Cholecalciferol

vitamin D 3 vitamin D3colecalciferolD3Vigantolused as a rodenticideVitamin D
Cholecalciferol, also known as vitamin D 3 and colecalciferol, is a type of vitamin D which is made by the skin when exposed to sunlight; it is also found in some foods and can be taken as a dietary supplement.wikipedia
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Vitamin D

DCalciferol1,25 Dihydroxy vitamin D
Cholecalciferol, also known as vitamin D 3 and colecalciferol, is a type of vitamin D which is made by the skin when exposed to sunlight; it is also found in some foods and can be taken as a dietary supplement.
In humans, the most important compounds in this group are vitamin D 3 (also known as cholecalciferol) and vitamin D 2 (ergocalciferol).

Calcifediol

calcidiol25-hydroxyvitamin D25-hydroxycholecalciferol
It is converted in the liver to calcifediol (25-hydroxyvitamin D) which is then converted in the kidney to calcitriol (1,25-dihydroxyvitamin D). It is converted to its active form by two hydroxylations: the first in the liver, by CYP2R1 or CYP27A1, to form 25-hydroxycholecalciferol (calcifediol, 25-OH vitamin D 3 ).
Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D (abbreviated 25(OH)D), is a prehormone that is produced in the liver by hydroxylation of vitamin D 3 (cholecalciferol) by the enzyme cholecalciferol 25-hydroxylase.

Vitamin D deficiency

hypovitaminosis Dvitamin Ddeficiency of vitamin D
It is used to treat and prevent vitamin D deficiency and associated diseases, including rickets.
Since vitamin D 3 (also known as cholecalciferol) and vitamin D 2 (ergocalciferol) are fat-soluble, humans and other animals with a skeleton need to store some fat.

Calcitriol

1,25-Dihydroxycholecalciferol1,25 dihydroxyvitamin D 3 1,25-dihydroxyvitamin D 3
It is converted in the liver to calcifediol (25-hydroxyvitamin D) which is then converted in the kidney to calcitriol (1,25-dihydroxyvitamin D).
Compared to other vitamin D compounds in clinical use (cholecalciferol, ergocalciferol), calcitriol has a higher risk of inducing hypercalcemia.

Rickets

rachitisrachiticantirachitic
It is used to treat and prevent vitamin D deficiency and associated diseases, including rickets.
Vitamin D 3 (cholecalciferol) is the preferred form since it is more readily absorbed than vitamin D 2.

Rodenticide

rat poisonrodenticidesanticoagulant rat poison
Cholecalciferol is also used to kill rodents.
Cholecalciferol (vitamin D 3 ) and ergocalciferol (vitamin D 2 ) are used as rodenticides.

Previtamin D3

Previtamin D 3 previtaminD 3
This results in the opening of the vitamin precursor B-ring through a conrotatory pathway making previtamin D3 (pre-cholecalciferol).
Previtamin D 3 is an intermediate in the production of cholecalciferol (vitamin D 3 ).

CYP2R1

vitamin D 25-hydroxylasecholecalciferol 25-hydroxylase
It is converted to its active form by two hydroxylations: the first in the liver, by CYP2R1 or CYP27A1, to form 25-hydroxycholecalciferol (calcifediol, 25-OH vitamin D 3 ).
The gene product which it encodes, vitamin D 25-hydroxylase, has therefore been proposed as the key enzyme in the conversion of cholecalciferol (vitamin D 3 ) to calcidiol.

Ergocalciferol

vitamin D 2 D2ergocalciferols
There are conflicting reports concerning the relative effectiveness of cholecalciferol (D 3 ) versus ergocalciferol (D 2 ), with some studies suggesting less efficacy of D 2, and others showing no difference.
Ergocalciferol may be used as a vitamin D supplement, whereas cholecalciferol (vitamin D 3 ) is produced naturally by the skin when exposed to ultraviolet light.

Secosteroid

secosteroids
Cholecalciferol is a secosteroid, that is, a steroid molecule with one ring open.
The prototypical secosteroid is cholecalciferol (vitamin D 3 ).

Calcitriol receptor

vitamin D receptorVDRvitamin D receptors
The action of calcitriol is mediated by the vitamin D receptor, a nuclear receptor which regulates the synthesis of hundreds of proteins and is present in virtually every cell in the body.
The VDR gene encodes the nuclear hormone receptor for vitamin D 3.

Electrocyclic reaction

electrocyclicelectrocyclizationelectrocyclic ring-opening
Within the epidermal layer of skin, 7-dehydrocholesterol undergoes an electrocyclic reaction as a result of UVB light at wavelengths between 290 and 315 nm, with peak synthesis occurring between 295 and 300 nm.
One of the most common such electrocyclizations is the biosynthesis of vitamin D 3.

Vitamin D-binding protein

GCGC (gene)reaction in humans
All these metabolites are bound in blood to the vitamin D-binding protein.
It is able to bind the various forms of vitamin D including ergocalciferol (vitamin D 2 ) and cholecalciferol (vitamin D 3 ), the 25-hydroxylated forms (calcifediol), and the active hormonal product, 1,25-dihydroxyvitamin D (calcitriol).

Vitamin

vitaminsfat-soluble vitaminsfat-soluble vitamin
Whether cholecalciferol and all forms of vitamin D are by definition "vitamins" can be disputed, since the definition of vitamins includes that the substance cannot be synthesized by the body and must be ingested.

Multivitamin

vitamin supplementmultivitaminsvitamin supplements
Cholecalciferol is produced industrially for use in vitamin supplements and to fortify foods.
Many multivitamin formulas contain vitamin C, B1, B2, B3, B5, B6, B7, B9, B12, A, E, D2 (or D3), K, potassium, iodine, selenium, borate, zinc, calcium, magnesium, manganese, molybdenum, beta carotene, and/or iron.

7-Dehydrocholesterol

7DHC
7-Dehydrocholesterol is the precursor of cholecalciferol. It is produced by the ultraviolet irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool.
7-Dehydrocholesterol (7-DHC) is a zoosterol that functions in the serum as a cholesterol precursor, and is photochemically converted to vitamin D 3 in the skin, therefore functioning as provitamin-D 3.

WHO Model List of Essential Medicines

World Health Organization's List of Essential MedicinesList of Essential MedicinesModel List of Essential Medicines
It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.

Indoor tanning

tanning bedtanning salontanning booth
Cholecalciferol can be produced in skin from the light emitted by the UV lamps in tanning beds, which produce ultraviolet primarily in the UVA spectrum, but typically produce 4% to 10% of the total UV emissions as UVB.
Exposing arms and legs to a minimal 0.5 erythemal (mild sunburn) UVB dose is equal to consuming about 3000 IU of vitamin D3.

Lanolin

EuceritE913grease
It is produced by the ultraviolet irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool.
7-Dehydrocholesterol from lanolin is used as a raw material for producing vitamin D 3 by irradiation with ultraviolet light.

Hypervitaminosis D

Vitamin D intoxicationvitamin D poisoningvitamin D toxicity
The harm from vitamin D 3 in larger doses is demonstrated in that very high-doses are sometimes used as a rodenticide, where it causes hypercalcemia leading to death, typically only after several days following the high dose.

Median lethal dose

LD50LD 50 LC50
The LD 50 is 16.8 mg/kg, but only 9.8 mg/kg if calcium carbonate is added to the bait.

Ultraviolet

UVultraviolet lightultraviolet radiation
Within the epidermal layer of skin, 7-dehydrocholesterol undergoes an electrocyclic reaction as a result of UVB light at wavelengths between 290 and 315 nm, with peak synthesis occurring between 295 and 300 nm. Cholecalciferol can be produced in skin from the light emitted by the UV lamps in tanning beds, which produce ultraviolet primarily in the UVA spectrum, but typically produce 4% to 10% of the total UV emissions as UVB. It is produced by the ultraviolet irradiation of 7-dehydrocholesterol extracted from lanolin found in sheep's wool. Cholecalciferol is made in the skin following UVB light exposure.
Specifically cholecalciferol (vitamin D3), which is needed to for basic cellular / neural functioning as well as the utilization calcium for bone and egg production.

Hypercalcaemia

hypercalcemiahigh blood calciumhigh blood calcium levels
The mechanism of high dose cholecalciferol is that it can produce "hypercalcemia, which results in systemic calcification of soft tissue, leading to renal failure, cardiac abnormalities, hypertension, CNS depression, and GI upset. Signs generally develop within 18-36 hr of ingestion and can include depression, loss of appetite, polyuria, and polydipsia."
Plants such as Cestrum diurnum, and Solanum malacoxylon contain ergocalciferol or cholecalciferol which cause the onset of hypercalcemia.

Dietary supplement

dietary supplementsnutritional supplementnutritional supplements
Cholecalciferol, also known as vitamin D 3 and colecalciferol, is a type of vitamin D which is made by the skin when exposed to sunlight; it is also found in some foods and can be taken as a dietary supplement.

X-linked hypophosphatemia

Hypophosphatemic ricketsX-linked hypophosphatemic ricketsfamilial hypophosphatemia
It is also used for familial hypophosphatemia, hypoparathyroidism that is causing low blood calcium, and Fanconi syndrome.