DOI: 10.11118/978-80-7701-100-6-0217

SUPLEMENTACE POPULACE VITAMINEM D A JEHO TOXICITA

VITAMIN D SUPPLEMENTATION OF THE POPULATION AND ITS TOXICITY

Radek Kučera^1,2, Michal Jirásko^1,2, Hedvika Hatáková^1,2

¹ Ústav farmakologie a toxikologie, Univerzita Karlova, Lékařská fakulta v Plzni, Alej Svobody 76, 323 00 Plzeň, Česká republika

² Oddělení imunochemické diagnostiky, Fakultní nemocnice Plzeň, Edvarda Beneše 1128/13, 305 99 Plzeň, Česká republika

Vitamin D supplementation is an effective way to address its deficiency. The success of supplementation can be monitored by measuring the concentration of the storage form 25(OH)D, from which active calcitriol is formed as needed. In the case of excessive vitamin D intake, calcidiol is metabolized to inactive 24,25(OH)₂D by 24-hydroxylase, thus preventing the development of hypercalcemia and hormonal imbalance. The study included 65 volunteers supplemented with cholecalciferol in doses of 1,000–8,000 IU per day in two seasons. The levels of 25(OH)D and 24,25(OH)₂D showed dose-dependent changes, and no limitation of 24-hydroxylase activity was observed even at the highest dose. A positive correlation of vitamin D with calcium, a weaker one with phosphorus, and a slight inverse relationship with magnesium and parathyroid hormone were found. The results provide new insights into the regulation of vitamin D metabolism and its relationships to minerals and parathyroid hormone.

Keywords: vitamin D, supplementation, toxicity

pages: 217-219, online: 2026