Risks and limits of Vitamin D Männer

The risks and limits of vitamin D in men are well established. Excessive intake (usually from high-dose supplements) can cause hypercalcemia, leading to kidney stones, vascular calcification, and cardiac arrhythmias. The tolerable upper intake level (UL) is 100 µg (4000 IU) per day according to the IOM, though the Endocrine Society allows higher doses under medical supervision for at-risk groups. Long-term trials show no clear benefit for cardiovascular or cancer outcomes when serum levels exceed 50 nmol/l. In men, there is a possible but unconfirmed link between very high vitamin D levels and increased prostate cancer risk. Evidence for personalized vitamin D recommendations based on genetic tests (e.g., VDR variants) is weak; the utility of such tests remains unclear. Importantly, a blood test (25(OH)D) is the only reliable way to assess status. High-dose supplementation should not be undertaken without medical advice. The limits include insufficient evidence for many claimed benefits and high inter-individual variability in vitamin D metabolism.