Guidance Urges Measured Vitamin D Testing and Doctor‑Led Dosing

Overview

• Coverage on Friday consolidated advice that checking blood 25‑hydroxyvitamin D is the reliable first step and that any supplementation should be planned with a physician based on those results.
• Experts and labs disagree on target ranges, with the Robert Koch Institute citing about 30–50 ng/ml, some specialists recommending 50–70 ng/ml, and some labs flagging levels above 70 ng/ml as excessive; 1 ng/ml equals 2.5 nmol/l.
• Clinicians typically correct low levels with a short course of higher doses (often about a month) and then switch to lower maintenance doses, and tablets and drops are equally effective at raising blood levels.
• Official numeric anchors include the DGE recommendation of 20 µg (800 IU) daily for adults and the EFSA tolerable upper intake of 100 µg (4,000 IU), and the BfR warns that long‑term high‑dose use can cause harm such as high blood calcium, nausea and heart rhythm problems.
• Sunlight is the main source of vitamin D and levels fall in winter, so at‑risk groups (older people, those rarely outdoors, people with dark skin or absorption problems) should be prioritized for testing and advised to take supplements with a fat‑containing meal for better absorption.