Health Authorities Urge Testing Over Routine Vitamin D Supplements

Overview

• Most vitamin D is produced in the skin through sunlight, with effective synthesis in Germany mainly from March to October and higher deficiency risk for people who are rarely outdoors, wear covering clothing, have darker skin, chronic illnesses, or take certain medications.
• Officials advise against preventive pills and recommend supplementation only after a physician confirms deficiency or inadequate improvement through sunlight and diet.
• Recommended daily intakes differ by body: DGE 800 IU, NHS 400 IU, NIH 600 IU, and the Endocrine Society 1,500–2,000 IU, while therapeutic dosing for deficiency is calculated individually from lab values and body weight.
• Because vitamin D is fat‑soluble, tablets should be taken with a fatty meal, drops or capsules can be taken without meals, and the time of day does not affect absorption.
• Safety guidance sets EFSA’s tolerable upper level for adults at 100 µg (about 4,000 IU) and BfR warns against long‑term high doses, with experts urging lab checks before combining D3 with K2 or using around 2,000 IU or more, and caution for those on vitamin‑K‑antagonist anticoagulants.