A fundamental misunderstanding surrounds vitamin D supplementation: the assumption that doubling the dose will double serum levels. Recent controlled research from the American Journal of Clinical Nutrition dispels this myth with striking data.
When researchers administered three escalating doses of vitamin D3 to healthy men during winter months, they observed a decidedly non-linear response. A tenfold increase in supplemental dose produced only 2.8 times the expected serum level increase. This counterintuitive finding stems from the body’s sophisticated active regulation mechanisms.
Vitamin D is not passively accumulated in the bloodstream. Instead, the body tightly controls circulating levels through hepatic hydroxylation, binding protein saturation, and metabolic clearance. These homeostatic processes become increasingly efficient at higher serum concentrations, creating a physiological ceiling effect. Understanding this dose-response curve is essential for evidence-based supplementation strategies.
Read the full article on GMJ Newsroom.
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