Forest plot of meta-analysis results. Included studies account for n = 353 women. A clinical pregnancy was achieved in 46/115 (40%) women with vitamin D deficiency, and in 109/238 (46%) in those with sufficient serum 25(OH)D levels, yielding a RR of 0.89 (95% CI 0.53 to 1.49) showing a lower but not statistically significant likelihood of CP for vitamin D deficient women undergoing IVF/ICSI procedures compared with vitamin D sufficient patients. Please note that in the study by Firouzabadi et al. all patients with vitamin D deficiency had serum 25(OH)D levels < 10 ng/ml while all those with sufficient serum 25(OH)D levels had serum 25(OH)D levels > 30 ng/ml. CI = confidence interval. M-H = Mantel-Haenszel. RR = Risk Ratio.