Vitamin D3
Chemical Name: Cholecalciferol
Chemical Formula： C₂₇H₄₄O
Molecular Weight: 384.64
Properties： Vitamin D3 is colorless acicular crystals or white crystalline powder, odorless and tasteless. It is prone to deterioration when exposed to light or air. It is insoluble in water but soluble in organic solvents such as ethanol, chloroform, and ether.
CAS Number: 67 - 97 - 0
Chemical Formula： C₂₇H₄₄O
Molecular Weight: 384.64
Properties： Vitamin D3 is colorless acicular crystals or white crystalline powder, odorless and tasteless. It is prone to deterioration when exposed to light or air. It is insoluble in water but soluble in organic solvents such as ethanol, chloroform, and ether.
CAS Number: 67 - 97 - 0
- Main Sources
- Endogenous Synthesis: 7 - Dehydrocholesterol in human skin undergoes a photochemical reaction under the irradiation of ultraviolet B (UVB) in sunlight and is converted into vitamin D3. This is an important way for the human body to obtain vitamin D3. Generally, exposing the skin to sunlight for 15 - 30 minutes, 2 - 3 times a week, can meet part of the body's vitamin D3 needs. However, the specific synthesis amount is affected by various factors such as skin color, sunshine duration, season, and latitude.
- Food Sources: Foods rich in vitamin D3 are relatively scarce. They mainly include deep - sea fish (such as salmon, tuna, cod, etc.), animal livers (such as pig liver, beef liver, etc.), and egg yolks. In addition, some dairy products, soy products, and cereal products are fortified with vitamin D3 to increase their nutritional value.
- Main Functions
- Calcium Absorption and Bone Health**: The main function of vitamin D3 is to promote the absorption of calcium and phosphorus in the intestine, increase the levels of blood calcium and blood phosphorus, and help maintain the normal growth, development, and mineralization of bones. It can work in synergy with parathyroid hormone and other factors to regulate calcium and phosphorus metabolism, deposit calcium in bones, enhance bone strength and density, and prevent rickets in children and osteoporosis in adults.
- Immune Regulation: Vitamin D3 also plays an important role in the immune system. It can regulate the functions and activities of immune cells, enhance the body's immunity, and help the body resist infections and diseases. Research has found that a deficiency of vitamin D3 may be associated with an increased risk of various autoimmune diseases (such as rheumatoid arthritis, multiple sclerosis, etc.).
- Other Functions: More and more research shows that vitamin D3 may be related to various physiological processes such as cardiovascular health, muscle function, and mood regulation. For example, it may help reduce the risk of hypertension and cardiovascular diseases, improve muscle strength and function, and may also have a certain effect on preventing mental illnesses such as depression.
- Deficiency and Excess
- Deficiency Symptoms: In children, vitamin D3 deficiency can lead to rickets, manifested as skeletal developmental deformities such as pigeon chest, O - shaped legs, or X - shaped legs. There may also be symptoms such as excessive sweating and irritability. In adults, vitamin D3 deficiency causes osteomalacia, resulting in bone pain, muscle weakness, etc., increasing the risk of osteoporosis and fractures. In addition, long - term vitamin D3 deficiency may also affect immune system function, making people more susceptible to diseases.
- Excess Hazards: Although vitamin D3 is important for health, excessive intake can also harm the body. Long - term excessive intake of vitamin D3 may lead to hypercalcemia, causing symptoms such as nausea, vomiting, loss of appetite, polyuria, and polydipsia. In severe cases, it may lead to kidney stones, vascular calcification, etc., affecting heart and kidney functions.
- Supplementary Suggestions
- For most people, appropriate sunlight exposure and a balanced diet can generally meet the daily needs of vitamin D3. However, for some special groups such as the elderly, pregnant women, lactating women, vegetarians, indoor workers, and people with darker skin tones, additional vitamin D3 supplementation may be required.
- When supplementing vitamin D3, it is advisable to follow the advice of doctors or nutritionists and not blindly over - supplement. Generally, the recommended daily intake of vitamin D3 for adults is 5 - 10 micrograms. The elderly, pregnant women, and lactating women may need to appropriately increase the intake, but it should not exceed the tolerable upper intake level (generally 50 micrograms per day).
