Overview
- Late September guidance from German health bodies reconfirms that from October sunlight in Germany generally cannot produce enough vitamin D for most people, so other measures are needed for winter.
- The body supplies about 80–90% of vitamin D through skin production in summer and stores it in fat and muscle, but those summer stores typically last only about two months into the darker months.
- Officials single out higher‑risk groups who should be offered supplements or monitoring: infants (who routinely get prophylactic drops), older people, care‑home residents, people who stay indoors, those who cover their skin for cultural or medical reasons and people with darker skin.
- Experts advise measuring blood levels to guide treatment, aim for levels above roughly 50 nmol/L, avoid unsupervised high‑dose regimens (many experts limit self‑use to 2,000 IU/day) and note chronic oral intake above about 100 µg/day risks toxicity.
- Practical prevention focuses on short regular unprotected sun exposure for face, hands and arms, eating vitamin‑D rich foods like fatty fish and eggs, avoiding solaria because of skin‑cancer risk, and watching fortified products to prevent hidden excess intake.