Related Experiment Video
Updated: May 21, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
[Vitamin D metabolism]
1Ústav lékarské chemie a biochemie, Lékarské fakulty UK Plzen. Vlastimil.Kulda@lfp.cuni.cz
Abstract:
Vitamin D is the collective name for cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2), which are precursors of hormones with an important role in regulation of the metabolism of calcium and phosphates. This review article describes the production of vitamin D3 in the skin by ultraviolet radiation from sunlight, transport of vitamin D and its metabolites in blood, formation of the active hormonal form - calcitriol (1,25-dihydroxyvitamin D) by hydroxylation in the liver and kidney, and termination of the action by catabolism to inactive metabolites.
Related Concept Videos
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism
Regulation of Metabolism
What is Metabolism?
Drug Metabolism: Phase II Reactions
