Multivitamins, vitamin D, B12, vitamin C, antioxidant risk, cognition and longevity — separating deficiency correction from wishful thinking.
The largest recent US analysis found no mortality advantage for daily multivitamin users. That does not make deficiency treatment pointless — it changes the question.
Read article Swedish twins show that the balance between genes and environment shifts with the season. A randomized twin trial shows supplementation can change biology — without proving longevity.
Read article A British twin study found a strong heritable component to a combined B12-status measure, reminding us that intake and biological status are not the same thing.
Read article A double-blind study of 95 identical twin pairs found no general prevention effect on colds — and a fascinating lesson about how subgroup results can mislead.
Read article Vitamin E increased prostate-cancer risk in SELECT. Beta-carotene plus retinol increased lung cancer and mortality in high-risk CARET participants. 'Antioxidant' never meant 'risk-free'.
Read article Classic twins put lifespan heritability near one quarter. New modelling of intrinsic mortality argues for a larger genetic component. Neither gives anyone a genetic expiry date.
Read article COSMOS found modest benefits for global cognition and memory in older adults, with an effect size researchers compared with roughly two years of cognitive ageing. That is not dementia prevention.
Read article Vitamin D, B12 and homocysteine twin studies show that biological status varies for genetic and environmental reasons. Personalized nutrition should mean better questions, not bigger supplement stacks.
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