Association Between Vitamin D Level and Clinical Outcomes of Assisted Reproductive Treatment: A Systematic Review and Dose-Response Meta-Analysis
What this study found
Overall, higher vitamin D status was associated with better assisted reproductive outcomes, especially clinical pregnancy and live birth. Deficient vitamin D versus non-deficient status was associated with lower clinical pregnancy rate (OR 0.81, 95% CI 0.70–0.95, P = 0.01) and live birth rate (OR 0.69, 95% CI 0.54–0.89, P = 0.003). Deficient plus insufficient vitamin D versus sufficient vitamin D was also associated with lower clinical pregnancy rate (OR 0.71, 95% CI 0.55–0.91, P = 0.007) and live birth rate (OR 0.69, 95% CI 0.54–0.89, P = 0.003). Biochemical pregnancy, ongoing pregnancy,…
- Study & population
- Systematic review and dose-response meta-analysis of women undergoing assisted reproductive treatment, including IVF and ICSI, with vitamin D measured in serum or follicular fluid.
- Intervention
- Vitamin D exposure was evaluated as serum or follicular fluid vitamin D status in women undergoing assisted reproductive treatment, categorized across included studies as deficient, insufficient, and sufficient.
- Key limitation
- The evidence is based on observational studies rather than randomized trials, so confounding and reverse causation remain possible.
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Open PDFOriginal abstract
The investigation about association between vitamin D level and clinical outcomes of assisted reproductive treatment showed various outcomes. This study aimed to review the correlation between vitamin D and outcomes of assisted reproductive treatment. The search was registered on the PROSPERO database (CRD42023458040). PubMed, Embase, Medline, ClinicalTrials.gov, and Cochrane databases were searched up to July 2023. Twenty-three observational studies were selected for meta-analysis. Comparing groups with deficient and ‘insufficient + sufficient’ vitamin D level, meta-analysis showed positive correlation between clinical pregnancy rate and vitamin D (OR 0.81, 95%CI: 0.70, 0.95, P = 0.0001). Comparing groups with ‘deficient + insufficient’ and sufficient vitamin D level, meta-analysis showed positive correlation between vitamin D and clinical pregnancy rate (OR 0.71, 95%CI: 0.55, 0.91, P = 0.006), vitamin D and live birth rate (OR 0.69, 95%CI: 0.54, 0.89, P = 0.003). Subgroup analysis did not show the source of high heterogeneity. No correlation was found in biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. In dose-response meta-analysis, a nonlinear association was found between vitamin D levels and outcomes when levels are below approximately 24 ng/L. The study shows that vitamin D level is associated with clinical pregnancy rate and live birth rate. Low vitamin D level does not influence biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. Furthermore, 24 ng/L may be a possible threshold of vitamin D concentration in assisted reproduction therapy.