What to watch with Vitamin D 25-OH and fertility?

When monitoring Vitamin D (25-OH) for fertility, key points include: optimal levels (30–50 ng/ml) are linked to better egg quality, sperm function, and implantation in observational studies, but RCTs show mixed results. Deficiency should be corrected, but excess (toxicity >100 ng/ml) is harmful. Individual dosing depends on baseline, genetics (e.g., VDR variants), and lifestyle. A blood test before supplementation is recommended. MyBody-X offers Vitamin D testing that measures 25-OH levels – but it is not a fertility diagnostic. Evidence is moderate; results are not medical advice. For fertility concerns, consult a healthcare provider.