Evidence check: Vitamin D 25-OH in the context of Langlebigkeit

The evidence for vitamin D (25-OH) in the context of longevity is mixed. Observational studies consistently link low 25-hydroxyvitamin D levels with higher all-cause mortality, especially in older adults. However, randomized controlled trials (RCTs) of vitamin D supplementation have not shown a clear benefit for extending lifespan. The VITAL trial (2019) found no significant reduction in total mortality with vitamin D3 (2000 IU/day) in generally healthy adults. Some subgroup analyses suggest potential benefits for those with very low baseline levels (<30 nmol/L), but this remains inconclusive. Additionally, measuring 25-OH vitamin D as a single biomarker for longevity is insufficient; there are no standardized cutoffs for 'optimal' levels regarding life extension. Correcting a deficiency (target >50 nmol/L) is prudent, but supplementing beyond sufficiency is not evidence-based. Caveat: MyBody-X tests are not diagnostic; consult a physician for abnormal results. Evidence grade: human-moderate (observational) to mixed (RCTs).