Correlation values between dark adaptation, serum vitamin A, serum zinc, and retinol binding protein using Pearson’s correlation coefficient (r)
| Pearson’s r | Vitamin A | Zinc | RBP | Dark adaptation |
|---|---|---|---|---|
| Vitamin A | 1 | −0.04 | 0.42 | −0.16 |
| Zinc | −0.04 | 1 | −0.25 | −0.04 |
| RBP | 0.42 | −0.25 | 1 | −0.04 |
| Dark adaptation | −0.16 | −0.04 | −0.04 | 1 |