Vitamin D
Vitamin D is steroid derivatives. It is the general term for the compounds that have similar structures and have the effect of normal skeletal growth and maintenance. At present, there are at least more than ten kinds of sterols that have vitamin D activity. But there are only two important matters, which are known as pro-vitamin D. One is ergosterol that exists in vegetable oil or yeast, which can generate vitamin D2 when irradiated by sunlight or ultraviolet radiation. It is also known as cholecalciferol or ergocalciferol. Another is 7-dehydrochlesterol that exists in the skin. It will become vitamin D3 after irradiated by the light. It is also called cholecalciferol. D2 and D3 have similar structures. They are B ring derivatives of precursors of the sterol. The difference is that the side chain of vitamin D2 has a methyl group and one double bond.
Vitamin D2 and D3 are all colorless crystals. The melting point of D2 and D3 respectively are 115~118℃ and 84~85℃. They are insoluble in water, and soluble in ethanol and other organic solvents. Their solubility in vegetable oil are small. Crystalline vitamin D should be stored in dark to light and oxygen at low temperature. Vitamin D3 is more stable than D2. It is not easy to be oxidized. Vitamin D has heat stability in the near neutral solution. It will be rapidly destroyed in the acidic solution, and the rate of destruction depends on strength and temperature of the acid. However, it is stable in alkaline solution. It can tolerate alkali treatment even under high temperature conditions.
In the industrial synthesis products, vitamin D3 is more. Vitamin D3 is sensitive to light and can be damaged by minerals and oxidation. But vitamin D3 has good stability after esterification and coated by gelatin, sugar and starch. The activity of vitamin D3 is also represented by International Units (IU). The amount of IU crystals vitamin D3 is 0.025μg. The active ingredient content of the industrial synthesis of vitamin D3 additive is more of 500,000 IU/g or 200 000 IU/g. For vitamin additives products, there are also additives that contain vitamin A and vitamin D3. The activity is usually 1g additive containing 500,000 IU of vitamin A and 100,000 IU of vitamin D3. The two has no antagonistic effect. And their production and use are very convenient. Vitamin D can increase the absorption and metabolism of calcium and phosphorus, prevent swine rickets, and promote the development of teeth and bones. Vitamin D dosage of pig feed is 125~200IU/kg. The amount for piglets is higher than growing pig. The amount of boar and growing pig are similar.
Physiological function
Under UV irradiation vegetative ergosterol and animal 7-dehydrogenation are absorbed and convert into vitamin D2 and vitamin D3. The two vitamin D must produc further chemical changes before used by the body. 7-dehydrocholesterol first form into 25-hydroxy derivative in the liver, then generate active ingredient 1,25-dihydroxyvitamin cholecalciferol [1,25 (OH) 2D5] by hydroxylation. The main function of vitamin D is to promote intestinal absorption of calcium and phosphorus, and regulate metabolism of calcium and phosphorus in order to maintain the body's calcium and phosphorus balance. Calcium absorbed from intestinal canal can be transported through the blood circulation from the liver and kidneys to the bone and other calcified tissues, and excret from the bone to the kidneys. This transport mechanism is controlled by vitamin D. When the concentration of calcium, phosphorus in the body decreases, vitamin D can dissociate calcium from the bone. In addition, vitamin D can also control kidney tubules to reabsorb calcium and phosphorus.
Vitamin D2 and vitamin D3 has the same function on ammals cows and pigs. But vitamin D3 for poultry (birds) is ten times stronger activity than vitamin D2.
Vitamin D deficiency can reduce the intestinal absorption of calcium, and cause the decomposition of bone calcium and phosphorus. Young livestock will appear osteomalacia. Adult animals are easy to appear osteoporosis. Vitamin D deficiency can also lead to animal sternum and spine deformation and layers laying soft-shell eggs. Because vitamin D controls the absorption of calcium and phosphorus, too much vitamin D in dietary can cause hypercalcemia, make excess calcium deposit in the heart, blood vessels, joints, pericardium or intestinal wall, and finally lead to heart failure, joint stiffness or bowel Road disorders.
Sunbathing is the most economical source of vitamin D. ergosterol or 7-dehydrogenation cholesterol in the feed will turn into vitamin D by ultraviolet radiation inside an animal for the utilization of carcass. Hay, corn leaves yeast, barley, oats, wheat after insolation and yeast after ultraviolet treatment are better sources of vitamin D. Animal products can be directly provide vitamin D to livestock, such as eggs, milk. The content of vitamin D in cod liver oil is very high. Diets need to be added vitamin D for reared animals and insufficient sunlight animal.
The above information is edited by the Chemicalbook of Ge Qian.
Content analysis
Same with “vitamin D2 (01043)”. But all ergocalciferol is replaced by cholecalciferol.
Toxicity
LD50 oral in rat: 42mg/kg
Maximum level
GB 14880-94: same with “01043, vitamin D2”
FDA, §18. 1950(2000): same with “01043, vitamin D2”
Chemical property
White columnar crystals or crystalline powder, odorless and tasteless. Melting point 84~88℃, specific rotation αD20 =+105°~+112°. Easily soluble in chloroform, soluble in alcohol, ether, cyclohexane and acetone, slightly soluble in vegetable oil, insoluble in water. Good heat resistance, but unstable for light. Easily oxidized in air. Rats by oral LD1042mg/kg.
Uses
1. Vitamin D3 can maintain normal metabolism of calcium and phosphorus, promote the body's absorption of calcium and phosphorus. When it is lacked, children are easy to get rickets. Regulations in China provides it can be used to strengthening margarine. The dosage is 125~156μg/kg. The dosage in fortified dairy products is 63~125μg/kg. The dosage in strengthening infant food is 50~100μg/kg. And the dosage in strengthening milk and milk drink is 10~40μg/kg. The largest dosage in the strengthening solid drinks and ice cream is 10~20μg/kg.
2. Vitamin D3 can maintain normal metabolism of calcium and phosphorus and promote the body's absorption of calcium and phosphorus. The utilization of 1. vitamin D2 and D3 for pigs are the same, but the utilization of vitamin D2 for poultry is only 1/40-1/30 of vitamin D3. When lack of Vitamin D3, eggshell will become thin, the rate of laying will decrease, and rickets will appear. The amount can be 1000-1500IU/kg.
3. Vitamin D is a fat-soluble vitamin. There are a dozen compounds that are known to have the effect of vitamin D. Vitamin D2 and vitamin D3 have the important practical significance in no lines steroid derivative. D3 is given priority to with in the world, "International Standards" of vitamin D is pure crystalline D3. The main function of vitamin D are metabolism of calcium, phosphorus. It is difficult to promote the absorption of calcium and phosphorus and the calcification of bone. When the body is lack of vitamin D, the ability to absorb calcium and phosphorus will decrease, and the content of calcium and phosphorus in the blood will reduce. Then calcium and phosphorus cannot be deposited in bone tissue, even bone salt will dissolve and hinder the bone calcification. Children lack of vitamin D will get rickets. Adult lack of vitamin D will get osteomalacia. Japanese like to produce and use D2. In a variety of demand, the amount of pharmaceutical is 30%, feed additives is 65%, and food additives is 5%. According to the "food fortifier use of health standards (1993)" issued by Ministry of Health, D2 and D3, as nutritional supplements, can be used for liquid milk, margarine, dairy products and baby food.
4. Vitamin medicines. It mainly can promote intestinal absorption and deposition of calcium and phosphorus for the treatment of rickets and osteomalacia.
5. It is mainly used in food, health products and other related products.
Production method
1. 7-dehydrocholesterol is dissolved in ethanol, and then treated with ultraviolet light to open the ring. The reaction mixture is concentrated, frozen and filtered. The filtrate is concentrated under reduced pressure nitrogen to dryness to give a crude liquid vitamin D3. Then it is refined to get vitamin D3.
2. Vitamin D3 naturally exists in the liver, egg yolk and milk. The production method in the industry starts from vegetable oil or yeast to extract 7-dehydrocholesterol that is not absorbed by the human body. Then it is dissolved in chloroform or cyclohexane. And then it converts to vitamin D3 by the ultraviolet radiation in the quartz glass flask.
3. Vitamin D3 naturally exists in the liver, egg yolk and milk. The production method in the industry starts from vegetable oil or yeast to extract 7-dehydrocholesterol that is not absorbed by the human body. Then it is dissolved in chloroform or cyclohexane. And then it converts to vitamin D3 by the ultraviolet radiation in the quartz glass flask.
Chemical Properties
White or colorless crystalline solid. Odorless;
Originator
Vitamin D, Country Life
Uses
Cholecalciferol and ergocalciferol are used for the control of rats
and mice.
Uses
selective phosphodiesterase-4 inhibitor (PDE-4 inhibitor) under investigation for treating respiratory diseases involving chronic inflammation such as asthma or COPD (smoker’s lung)
Uses
carnitine replenisher in peripheral arterial disease
Uses
The vitamin that mediates intestinal calcium absorbtion, bone calcium metabolism and probably, muscle activity. Occurs in and is isolated from fish liver oils. Vitamin D acts through a receptor that i
s a member of the ligand-dependent transcription factor superfamily. Modulates the proliferation and differentiation of both normal and cancer cells. Has antiproliferative and antimetastatic effects o
n breast, colon, and prostate cancer cells. Activated vitamin D receptors in intestine and bone maintain calcium absorbance and homeostasis.
Uses
Vitamin D3 analogue.
Indications
Vitamin D is the collective term for a group of compounds
formed by the action of ultraviolet irradiation on
sterols. Cholecalciferol (vitamin D
3) and calciferol (vitamin
D
2) are formed by irradiation of the provitamins 7-
dehydrocholesterol and ergosterol, respectively. The
conversion to vitamin D3 occurs in the skin. The liver is
the principal storage site for vitamin D, and it is here that
the vitamin is hydroxylated to form 25-hydroxyvitamin
D. Additional hydroxylation to form 1,25-dihydroxyvitamin
D occurs in the kidney in response to the need for
calcium and phosphate
Definition
A free vitamin D
3, isolated in crystalline state from
the 3,5-dinitrobenzoate, produced by irradiation,
and equivalent in activity to vitamin D3 of tunaliver oil.
Indications
Vitamin D
3, through its active metabolite, 1,25-
(OH)
2D
3, also plays an important role in maintaining
calcium homeostasis by enhancing intestinal calcium
absorption, PTH-induced mobilization of calcium from
bone, and calcium reabsorption in the kidney.
Manufacturing Process
5 g of 7-dehydrocholesteryl acetate (prepared by W.R. Ness, R. S. Kostic and
Mosetting, J. Am. Chem. Soc. 78, 436, 1956) were dissolved in 500 ml of nhexane. This solution was irradiated with ultraviolet ray by recyclicly passing it
through a quartz apparatus surrounding 450 w high pressure mercury vapor
lamps for 80 minutes. After irradiation and then the distillating off of nhexane the solution was added with 50 ml of ethanol and the ethanolic
solution was left to stand overnight at the temperature of -20°C. The formed
crystals were filtered off from ethanolic solution and filtrate was heated at the
temperature 78°C for 4 hours. After cooling of filtrate, the cooled filtrate was
added with 4 ml of ethanolic solution containing 0.7 g of potassium hydroxide
to effect a reaction at the temperature of 20°C and under nitrogen for 60
minutes. The reaction product was added with 0.7 ml glacial acetic acid and
then ethanol was distilled off under reduced pressure from the reaction
product. The obtained residue was extracted with 50 ml of n-hexane and
extract was washed with water and n-hexane was distilled off from extract to
obtain 2.5 g of yellow oily matter containing vitamin D3. The content of
vitamin D3 in yellow oily matter was 40.2% by weight.
Therapeutic Function
Vitamin, Antirachitic
Biosynthesis
The primary supply of vitamin D
3 in humans is not obtained
from the diet but rather is derived from the ultraviolet
photoconversion of 7-dehydrocholesterol to vitamin
D
3 in skin. Thus, vitamin D
3 synthesis varies with the seasons.
D
3 is a prohormone and requires further metabolic
conversion to exert biological activity in its target organs. The liver and the kidney are the major sites
of metabolic activation of this endogenous sterol hormone.
The initial transformation of D3 occurs in the liver
and is catalyzed by the enzyme 25-OH-D
3-hydroxylase
to form 25-(OH)D
3; this is the primary circulating form
of D
3. Circulating 25-(OH)D
3 is then converted by the
kidney to the most active form of D
3, 1,25-(OH)
2D
3, by
the 1-(OH)-D
3-hydroxylase enzyme. Blood concentrations
of 1,25-(OH)
2D
3 are approximately one fivehundredth
of those of 25-(OH)D
3. 1, 25-(OH)
2D
3 is converted
to the metabolite 24R,25-(OH)
2D
3, which is capable
of suppressing parathyroid secretion.
In addition to the endogenous metabolites, some exogenous
sterols possess biological activity similar to
that of D
3. Ergocalciferol (vitamin D
2) is derived from
the plant sterol ergosterol and may act as a substrate for
both the 25-hydroxylase and the 1-hydroxylase enzyme
systems of the liver and kidney to form 25-(OH)D
2 and
1,25-(OH)
2 D
2, respectively. Ergocalciferol (vitamin D
2)
is the form used in commercial vitamins and supplemented
dairy products. Dihydrotachysterol, another
sterol that is used as a therapeutic agent, also functions
as a substrate for the hydroxylase enzymes in the liver
and kidney.
General Description
Fine colorless crystals. Water insoluble.
Air & Water Reactions
Sensitive to moisture, air and light. . Water insoluble.
Reactivity Profile
Vitamin D3 may react vigorously with strong oxidizing agents. May react exothermically with reducing agents to release hydrogen gas.
Health Hazard
SYMPTOMS: Symptoms of exposure to Vitamin D3 may include weakness, fatigue, lassitude headache, nausea, vomiting, diarrhea, polyuria, polydipsia, nocturia, decrease urinary concentrating ability, proteinuria, tissue calcification, hypertension and osteoporosis.
Fire Hazard
Flash point data for Vitamin D3 are not available. Vitamin D3 is probably combustible.
Agricultural Uses
Rodenticide: Used in bait for vermin control. Vitamin D is a steroid hormone that has an important role in regulating body
levels of calcium and phosphorus, and in mineralization of
bone. Not approved for use in EU countries. Registered
for use in the U.S. and other countries.
Trade name
DELSTEROL®; DEPARAL®; D3-
VIGANTOL®; QUINTOX®; RAMPAGE®; RICKETON®;
TRIVITAN®; VIGORSAN®; VITINC DAN-DEE-3®
Biochem/physiol Actions
Vitamin D acts through a receptor that is a member of the ligand-dependent transcription factor superfamily. Modulates the proliferation and differentiation of both normal and cancer cells. Has antiproliferative and antimetastatic effects on breast, colon, and prostate cancer cells. Activated vitamin D receptors in intestine and bone maintain calcium absorbance and homeostasis.
Mechanism of action
1, 25-(OH)
2D
3 exerts its influence within target tissues
through high-affinity sterol-specific intracellular receptor
proteins.The D
3 receptor, similar to steroid receptor
systems, translocates the hormone from the cell cytoplasm
to the nucleus, where biological response is initiated
via transcription and translation.
Clinical Use
The principal disorder associated with inadequate
vitamin D intake is rickets. The low blood calcium and
phosphate levels that occur during vitamin D deficiency
stimulate parathyroid hormone secretion to restore calcium
levels. In children, this deficiency
leads to the formation of soft bones that become deformed
easily; in adults, osteomalacia results from the
removal of calcium from the bone.Vitamin D deficiency
may occur in patients with metabolic disorders, such as
hypoparathyroidism and renal osteodystrophy. The requirement
for vitamin D is slightly higher in members
of darker-pigmented races, since melanin interferes
with the irradiation that produces vitamin D
3 in the
skin. People with limited exposure to the sun may need
to supplement vitamin D intake.
Side effects
The hypercalcemia resulting from hypervitaminosis
D is responsible for toxic symptoms such as muscle
weakness, bone pain, anorexia, ectopic calcification, hypertension,
and cardiac arrhythmias. Toxicity in infants
can result in mental and physical retardation, renal failure,
and death.
Safety Profile
Poison by ingestion. An
experimental teratogen. When heated to
decomposition it emits acrid smoke and
irritating fumes.
Potential Exposure
Sterol rodenticide used in bait for vermin control. Vitamin D is a steroid hormone that has an important role in regulating body levels of calcium and phosphorus, and in mineralization of bone. Not approved for use in EU countries
Drug interactions
Potentially hazardous interactions with other drugs
Antiepileptics: the effects of vitamin D may
be reduced in patients taking barbiturates or
anticonvulsants.
Diuretics: increased risk of hypercalcaemia with
thiazides.
Sevelamer: absorption may be impaired by sevelamer.
Metabolic pathway
Cholecalciferol (vitamin D3) is the mammalian form of vitamin D. It is
normally produced in the skin by the action of UV light on its precursor, 7-
dehydrocholesterol. Essential amounts of the vitamin are obtained thus or
from dietary sources such as fish oils. The active form of the vitamin is
1,25-dihydroxy-cholecalciferol. Its formation occurs in two stages: 25-
hydroxylation in the liver, followed by 1-hydroxylation in the kidney (see
Engstrom and Koszewski, 1989 and references cited therein).
Metabolism
Within the liver, cholecalciferol is hydroxylated to
calcidiol (25-hydroxycholecalciferol) by the enzyme
25-hydroxylase. Within the kidney, calcidiol serves as
a substrate for 1-alpha-hydroxylase, yielding calcitriol
(1,25-dihydroxycholecalciferol), the biologically active
form of vitamin D3.
Cholecalciferol and its metabolites are excreted mainly in
the bile and faeces.
Shipping
UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required
Purification Methods
It is converted into its 3,5-dinitrobenzoyl ester and crystallised repeatedly from acetone. The ester is then saponified and the free vitamin is isolated. [Laughland & Phillips Anal Chem 28 817 1956, Beilstein 6 III 2811, 6 IV 4149.]
Degradation
It is unstable in light and air and in acidic media.
It is inactivated within a few days under normal exposure conditions. This
is due to oxidation and fragmentation of the triene functionality.
Toxicity evaluation
Another steroidal rodenticide is
cholecalciferol, which is in fact the naturally occurring
vitamin D3. This compound is an essential factor for
vertebrates but in large doses causes hypercalcemia,
resulting in calcification and degeneration of various
soft tissues, ultimately leading to death. In baits,
cholecalciferol may be combined with other, usually
anticoagulant, rodenticides. The main natural source of
cholecalciferol is fish liver oil, but it is manufactured from
ergosterol.
Incompatibilities
Sensitive to air, light, and moisture. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.
Waste Disposal
Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material’s impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.
