholar and 41 studies published between 1970 and 2022 including 3353 vitiligo cases and 10,638 controls were included in the meta-analysis conducted from August 2022 till September 2023. The quality of the studies was assessed using the National Heart Lung and Blood Institute Study Quality Assessment tool, and the risk of bias was represented using the RobVis tool. The statistical analysis was performed using Review Manager (RevMan) Version 5.4. This meta-analysis indicate a significant decline in serum zinc levels (Z = 4.97; P < 0.0001; SMD = - 0.86; 95% CI - 1.19 to - 0.52) in vitiligo group with high statistical heterogeneity (Tau2 = 0.74; Chi2 = 513.95, d.f. = 26 [P < 0.00001]; I2 = 95%). Similarly for serum copper levels there was decline (Z = 2.43; P < 0.0001; SMD = - 0.50; 95% confidence interval [CI] - 0.91 to - 0.10) in vitiligo group and high statistical heterogeneity (Tau2 = 0.92; Chi2 = 475.10, d.f. = 22 [P < 0.00001]; I2 = 95%). On the other hand, there was a increase of serum selenium levels in the vitiligo group (Z = 0.56; P < 0.0001; SMD = 0.23; 95% confidence interval [CI], 0.58 to 1.04) and the results reveals high statistical heterogeneity among studies (Tau2 = 1.93; Chi2 = 406.44, d.f. = 11 [P < 0.00001]; I2 = 97%) in vitiligo patients compared to healthy controls. Publication bias was not found for the studies analysed. This study analyses the association of serum micronutrient levels and vitiligo among patients and controls from published research along with sub-group analysis specific to Asian populations using a meta-analysis. Low serum levels of Zinc and copper and high selenium levels are associated with Vitiligo.