Overview

• The new guidance endorses personalized serum targets for Vitamin D based on recent telomere research linking optimal levels to slower cellular ageing.
• Statutory health insurers will cover blood tests only for patients with medical indication, leaving asymptomatic individuals to pay €20–35 per test.
• At-risk groups include people with limited sun exposure, darker skin, cultural covering, chronic gastrointestinal, liver or kidney diseases, and those on certain medications.
• Vitamin D deficiency is defined as blood levels below 12 ng/ml (30 nmol/l), while sufficiency falls within an international norm of 20–50 µg/l.
• Recommended daily doses range from 400–600 IU to 1,500–2,000 IU for deficient individuals, with a 4,000 IU upper limit, and supplements should be taken with dietary fat to improve absorption while avoiding chronic overdose risks such as hypercalcemia and kidney stones.