Vitamin D Deficiency Rises in Germany as Winter Nears

Overview

• A recent Nature Communications analysis found low vitamin D levels increased from about 31% before the pandemic to over 35% during it, while RKI data indicate roughly 15% of adults meet criteria for severe deficiency and DGE estimates over 60% do not achieve sufficient intake.
• At Germany’s latitude, meaningful skin production occurs mainly from March to October, winter UV‑B is often inadequate, and sunscreen on exposed areas substantially reduces cutaneous synthesis.
• Most people obtain only about 2–4 micrograms per day from food versus the roughly 20 micrograms regarded as sufficient, so many will need sensible sun exposure or supplementation to maintain status.
• Experts favor daily supplementation to keep blood levels steady, with DGE recommending 20 micrograms (≈800 IU) and EFSA setting a tolerable upper intake of 4000 IU; higher or intermittent regimens should be guided by a physician.
• Toxicity does not result from sunlight or normal diets but from excessive supplements or fortified products, can trigger hypercalcemia with kidney damage risk, and because 25‑OH‑D clears slowly (half‑life ~10–40 days) normalization may take weeks to months.