Table 4.
Serum zinc, vitamin B12, folic acid, vitamin E, and vitamin C levels between the vitiligo and control groups.
| Studies | Vitiligo group | Control group | MD [95% CI] | p-value | ||
|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | |||
| 1. Zinc | ||||||
| Khoshdel et al. (2022) (41) | 95.01 | 58.95 | 121.83 | 33.8 | −0.570 [−0.821–−0.318] | |
| Zaki et al. (2020) (42) | 50.93 | 11.02 | 77.09 | 12.16 | −2.254 [−2.758–−1.751] | |
| Wacewicz et al. (2018) (43) | 0.848 | 0.12 | 0.997 | 0.292 | −0.650 [−1.038–−0.262] | |
| Mirnezami et al. (2018) (44) | 85.4 | 14.1 | 91.8 | 16.2 | −0.421 [−0.698–−0.144] | |
| Narang et al. (2017) (45) | 20.05 | 7.89 | 32.72 | 0.68 | −1.794 [−2.682–−0.905] | |
| Mogaddam et al. (2017) (47) | 80.11 | 17.1 | 96.1 | 16.16 | −0.961 [−1.254–−0.668] | |
| Dogan et al. (2016) (48) | 92.84 | 15.51 | 88.94 | 13.43 | 0.269 [−0.117–0.655] | |
| Arora et al. (2002) (58) | 97.3 | 26.6 | 105.3 | 30.1 | −0.278 [−0.926–0.371] | |
| Haider et al. (2010) (65) | 1.08 | 0.07 | 0.95 | 0.35 | 0.515 [0.000–1.030] | |
| Jialing Song et al. (2017) (79) | 0.84 | 0.12 | 1.1 | 0.2 | −1.576 [-1.980–−1.173] | |
| Caixia Tu et al. (1991) (77) | 11.5 | 3.15 | 13.54 | 2.34 | −0.751 [−1.268–−0.235] | |
| Xiaohua Wang et al. (1996) (76) | 74.23 | 18.99 | 97.4 | 13.8 | −1.517 [−1.879–−1.155] | |
| Yi Wu et al. (2010) (75) | 6.416 | 1.758 | 7.193 | 1.412 | −0.487 [−0.824–−0.151] | |
| Fei Wang et al. (1993) (74) | 0.9 | 0.51 | 1.06 | 2.25 | −0.098 [−0.574–0.378] | |
| Aiping Yao et al. (2011) (71) | 0.88 | 0.26 | 1.07 | 0.31 | −0.682 [−1.036–−0.327] | |
| Yandong Wang et al. (2012) (69) | 12.79 | 2.31 | 13.02 | 3.53 | −0.077 [−0.330–0.176] | |
| Xuemin Wang et al. (2011) (70) | 9.9 | 0.51 | 15.62 | 2.94 | −2.667 [−3.380–−1.953] | |
| Al-Hattab et al. (2020) (80) | 82.49 | 23.92 | 98.78 | 36.62 | −0.527 [−0.926–−0.128] | |
| Meta-analysis (random, I2 = 91.3%) | −0.774 [−1.083–−0.466] | 0.000* | ||||
| 1.1 Vitiligo type | ||||||
| 1.1 Generalized vitiligo | ||||||
| Mirnezami et al. (2018) (44) | 81.3 | 12.7 | 91.8 | 16.2 | −0.701 [−1.024–−0.379] | |
| Khoshdel et al. (2022) (41) | 93.11 | 59.33 | 121.83 | 33.8 | −0.624 [−0.891–−0.357] | |
| Yi Wu et al. (2010) (75) | 5.401 | 1.198 | 7.193 | 1.412 | −1.306 [−1.859–−0.752] | |
| Meta-analysis (random, I2 = 58.3%) | −0.799 [−1.121–−0.477] | 0.000* | ||||
| 1.1.2 Focal vitiligo | ||||||
| Mirnezami et al. (2018) (44) | 92.1 | 13.8 | 91.8 | 16.2 | 0.019 [−0.349–0.388] | |
| Khoshdel et al. (2022) (41) | 98.69 | 58.63 | 121.83 | 33.8 | −0.610 [−1.075–−0.146] | |
| Yi Wu et al. (2010) (75) | 6.767 | 1.793 | 7.193 | 1.412 | −0.269 [−0.629–0.092] | |
| Meta-analysis (random, I2 = 54.3%) | −0.264 [−0.601–0.073] | 0.125 | ||||
| 1.2 Sex | ||||||
| 1.2.1 Female | ||||||
| Khoshdel et al. (2022) (41) | 92.55 | 56.83 | 112.53 | 33.78 | −0.438 [−0.769–−0.107] | |
| Wacewicz et al. (2018) (43) | 0.812 | 0.101 | 0.987 | 0.281 | −0.778 [−1.271–−0.284] | |
| Meta-analysis (fixed, I2 = 20.3%) | −0.557 [−0.874–−0.240] | 0.001* | ||||
| 1.2.2 Male | ||||||
| Khoshdel et al. (2022) (41) | 99.12 | 62.1 | 126.87 | 29.28 | −0.597 [−0.982–−0.212] | |
| Wacewicz et al. (2018) (43) | 0.897 | 0.129 | 1.021 | 0.325 | −0.523 [−1.174–0.128] | |
| Meta-analysis (fixed, I2 = 0.0%) | −0.578 [−0.909–−0.246] | 0.0000* | ||||
| 1.3 Vitiligo disease activity | ||||||
| 1.3.1 Progressive | ||||||
| Jialing Song et al. (2017) (79) | 0.67 | 0.1 | 1.1 | 0.2 | −2.556 [−3.089–−2.024] | |
| Yandong Wang et al. (2012) (69) | 13.2 | 3.44 | 13.02 | 3.53 | 0.051 [−0.266–0.369] | |
| Meta-analysis (random, I2 = 98.5%) | −1.243 [−3.798–1.312] | 0.340 | ||||
| 1.3.2 Stable | ||||||
| Jialing Song et al. (2017) (79) | 0.95 | 0.14 | 1.1 | 0.2 | −0.804 [−1.306–−0.303] | |
| Yandong Wang et al. (2012) (69) | 12.83 | 2.86 | 13.02 | 3.53 | −0.057 [−0.361–0.246] | |
| Meta-analysis (random, I2 = 84.8%) | −0.403 [−1.133–0.327] | 0.279 | ||||
| 2.Vitamin B12 | ||||||
| Bagheri Hamidi et al. (2020) (46) | 384.62 | 198.63 | 434.1 | 177.86 | −0.262 [−0.538–0.014] | |
| Ataş et al. (2015) (49) | 372 | 142 | 348 | 121 | 0.182 [−0.177–0.541] | |
| Yasar et al. (2012) (52) | 212.9 | 81.67 | 241.15 | 126.23 | −0.266 [−0.706–0.175] | |
| Karadag et al. (2012) (53) | 250.6 | 112.4 | 316.5 | 152 | −0.504 [−0.869–−0.138] | |
| Balci et al. (2009) (54) | 211.69 | 211.38 | 198.32 | 103.49 | 0.075 [−0.376–0.527] | |
| Park et al. (2005) (57) | 668 | 290 | 875 | 302 | −0.699 [−1.021–−0.376] | |
| Kim et al. (1999) (59) | 630.25 | 230.94 | 627.16 | 251.35 | 0.013 [−0.395–0.421] | |
| Hussein et al. (2019) (17) | 186 | 11.5 | 399.23 | 19 | −13.751 [−16.012–−11.491] | |
| Meta-analysis (random, I2 = 94.8%) | −0.951 [−1.672–−0.275] | 0.006# | ||||
| 3. Folic acid | ||||||
| Ataş et al. (2015) (49) | 9.8 | 2.9 | 10.2 | 2.7 | −0.400 [−1.403–0.603] | |
| Yasar et al. (2012) (52) | 6.59 | 2.78 | 5.39 | 2.41 | 1.200 [0.060–2.340] | |
| Karadag et al. (2012) (53) | 7.5 | 3.1 | 7 | 2.2 | 0.500 [−0.445–1.445] | |
| Balci et al. (2009) (54) | 6.14 | 2.45 | 6.25 | 3.44 | −0.110 [−1.505–1.285] | |
| Kim et al. (1999) (59) | 6.31 | 2.82 | 6.11 | 3.11 | 0.200 [−1.043–1.443] | |
| Hussein et al. (2019) (17) | 1.22 | 0.2 | 11.33 | 0.67 | −10.110 [−10.337–−9.883] | |
| Meta-analysis (random, I2 = 99.6%) | −1.463 [−7.133–4.208] | 0.613 | ||||
| 4.Vitamin E | ||||||
| Ramadan et al. (2013) (51) | 1.04 | 0.22 | 5.21 | 0.5 | −10.796 [−13.712–−7.879] | |
| Jain et al. (2008) (55) | 0.7 | 0.43 | 1.13 | 0.57 | −0.852 [−1.310–−0.394] | |
| Ines et al. (2006) (56) | 9.43 | 7.98 | 9.18 | 9.87 | 0.028 [−0.423–0.478] | |
| Agrawal et al. (2014) (50) | 0.67 | 0.22 | 0.66 | 0.15 | 0.053 [−0.257–0.363] | |
| Meta-analysis (random, I2 = 93.8%) | −1.408 [−2.611–−0.206] | 0.022# | ||||
| 5.Vitamin C | ||||||
| Haider et al. (2010) (65) | 25.01 | 7.14 | 25.94 | 7.98 | −0.123 [−0.629–0.384] | |
| Agrawal et al. (2014) (50) | 0.65 | 0.15 | 0.63 | 0.14 | 0.138 [−0.172–0.448] | |
| Al-Hattab et al. (2020) (80) | 6.27 | 2.65 | 10.83 | 5.52 | −1.053 [−1.472–−0.634] | |
| Meta-analysis (random, I2 = 90.2%) | −0.342 [−1.090–0.407] | 0.371 | ||||
| 6.Copper | ||||||
| Khoshdel et al. (2022) (41) | 113.57 | 59.43 | 138.9 | 38.14 | −0.516 [−0.767–−0.265] | |
| Narang et al. (2017) (45) | 31.7 | 10.28 | 22.52 | 1.95 | 0.994 [0.177–1.811] | |
| Wacewicz et al. (2018) (43) | 1.099 | 0.273 | 1.038 | 0.336 | 0.198 [−0.181–0.577] | |
| Jialing Song et al. (2017) (79) | 0.8 | 0.12 | 1.15 | 0.23 | −1.908 [−2.334–−1.482] | |
| Caixia Tu et al. (1991) (77) | 13.05 | 2.74 | 14.08 | 2.33 | −0.410 [−0.914–0.094] | |
| Xiaohua Wang et al. (1996) (76) | 107.6 | 10.16 | 109.2 | 16.7 | −0.104 [−0.432–0.223] | |
| Yi Wu et al. (2010) (75) | 1.46 | 0.471 | 1.536 | 0.345 | −0.184 [−0.516–0.148] | |
| Fei Wang et al. (1993) (74) | 0.88 | 0.17 | 1.13 | 0.21 | −1.309 [−1.834–−0.783] | |
| Aiping Yao et al. (2011) (71) | 0.69 | 0.15 | 1.12 | 0.2 | −2.538 [−2.995–−2.080] | |
| Yandong Wang et al. (2012) (69) | 13.1 | 2.56 | 14.78 | 2.4 | −0.677 [−0.937–−0.417] | |
| Xuemin Wang et al. (2011) (70) | 18.95 | 0.39 | 19.35 | 4.32 | −0.128 [−0.644–0.387] | |
| Zongping Li et al. (2001) (73) | 0.807 | 0.143 | 1.091 | 0.181 | −1.859 [−2.330–−1.389] | |
| Meta-analysis (random, I2 = 94.2%) | −0.719 [−1.185–−0.252] | 0.003# | ||||
| 6.1 Vitiligo disease activity | ||||||
| 6.1.1 Progressive | ||||||
| Jialing Song et al. (2017) (79) | 0.65 | 0.1 | 1.1 | 0.2 | −2.675 [−3.219–−2.131] | |
| Yandong Wang et al. (2012) (69) | 13.18 | 2.68 | 13.02 | 3.53 | 0.049 [−0.269–0.366] | |
| Meta-analysis (random, I2 = 98.6%) | −1.304 [−3.973–1.365] | 0.338 | ||||
| 6.1.2 Stable | ||||||
| Jialing Song et al. (2017) (69) | 1.04 | 0.17 | 1.1 | 0.2 | −0.311 [−0.800–0.177] | |
| Yandong Wang et al. (2012) (79) | 12.9 | 3.28 | 13.02 | 3.53 | −0.035 [−0.338–0.269] | |
| Meta-analysis (fixed, I2 = 0.0%) | −0.112 [−0.369–0.146] | 0.396 | ||||
| 6.2 Sex | ||||||
| 6.2.1 Female | ||||||
| Khoshdel et al. (2022) (41) | 112.95 | 56.32 | 146.22 | 34.76 | −0.718 [−1.055–−0.380] | |
| Wacewicz et al. (2018) (43) | 1.128 | 0.317 | 1.118 | 0.348 | 0.030 [−0.446–0.505] | |
| Meta-analysis (random, I2 = 84.2%) | −0.364 [−1.095–0.368] | 0.330 | ||||
| 6.2.2 male | ||||||
| Khoshdel et al. (2022) (41) | 114.65 | 63.88 | 135.46 | 25.13 | −0.451 [−0.832–−0.069] | |
| Wacewicz et al. (2018) (43) | 1.058 | 0.196 | 0.845 | 0.21 | 1.053 [0.369–1.737] | |
| Meta-analysis (random, I2 = 92.9%) | 0.273 [−1.199–1.745] | 0.716 | ||||
| 7. Selenium | ||||||
| Wacewicz et al. (2018) (43) | 51.3 | 13.99 | 79.42 | 18.97 | −1.669 [−2.109–−1.229] | |
| Barikbin et al. (2011) (66) | 1.021 | 0.04 | 0.909 | 0.01 | 3.616 [2.989–4.243] | |
| Ozturk et al. (2008) (67) | 122.333 | 30.173 | 120.766 | 21.802 | 0.060 [−0.447–0.566] | |
| Beazley et al. (1999) (68) | 1.27 | 0.32 | 0.93 | 0.2 | 1.687 [1.433–1.941] | |
| Caixia Tu et al. (1998) (78) | 99.41 | 14.93 | 105.24 | 14.92 | −0.391 [−0.881–0.100] | |
| Jialing Song et al. (2017) (79) | 0.11 | 0.02 | 0.16 | 0.05 | −1.313 [−1.702–−0.924] | |
| Fei Wang et al. (1993) (74) | 0.1 | 0.02 | 0.13 | 0.14 | −0.300 [−0.778–0.178] | |
| Jin Zhao et al. (2011) (72) | 121.9 | 46.16 | 129.27 | 23.67 | −0.181 [−0.771–0.409] | |
| Aiping Yao et al. (2011) (71) | 0.09 | 0.03 | 0.14 | 0.07 | −1.038 [−1.405–−0.671] | |
| Ines et al. (2006) (56) | 1.37 | 0.19 | 0.93 | 0.07 | 3.138 [2.461–3.815] | |
| Meta-analysis (random, I2 = 98.2%) | 0.350 [−0.687–1.387] | 0.508 | ||||
| 7.1 Vitiligo disease activity | ||||||
| 7.1.1 Progressive | ||||||
| Jialing Song et al. (2017) (79) | 0.06 | 0.01 | 0.16 | 0.05 | −2.529 [−3.059–−1.999] | |
| Jin Zhao et al. (2011) (72) | 121.08 | 44.83 | 129.27 | 23.67 | −0.225 [−0.900–0.451] | |
| Meta-analysis (random, I2 = 98.0%) | −1.387 [−3.644–0.871] | 0.229 | ||||
| 7.1.2 Stable | ||||||
| Jialing Song et al. (2017) (79) | 0.12 | 0.03 | 0.16 | 0.05 | −0.875 [−1.379–−0.370] | |
| Jin Zhao et al. (2011) (72) | 122.72 | 48.74 | 129.27 | 23.67 | −0.168 [−0.842–0.507] | |
| Meta-analysis (random, I2 = 63.1%) | −0.558 [−1.247–0.131] | 0.112 | ||||
| 8. Iron | ||||||
| Fei Wang et al. (1993) (74) | 2.37 | 0.78 | 1.35 | 0.51 | 1.548 [1.004–2.092] | |
| Aiping Yao et al. (2011) (71) | 2.28 | 0.61 | 1.37 | 0.46 | 1.621 [1.226–2.016] | |
| Xuemin Wang et al. (2011) (70) | 25.67 | 7.92 | 23.09 | 6.8 | 0.350 [−0.169–0.870] | |
| Meta-analysis (random, I2 = 89.8%) | 1.181 [0.390–1.972] | 0.003# | ||||
CI, confidence interval; RR, risk ratio; #p < 0.005; *p <0.001.