This systematic review and meta-analysis, conducted in 2023, aimed to investigate the effect of vitamin D supplementation on the clinical pregnancy rate among infertile women. The study analyzed the results of multiple randomized controlled trials (RCTs) and included a total of 2,000 infertile women who received either vitamin D supplementation or a placebo.
The pooled results of the RCTs showed that vitamin D supplementation significantly increased the clinical pregnancy rate by 70% compared to the control group. This finding suggests that vitamin D supplementation could be a promising intervention for improving fertility outcomes among infertile women.
The study also performed a subgroup analysis to identify the factors that influence the effect of vitamin D supplementation on pregnancy rate. The research found that vitamin D supplementation was particularly effective when the baseline 25(OH)D level was below 30ng/mL, the daily dose was between 1,000-10,000 IU (25-250 mcg), and the supplement duration was longer than 30 days.
Overall, this systematic review and meta-analysis provide evidence that vitamin D supplementation may effectively improve clinical pregnancy rates among infertile women, particularly those with low baseline 25(OH)D levels.