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

During menopause, declining estrogen levels impair vitamin D metabolism and increase the risk of osteoporosis. Monitoring 25-OH vitamin D is crucial because low levels accelerate bone loss. Evidence suggests that maintaining serum 25(OH)D ≥ 30 ng/ml supports bone density and may modestly reduce hot flashes, mood swings, and joint pain. However, the evidence for non-skeletal benefits is moderate at best – RCTs show mixed results. Vitamin D also interacts with calcium, magnesium, and vitamin K2; high-dose D without cofactors can be ineffective or even harmful. Toxicity risk exists above 100 ng/ml. A blood test before supplementation is recommended. Genetic variants in the VDR receptor (e.g., rs2228570) may influence individual response, but clinical utility is limited. In summary, vitamin D is a key player in menopausal bone health, but it is not a standalone solution. A holistic approach including diet, exercise, and possibly hormone therapy is warranted. Avoid megadoses and check levels periodically.