They also showed that vitamin D supplementation compared to placebo resulted in significant improvements in indices of insulin resistance including decrease in fasting insulin levels (SMD: −0.43, 95% CI: −0.67, −0.18), HOMA-IR (SMD: −0.25, 95% CI: −0.47, −0.02) and increase in QUICKI (SMD: 0.52, 95% CI: 0.11, 0.92). This evidence concerns the gene INS and Insulin resistance.