Overview
- Pharmacists and clinicians urge people to check levels first, with vitamin D supplements recommended when blood values are low and dosing tailored to health status and weight.
- Germany’s Robert Koch Institute reports that about 30.2% of adults have insufficient vitamin D, and statutory insurers generally fund a lab test only when a doctor suspects deficiency, with many others paying about €20–30 privately.
- Experts explain that most B vitamins are water‑soluble and excess leaves the body in urine, yet chronic high doses can still harm health, including neuropathy tied to very high vitamin B6 intake and rare liver effects from niacin.
- Regulators at the Federal Institute for Risk Assessment set upper intake levels to cap long‑term supplement doses and, after review, removed those caps for vitamins B1, B2 and B5 because studies did not show adverse effects at high intakes.
- Vitamin B12 is found mainly in animal foods, so vegans are advised to supplement, and clinicians use several markers to assess status, including total serum B12, holotranscobalamin, methylmalonic acid and homocysteine.