Meta-analysis finds vitamin D supplementation does not significantly affect ovarian reserve markers in women

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Frontiers in Medicine Published May 11, 2026 Medically reviewed May 11, 2026 DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider that vitamin D supplementation may not improve ovarian reserve markers in women of reproductive age.

This is a meta-analysis synthesizing evidence on vitamin D supplementation and ovarian reserve, measured by serum anti-Müllerian hormone (AMH) levels, in women of reproductive age. The analysis pooled data from 992 participants and found no significant overall effect of vitamin D supplementation compared to placebo or no intervention on serum AMH levels (standardized mean difference [SMD] −0.20; 95% CI −0.48 to 0.08; p = 0.16).

Subgroup analyses indicated no significant effect in double-blind trials, but a reduction in AMH was observed in open-label trials (p for subgroup difference = 0.02). An interaction was noted by baseline AMH level, with a reduction in studies where baseline AMH was greater than 6 ng/mL (SMD −0.55; 95% CI −0.87 to −0.23; p = 0.003).

The authors acknowledge substantial heterogeneity (I² = 77%, p < 0.001) and note that findings should be interpreted cautiously. Safety data were not reported, and the certainty of evidence is moderate.

Practice relevance is not specified in the source. The analysis highlights gaps in trial design and baseline characteristics that may influence outcomes, but does not support routine vitamin D supplementation for improving ovarian reserve markers based on current evidence.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedMay 2026

View Original Abstract ↓

BackgroundVitamin D has been implicated in ovarian physiology, yet its effect on ovarian reserve remains controversial. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the influence of vitamin D supplementation on ovarian reserve as indicated by serum anti-Müllerian hormone (AMH) levels.MethodsPubMed, Cochrane Library, Embase, Web of Science, Wanfang, and CNKI were searched for RCTs comparing vitamin D supplementation with placebo or no intervention on AMH in women of reproductive age. The pooled effect was summarized as standardized mean difference (SMD) using a random-effects model by incorporating the influence of potential heterogeneity.ResultsEleven RCTs with 992 women were included. Overall, vitamin D supplementation did not significantly affect serum AMH levels (SMD: −0.20; 95% CI: −0.48 to 0.08; p = 0.16), with substantial heterogeneity (I² = 77%, p < 0.001). Subgroup analysis showed no significant effect in double-blind trials but a reduction in AMH in open-label trials (p for subgroup difference = 0.02). A significant interaction was observed according to baseline AMH level (p = 0.003), with a reduction in studies where baseline AMH > 6 ng/mL (SMD: −0.55; 95% CI: −0.87 to −0.23). No significant subgroup differences were found by age, baseline 25(OH)D, vitamin D dose, treatment duration, or assay method.ConclusionsCurrent randomized evidence suggests that vitamin D supplementation was not likely to alter AMH levels in reproductive-aged women overall. The certainty of evidence was moderate, and findings should be interpreted cautiously given substantial heterogeneity.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD420261329210.