What is active vitamin D and what is the active form of vitamin D?

Active vitamin D3

It is used for osteoporosis.

A substance that promotes bone formation and increases bone mass. Contraindicated in patients with hypercalcemia.

Active vitamin D3 is a white crystalline powder; Odorless, tasteless; It is easy to deteriorate when exposed to light, humidity and heat. in ethanol or methylene chloride.

Moderately soluble, soluble in ether, almost insoluble in water. The melting point (Appendix C of Part II of the 2010 edition of the Pharmacopoeia) is 137 142, and it decomposes at the same time when melting.

take active vitamin D3, weigh it accurately, and add absolute ethanol.

Dissolve and quantitatively dilute to prepare a solution containing approximately 1 ml, determined according to law (Appendix E of Part II of the 2010 edition of the Pharmacopoeia), and the specific rotation is + to +.

Active vitamin D3 refers to 1,25--dihydroxyvitamin D3, which is a form of vitamin D that is truly physiologically formed by two hydroxylations in the liver and kidney.

Isn't it a supplement with the necessary vitamins for the human body?

The main active form of vitamin D is 1,25-dihydroxyvitamin D3, which can play a role in the small intestinal mucosa, kidney and renal tubules, mainly to promote the absorption of calcium, but also to promote the absorption of phosphorus, which is conducive to the formation and calcification of new bone.

Vitamin D is a fat-soluble vitamin, commonly known as D2 and D3, called ergocalciferol and cholecalciferol, respectively. Normally, it is mainly a part of plant food, and more importantly, some animals. In addition, 7-dehydrocalciferol, which is converted from cholesterol below, is converted into vitamin D3 by ultraviolet light.

The main role of vitamin D

It regulates calcium and phosphorus metabolism, promotes intestinal calcium and phosphorus absorption and bone calcification, and maintains the balance of blood calcium and blood phosphorus. Active vitamin D acts on the nucleus of small intestinal mucosal cells and promotes calcineurin biosynthesis. Calcinin and calcium combine into a soluble complex, which accelerates calcium absorption.

Vitamin D promotes phosphorus absorption, possibly indirectly by promoting calcium absorption. Therefore, the total effect of active vitamin D on calcium and phosphorus metabolism is to increase blood calcium and blood phosphorus, so that the plasma calcium and plasma phosphorus levels reach a saturation degree. It is beneficial for calcium and phosphorus to be deposited on bone tissue in the form of bone salts to promote bone tissue calcification.

The active form of vitamin D is 1-25 dihydroxyvitamin D3, and 1-25 dihydroxyvitamin D3 is dihydroxyvitamin D3, also known as calcitriol, which is the active form of vitamin D.

Vitamin D is a fat-soluble vitamin, which is a cyclopentane polyhydrophenanthrene compound, a group of structurally related to sterols, the most important being vitamins D3 and D2. Vitamin D is an essential nutrient for the maintenance of life in higher animals, and is a general term for a family of molecules with the same structure of A, B, C, and D rings but different side chains.

Vitamin D is the main **

1. Dried shiitake mushrooms. Dried shiitake mushrooms are rich in many nutrients, especially vitamin D, which is 8 times higher than that of fresh shiitake mushrooms, because the drying process increases the vitamin D content.

2. Egg yolk. Egg yolks are a nutritional star, rich in vitamin D and B vitamins, with almost half the protein content of whole eggs, and cholesterol in them does not increase the risk of heart disease.

3. Tuna. Fatty tuna is rich in vitamin D and omega-3 fatty acids, rich in protein, and rich in selenium, which boosts the body's immunity.

4. Cod liver oil. Cod liver oil provides vitamin A, which helps protect immunity and heart and eye health.

Active vitamin D3 is a substance used for osteoporosis, promoting bone formation, and increasing bone mass. Contraindicated in patients with hypercalcemia.

The vitamin D3 in the active ashwagandha is a white crystalline powder; Odorless, tasteless; It is easy to deteriorate when exposed to light, humidity and heat. Soluble in ethanol or methylene chloride, soluble in ether, almost insoluble in water. The melting point (Appendix C of Part II of the 2010 edition of the Pharmacopoeia) is 137 142, and it decomposes at the same time when melting.

Take the active vitamin D3, weigh it accurately, add absolute ethanol to dissolve and quantitatively dilute it to prepare a solution containing about 1ml per 1ml, and determine it according to law (Appendix E of Part II of the 2010 edition of the Pharmacopoeia), and the specific rotation is + to +.

Active vitamin D is produced by ultraviolet irradiation of the corresponding provitamin D.

Provitamin D is a cyclopentane polyhydrophenanthrene compound. The 5,7 bits in the pro-B ring of vitamin D are double bonds, which can absorb light quanta with wavelengths of 270 300 nm, thereby initiating a series of complex photochemical reactions and finally forming vitamin D.

If the provitamin D is ergosterol, the light product is vitamin D2, and if the provitamin D is 7-dehydrocholesterol, the light product is vitamin D3.

Vitamin D2, also known as ergocalciferol, is mainly synthesized from plants, and has more yeast, ergot, etc.

Vitamin D3, also known as cholecalciferol, contains 7-dehydrocholesterol in the epidermis and ** tissues of most higher animals, which can be converted into vitamin D3 by photochemical reaction under sunlight or ultraviolet light.

is 25-(OH)2-d3

The active form of vitamin D is a hormone that is chemically similar to steroid hormones such as testosterone, estrogen, and cortisol, which regulates stress.

Vitamin D is a general term for vitamin D2 (VD2) and vitamin D3 (VD3), which have the biological activity of hormones after activation in the body (Note: It means that if you want to have hormonal activity, you must be activated).

VD3 undergoes a two-step hydroxylation in vivo before it becomes biologically active.

25-hydroxyvitamin D3 (25(OH)D3) is formed by hydroxylase in the liver.

It is then catalyzed by 1-hydroxylase in the kidney, which is again hydroxylated to the more active 1,25-dihydroxyvitamin D3.

1,25(OH)2d3 can also be synthesized by tissues and cells such as **, placenta, macrophages, etc.

The active forms of vitamin D3 mainly include 25-hydroxyvitamin D, 25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3, among which 1,25-dihydroxyvitamin D3 is the most biologically active.

25-hydroxyvitamin D3 is the main form of vitamin D in human blood circulation, and is often used as a detection index to evaluate the nutritional status of vitamin D in the spine body, but it only has a weak anti-rickets effect.

Note: The biological activity of 1,25-dihydroxyvitamin D3 is about 100-200 times that of 25-hydroxyvitamin D3.

After that, the activated vitamin D3 is further hydroxylated or oxidized and degraded, and excreted by liver and kidney metabolism.