Search results
Results from the WOW.Com Content Network
CYP2R1 is cytochrome P450 2R1, an enzyme which is the principal vitamin D 25-hydroxylase. [5] [6] In humans it is encoded by the CYP2R1 gene located on chromosome 11p15.2. [7]It is expressed in the endoplasmic reticulum in liver, where it performs the first step in the activation of vitamin D by catalyzing the formation of 25-hydroxyvitamin D. [8]
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. [1][2] In humans, the most significant compounds within this group are vitamin D 3 (cholecalciferol) and vitamin D 2 (ergocalciferol). [2][3]
Vitamin D deficiency is typically diagnosed by measuring the concentration of the 25-hydroxyvitamin D in the blood, which is the most accurate measure of stores of vitamin D in the body. [1][7][2] One nanogram per millilitre (1 ng/mL) is equivalent to 2.5 nanomoles per litre (2.5 nmol/L). Severe deficiency: <12 ng/mL = <30 nmol/L[2] Deficiency ...
These modified vitamin D analogues have a side chain or other modifications. They aim to reduce the classical renal and intestinal effects of calcitriol on calcium and phosphate homeostasis, from its effects on other biologic processes. [5] They target cell proliferation and differentiation, especially in skin, or other effects in the ...
Ergocalciferol, also known as vitamin D2 and nonspecifically calciferol, is a type of vitamin D found in food and used as a dietary supplement. [3] As a supplement it is used to prevent and treat vitamin D deficiency. [4] This includes vitamin D deficiency due to poor absorption by the intestines or liver disease. [5]
CYP24A1 is an enzyme expressed in the mitochondrion of humans and other species. It catalyzes hydroxylation reactions which lead to the degradation of 1,25-dihydroxyvitamin D 3, the physiologically active form of vitamin D. Hydroxylation of the side chain produces calcitroic acid and other metabolites which are excreted in bile. [5][6] CYP24A1 ...
Vitamin D deficiency. Cholecalciferol is a form of vitamin D which is naturally synthesized in skin and functions as a pro-hormone, being converted to calcitriol. This is important for maintaining calcium levels and promoting bone health and development. [4] As a medication, cholecalciferol may be taken as a dietary supplement to prevent or to ...
Previtamin D3 is an intermediate in the production of cholecalciferol (vitamin D 3). It is formed by the action of UV light, most specifically UVB light of wavelengths between 295 and 300 nm, acting on 7-dehydrocholesterol in the epidermal layers of the skin. [1][2][3] The B ring of the steroid nucleus structure is broken open, making a ...