Vitamin D levels do not factor in IVF success

Serum levels of vitamin D do not appear to affect in-vitro fertilization (IVF) outcomes such as clinical pregnancy rate (CPR), live birth rate (LBR), and ongoing pregnancy rate (OPR), according to the results of a meta-analysis.

The meta-analysis included 14 studies evaluating the possible association between vitamin D serum levels and IVF outcomes. These studies contributed to a total of 4,382 women. Vitamin D levels were classified into three groups: deficient (<20 ng/mL), insufficient (20−30 ng/mL), and replete (>30 ng/mL).

Pooled data revealed that compared with women who had deficient of insufficient level of vitamin D, those with a replete level had higher CPR (odds ratio [OR], 0.68, 95 percent confidence interval [CI], 0.48–0.98; I², 57 percent; p=0.04) and LBR/OPR (OR, 0.72, 95 percent CI, 0.53–0.97; I², 29 percent; p=0.03).

However, the associations disappeared on a sensitivity analysis (CPR: OR, 0.71, 95 percent CI, 0.47−1.08; I², 61 percent; OPR/LBR: OR, 0.78, 95 percent CI, 0.56−1.08; I², 61 percent).

Results were not significant for miscarriage.

The findings suggest that vitamin D serum levels assessed before IVF cycles should not be considered as a prognostic factor for IVF success. Nevertheless, additional investigation is warranted to establish the role of vitamin D in reproductive medicine and determine whether the threshold of vitamin D studied in relation to reproductive health is extremely low compared to those used for bone healthcare and whether it differs among different ethnic groups.