How are Vitamin D 25-OH and Abnehmen related?

The relationship between vitamin D (25-OH) and weight loss is complex and often misunderstood. Vitamin D deficiency is more common in people with obesity, partly because the fat-soluble vitamin gets sequestered in adipose tissue. Low 25-OH levels may impair metabolism and insulin sensitivity, potentially making weight loss harder. Observational studies show an association between low vitamin D and higher body fat, but randomized controlled trials do not demonstrate significant weight loss from vitamin D supplementation alone in replete individuals. The evidence is moderate: plausible mechanisms exist (e.g., effects on leptin, PTH), but strong clinical proof is lacking. A blood test for 25-OH is the gold standard to assess status. If deficiency is confirmed, supplementation can support overall health but is not a substitute for calorie restriction and exercise. Caution: the EFSA upper limit is 4000 IU/day for adults. DNA tests for vitamin D receptor variants are not validated for dosing decisions.