Cholecalciferol, or vitamin D3, is an organic chemical that belongs to the family of D vitamins. It is naturally found in fatty fish, fish oil, egg yolks, milk and dairy products. It is also synthesized in the human body. It is formed from 7-dehydrocholesterol present in the keratinocytes of the spinous and the basal layers of the epidermis, and a pre-requisite for initiating this process is the action of 290-315 nm wavelength UVB radiation on the skin.
Cholecalciferol is a biologically inactive compound. In the body, it undergoes enzymatic hydroxylation – first in the liver, with the participation of 25-hydroxylase, when calcidiol is formed and secondly in the kidneys, where under the influence of 1-α-hydroxylase, calcidiol is converted into the final active form – calcitriol.
The most important role of vitamin D3 in the body is the regulation of calcium-phosphate metabolism, which directly affects normal skeletal mineralization. In addition, it is involved in cell proliferation and differentiation, insulin secretion, as well as in some functions of the nervous, endocrine and immune systems.
Cholecalciferol is the most popular form of vitamin D used in dietary supplements. Studies show that supplementation with vitamin D in this form most effectively and rapidly raises the level of 25 (OH) D3 – a metabolite that is a marker of the level of vitamin D in the body.
Dosage: according to RDI standards for individual age groups.