Cholecalciferol, also known as vitamin D
3 and colecalciferol, is a type of
vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
that is made by the skin when exposed to sunlight; it is found in some foods and can be taken as a
dietary supplement.
Cholecalciferol is made in the skin following
UVB light exposure.
It is converted in the liver to
calcifediol
Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 (abbreviated 25(OH)D3), is a form of vitamin D produced in the liver by hydroxylation of vitamin D3 (cholecalciferol) by the enzyme vitamin D 25-hydroxylas ...
(25-hydroxyvitamin D) which is then converted in the kidney to
calcitriol
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the ...
(1,25-dihydroxyvitamin D).
One of its actions is to increase
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
uptake by the intestines.
It is found in food such as some
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...
, beef liver, eggs, and cheese.
Plant and cow milk, fruit juice, yogurt, and margarine also may have cholecalciferol added to them in some countries, including the United States.
[
Cholecalciferol can be taken as an oral dietary supplement to prevent ]vitamin D deficiency
Vitamin D deficiency or hypovitaminosis D is a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate exposure to sunlight, particularly sunlight with adequate ultraviolet B rays (UVB). Vitamin D defic ...
or as a medication to treat associated diseases, including rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications ma ...
. It is also used for familial hypophosphatemia
X-linked hypophosphatemia (XLH) is an X-linked dominant form of rickets (or osteomalacia) that differs from most cases of dietary deficiency rickets in that vitamin D supplementation does not cure it. It can cause bone deformity including short st ...
, hypoparathyroidism
Hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone (PTH). This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany (involuntary m ...
that is causing low blood calcium, and Fanconi syndrome
Fanconi syndrome or Fanconi's syndrome (, ) is a syndrome of inadequate reabsorption in the proximal renal tubules of the kidney. The syndrome can be caused by various underlying congenital or acquired diseases, by toxicity (for example, from tox ...
. Vitamin-D supplements may not be effective in people with severe kidney disease.[ Excessive doses in humans can result in vomiting, constipation, weakness, and confusion.][ Other risks include ]kidney stones
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a calculus (medicine), solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the ...
.[ Doses greater than 40,000 IU (1,000μg) per day are generally required before ]high blood calcium
Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalcemi ...
occurs. Normal doses, 800–2000 IU per day, are safe in pregnancy
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
.[
Cholecalciferol was first described in 1936.] It is on the World Health Organization's List of Essential Medicines
The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...
. In 2020, it was the 60th most commonly prescribed medication in the United States, with more than 11million prescriptions. Cholecalciferol is available as a generic medication and over the counter
Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid prescr ...
.
Medical uses
Cholecalciferol appears to stimulate the body's interferon type I
The type-I interferons (IFN) are cytokines which play essential roles in inflammation, immunoregulation, tumor cells recognition, and T-cell responses. In the human genome, a cluster of thirteen functional IFN genes is located at the 9p21.3 cyt ...
signaling system that protects against bacteria and viruses, unlike Vitamin D2
Ergocalciferol, also known as vitamin D2 and nonspecifically calciferol, is a type of vitamin D found in food and used as a dietary supplement. As a supplement it is used to prevent and treat vitamin D deficiency. This includes vitamin D defici ...
.
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
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the ...
. This is important for maintaining calcium levels and promoting bone health and development.[ As a medication, cholecalciferol may be taken as a dietary supplement to prevent or to treat vitamin D deficiency. One gram is 40,000,000 (40x106) IU, equivalently 1 IU is 0.025 μg or 25 ng. Dietary reference intake values for vitamin D (cholecalciferol and/or ergocalciferol) have been established and recommendations vary depending on the country:
*In the US: 15 μg/d (600 IU per day) for all individuals (males, females, pregnant/lactating women) between the ages of 1 and 70 years old, inclusive. For all individuals older than 70 years, 20 μg/d (800 IU per day) is recommended.][DRIs for Calcium and Vitamin D](_blank)
*In the EU (except France): 20 μg/d (800 IU per day)
*In France: 25 μg/d (1000 IU per day)
Low levels of vitamin D are more commonly found in individuals living in northern latitudes, or with other reasons for a lack of regular sun exposure, including being housebound, frail, elderly, obese, having darker skin, or wearing clothes that cover most of the skin. Supplements are recommended for these groups of people.
The Institute of Medicine in 2010 recommended a maximum uptake of vitamin D of 4,000 IU/day, finding that the dose for lowest observed adverse effect level is 40,000 IU daily for at least 12 weeks, and that there was a single case of toxicity above 10,000 IU after more than 7 years of daily intake; this case of toxicity occurred in circumstances that have led other researchers to dispute it as a credible case to consider when making vitamin D intake recommendations. Patients with severe vitamin D deficiency will require treatment with a loading dose
In pharmacokinetics, a loading dose is an initial higher dose of a drug that may be given at the beginning of a course of treatment before dropping down to a lower maintenance dose.
A loading dose is most useful for drugs that are eliminated fro ...
; its magnitude can be calculated based on the actual serum 25-hydroxy-vitamin D level and body weight.
There are conflicting reports concerning the relative effectiveness of cholecalciferol (D3) versus ergocalciferol
Ergocalciferol, also known as vitamin D2 and nonspecifically calciferol, is a type of vitamin D found in food and used as a dietary supplement. As a supplement it is used to prevent and treat vitamin D deficiency. This includes vitamin D defici ...
(D2), with some studies suggesting less efficacy of D2, and others showing no difference. There are differences in absorption, binding and inactivation of the two forms, with evidence usually favoring cholecalciferol in raising levels in blood, although more research is needed.
A much less common use of cholecalciferol therapy in rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications ma ...
utilizes a single large dose and has been called ''stoss'' therapy. Treatment is given either orally or by intramuscular injection of 300,000 IU (7,500 μg) to 500,000 IU (12,500 μg = 12.5 mg), in a single dose, or sometimes in two to four divided doses. There are concerns about the safety of such large doses.
Low circulating vitamin D levels have been associated with lower total testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...
levels in males. There has been shown information that Vitamin D supplmentation could potentially have evidence on total testosterone concentration
Total may refer to:
Mathematics
* Total, the summation of a set of numbers
* Total order, a partial order without incomparable pairs
* Total relation, which may also mean
** connected relation (a binary relation in which any two elements are com ...
, although more research is needed.
Other diseases
A meta-analysis of 2007 concluded that daily intake of 1000 to 2000 IU per day of vitamin D3 could reduce the incidence of colorectal cancer with minimal risk. Also a 2008 study published in Cancer Research has shown the addition of vitamin D3 (along with calcium) to the diet of some mice fed a regimen similar in nutritional content to a new Western diet with 1000 IU cholecalciferol per day prevented colon cancer development. In humans, with 400 IU daily, there was no effect of cholecalciferol supplements on the risk of colorectal cancer.
Supplements are not recommended for prevention of cancer as any effects of cholecalciferol are very small. Although correlations exist between low levels of blood serum cholecalciferol and higher rates of various cancers, multiple sclerosis, tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, i ...
, heart disease, and diabetes, the consensus is that supplementing levels is not beneficial. It is thought that tuberculosis may result in lower levels. It, however, is not entirely clear how the two are related.
Biochemistry
Structure
Cholecalciferol is one of the five forms of vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
. Cholecalciferol is a secosteroid
A secosteroid () is a type of steroid with a "broken" ring. The word ''secosteroid ''derives from the Latin verb ''secare'' meaning "to cut", and 'steroid'. Secosteroids are alternatively described as a subclass of steroids; ; or derived from s ...
, that is, a steroid molecule with one ring open.
Mechanism of action
By itself cholecalciferol is inactive. It is converted to its active form by two hydroxylations: the first in the liver, by CYP2R1
CYP2R1 is cytochrome P450 2R1, an enzyme which is the principal vitamin D 25-hydroxylase. In humans it is encoded by the ''CYP2R1'' gene located on chromosome 11p15.2. It is expressed in the endoplasmic reticulum in liver, where it performs the fi ...
or CYP27A1, to form 25-hydroxycholecalciferol (calcifediol
Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 (abbreviated 25(OH)D3), is a form of vitamin D produced in the liver by hydroxylation of vitamin D3 (cholecalciferol) by the enzyme vitamin D 25-hydroxylas ...
, 25-OH vitamin D3). The second hydroxylation occurs mainly in the kidney through the action of CYP27B1
25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the ''CYP27B1'' gene.
...
to convert 25-OH vitamin D3 into 1,25-dihydroxycholecalciferol (calcitriol
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the ...
, 1,25-(OH)2vitamin D3). All these metabolites are bound in blood to the vitamin D-binding protein
Vitamin D-binding protein (DBP), also/originally known as gc-globulin (group-specific component), is a protein that in humans is encoded by the ''GC'' gene. DBP is genetically the oldest member of the albuminoid family and appeared early in the e ...
. The action of calcitriol is mediated by the vitamin D receptor
The vitamin D receptor (VDR also known as the calcitriol receptor) is a member of the nuclear receptor family of transcription factors. Calcitriol (the active form of vitamin D, 1,25-(OH)2vitamin D3) binds to VDR, which then forms a heterodim ...
, a nuclear receptor which regulates the synthesis of hundreds of proteins and is present in virtually every cell in the body.[
]
Biosynthesis
Click on icon in lower right corner to open.
7-Dehydrocholesterol is the precursor of cholecalciferol.[ Within the epidermal layer of skin, 7-dehydrocholesterol undergoes an ]electrocyclic reaction In organic chemistry, an electrocyclic reaction is a type of pericyclic rearrangement where the net result is one pi bond being converted into one sigma bond or vice versa. These reactions are usually categorized by the following criteria:
* Reac ...
as a result of UVB light at wavelengths
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...
between 290 and 315 nm, with peak synthesis occurring between 295 and 300 nm. This results in the opening of the vitamin precursor B-ring through a conrotatory
An electrocyclic reaction can either be classified as conrotatory or disrotatory based on the rotation at each end of the molecule. In conrotatory mode, both atomic orbitals of the end groups turn in the same direction (such as both atomic orbital ...
pathway making previtamin D3 (pre-cholecalciferol). In a process which is independent of UV light, the pre-cholecalciferol then undergoes a ,7antarafacial sigmatropic
A sigmatropic reaction in organic chemistry is a pericyclic reaction wherein the net result is one σ-bond is changed to another σ-bond in an uncatalyzed intramolecular reaction. The name ''sigmatropic'' is the result of a compounding of the long ...
rearrangement and therein finally isomerizes to form vitamin D3.
The active UVB wavelengths are present in sunlight, and sufficient amounts of cholecalciferol can be produced with moderate exposure of the skin, depending on the strength of the sun. Time of day, season, and altitude affect the strength of the sun, and pollution, cloud cover or glass all reduce the amount of UVB exposure. Exposure of face, arms and legs, averaging 5–30 minutes twice per week, may be sufficient, but the darker the skin, and the weaker the sunlight, the more minutes of exposure are needed. Vitamin D overdose is impossible from UV exposure; the skin reaches an equilibrium where the vitamin degrades as fast as it is created.
Cholecalciferol can be produced in skin from the light emitted by the UV lamps in tanning bed
Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ho ...
s, which produce ultraviolet primarily in the UVA spectrum, but typically produce 4% to 10% of the total UV emissions as UVB. Levels in blood are higher in frequent uses of tanning salons.
Whether cholecalciferol and all forms of vitamin D are by definition "vitamins
A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrien ...
" can be disputed, since the definition of vitamins includes that the substance cannot be synthesized by the body and must be ingested. Cholecalciferol ''is'' synthesized by the body during UVB radiation exposure.[
The three steps in the synthesis and activation of vitamin D3 are regulated as follows:
* Cholecalciferol is synthesized in the skin from 7-dehydrocholesterol under the action of ultraviolet B (UVB) light. It reaches an equilibrium after several minutes depending on the intensity of the UVB in the sunlight – determined by latitude, season, cloud cover, and altitude – and the age and degree of pigmentation of the skin.
* Hydroxylation in the endoplasmic reticulum of liver ]hepatocyte
A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass.
These cells are involved in:
* Protein synthesis
* Protein storage
* Transformation of carbohydrates
* Synthesis of cholesterol, ...
s of cholecalciferol to calcifediol (25-hydroxycholecalciferol) by 25-hydroxylase is loosely regulated, if at all, and blood levels of this molecule largely reflect the amount of cholecalciferol produced in the skin combined with any vitamin D2 or D3 ingested.
* Hydroxylation in the kidneys of calcifediol to calcitriol by 1-alpha-hydroxylase is tightly regulated: it is stimulated by parathyroid hormone
Parathyroid hormone (PTH), also called parathormone or parathyrin, is a peptide hormone secreted by the parathyroid glands that regulates the serum calcium concentration through its effects on bone, kidney, and intestine.
PTH influences bone ...
and serves as the major control point in the production of the active circulating hormone calcitriol
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the ...
(1,25-dihydroxyvitamin D3).[
]
Industrial production
Cholecalciferol is produced industrially for use in vitamin supplement
A multivitamin is a preparation intended to serve as a dietary supplement with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, or injectab ...
s and to fortify foods. As a pharmaceutical drug
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field an ...
it is called cholecalciferol (USAN
280px, "Samguk Sagi" Book 04. Silla's Records. In 512, Usan-guk(于山國)was Ulleungdo(鬱陵島)
Usan-guk, or the State of Usan, occupied Ulleung-do and the adjacent islands during the Korean Three Kingdoms period. According to th ...
) or colecalciferol (INN
Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...
, BAN). It is produced by the ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation ...
irradiation of 7-dehydrocholesterol extracted from lanolin
Lanolin (from Latin 'wool', and 'oil'), also called wool yolk, wool wax, or wool grease, is a wax secreted by the sebaceous gland
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an ...
found in sheep's wool
Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. ...
.[Vitamin D3 Story.](_blank)
Retrieved 8 April 2012. Cholesterol is extracted from wool grease and wool wax alcohols obtained from the cleaning of wool after shearing. The cholesterol undergoes a four-step process to make 7-dehydrocholesterol, the same compound that is produced in the skin of animals. The 7-dehydrocholesterol is then irradiated with ultraviolet light. Some unwanted isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
...
are formed during irradiation: these are removed by various techniques, leaving a resin which melts at about room temperature and usually has a potency of 25,000,000 to 30,000,000 International Units per gram.
Cholecalciferol is also produced industrially for use in vitamin supplements from lichens, which is suitable for vegans.
Stability
Cholecalciferol is very sensitive to UV radiation
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
and will rapidly, but reversibly, break down to form supra-sterols, which can further irreversibly convert to ergosterol.
Pesticide
Rodents are somewhat more susceptible to high doses than other species, and cholecalciferol has been used in poison bait for the control of these pests.[
The mechanism of high dose cholecalciferol is that it can produce " hypercalcemia, which results in systemic calcification of soft tissue, leading to ]kidney failure
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...
, cardiac
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
abnormalities, hypertension, CNS depression, and GI upset. Signs generally develop within 18-36 hr of ingestion and can include depression, loss of appetite
Anorexia is a medical term for a loss of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others i ...
, polyuria
Polyuria () is excessive or an abnormally large production or passage of urine (greater than 2.5 L or 3 L over 24 hours in adults). Increased production and passage of urine may also be termed diuresis. Polyuria often appears in conjunction wit ...
, and polydipsia
Polydipsia is excessive thirst or excess drinking.Porth, C. M. (1990). ''Pathophysiology: Concepts of altered health states''. Philadelphia: J.B. Lippincott Company. The word derives from the Greek () "very thirsty", which is derived from (, "mu ...
."[ High-dose cholecalciferol will tend to rapidly accumulate in ]adipose
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...
tissue yet release more slowly which will tend to delay time of death for several days from the time that high-dose bait is introduced.[
In ]New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, possums
Possum may refer to:
Animals
* Phalangeriformes, or possums, any of a number of arboreal marsupial species native to Australia, New Guinea, and Sulawesi
** Common brushtail possum (''Trichosurus vulpecula''), a common possum in Australian urban a ...
have become a significant pest animal. For possum control, cholecalciferol has been used as the active ingredient in lethal baits. The LD50 is 16.8 mg/kg, but only 9.8 mg/kg if calcium carbonate is added to the bait. Kidneys and heart are target organs. LD50 of 4.4 mg/kg has been reported in rabbits, with lethality to almost all rabbits ingesting doses greater than 15 mg/kg.[R. J. Henderson and C. T. Eason (2000)]
Acute toxicity of cholecalciferol and gliftor baits to the European rabbit, Oryctolagus cuniculus
Wildlife Research 27(3) 297-300. Toxicity has been reported across a wide range of cholecalciferol dosages, with LD50 as high as 88 mg/kg or as low as 2 mcg
The Melbourne Cricket Ground (MCG), also known locally as "The 'G", is an Australian sports stadium located in Yarra Park, Melbourne, Victoria. Founded and managed by the Melbourne Cricket Club, it is the largest stadium in the Southern Hem ...
/kg reported for dogs.[Michael E.Peterson & Kerstin Fluegeman]
Cholecalciferol (Topic Review)
Topics in Companion Animal Medicine, Volume 28, Issue 1, February 2013, Pages 24-27.
Researchers have reported that the compound is less toxic to non-target species than earlier generations of anticoagulant rodenticides (Warfarin
Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent st ...
and congeners) or Bromethalin
Bromethalin is a neurotoxic rodenticide that damages the central nervous system.
History
Bromethalin was discovered in the early 1980s through an approach to find replacement rodenticides for first-generation anticoagulants, especially to be usef ...
, and that relay toxicosis (poisoning by eating a poisoned animal) has not been documented. Nevertheless, the same source reports that use of cholecalciferol in rodenticide
Rodenticides are chemicals made and sold for the purpose of killing rodents. While commonly referred to as "rat poison", rodenticides are also used to kill mice, squirrels, woodchucks, chipmunks, porcupines, nutria, beavers, and voles. Despi ...
s may still pose a significant hazard to other animals, such as dogs and cats, when rodenticide bait or other forms of cholecalciferol are directly ingested.[
]
See also
* Hypervitaminosis D
Vitamin D toxicity, or hypervitaminosis D is the toxic state of an excess of vitamin D. The normal range for blood concentration is 20 to 50 nanograms per milliliter (ng/mL). However, the toxic state is known to be a value of 100 ng/ml or more in ...
, Vitamin D poisoning
* Ergocalciferol
Ergocalciferol, also known as vitamin D2 and nonspecifically calciferol, is a type of vitamin D found in food and used as a dietary supplement. As a supplement it is used to prevent and treat vitamin D deficiency. This includes vitamin D defici ...
, vitamin D2.
* 25-Hydroxyvitamin D3 1-alpha-Hydroxylase
25-Hydroxyvitamin D 1-alpha-hydroxylase (VD 1A hydroxylase) also known as calcidiol 1-monooxygenase or cytochrome p450 27B1 (CYP27B1) or simply 1-alpha-hydroxylase is a cytochrome P450 enzyme that in humans is encoded by the ''CYP27B1'' gene.
...
, a kidney enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that converts calcifediol to calcitriol.
References
LED lights safer, more effective in producing Vitamin D3 than sunlight
External links
NIST Chemistry WebBook page for cholecalciferol
Vitamin D metabolism, sex hormones, and male reproductive function.
*
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