| Serum zinc (μmol/L) | Zinc group (n = 28) | Control group (n = 30) | P value |
| Mean ± SD | Mean ± SD | ||
| Before treatment | 4.37 ± 1.23 | 4.42 ± 1.45 | 0.246 |
| After treatment | 8.81 ± 2.56 | 4.12 ± 1.02 | 0.001 |