What is Vitamin D2?
Vitamin D2, also known as ergocalciferol, is one of the forms of vitamin D. It is a fat-soluble vitamin essential for human health. It is mainly found in plant foods and is ingested by the human body through food fortification or supplements. It is necessary for maintaining bone health and preventing the development of diseases such as osteoporosis.

What is Vitamin D3?
Vitamin D3, also known as cholecalciferol, is one of the forms of vitamin D. It is a fat-soluble vitamin essential for human health. It is mainly found in animal foods and is converted from 7-dehydrocholesterol when exposed to ultraviolet light through the skin. It is necessary for maintaining bone health and preventing the development of diseases such as osteoporosis.

Source
Vitamin D2:

Mushrooms: Some mushroom species can synthesize vitamin D2, especially after exposure to sunlight. This sun-exposed mushroom contains higher levels of vitamin D2 and is therefore considered one of the leading sources of vitamin D2 in plant foods.

Yeast: Yeast is also a plant food that contains vitamin D2. Some foods contain yeast, such as yeast extract, yeast additives, etc., which can provide a certain amount of vitamin D2.

Food fortification: Some foods, such as cereals, juices, soy milk, etc., may add vitamin D2 (or vitamin D3) during the production process to increase their nutritional value. These foods become another source of vitamin D2.

Vitamin D2 supplements: Vitamin D2 supplements can also provide vitamin D2. These supplements are often derived from plant-based sources and are suitable for vegetarians or those with allergies to animal-based foods.

Vitamin D3:

Fatty fish: Fatty fish is one of the primary sources of vitamin D3. Including cod, salmon, mackerel, seabass, and other fatty fish, their fatty tissue is rich in vitamin D3.

Cod liver oil: Cod liver oil is an oil extracted from fish livers and contains high concentrations of vitamin D3. In the past, cod liver oil was a common vitamin D3 supplement.

Egg yolk: Egg yolk also contains small amounts of vitamin D3. Eggs are a common ingredient in the daily diet, and the yolks contain a small amount of vitamin D3.

Liver: Animal liver is a nutrient-rich food that contains a certain amount of vitamin D3. Cod liver, in particular, contains higher levels of vitamin D3.

Sunlight: Skin can synthesize vitamin D3 independently when exposed to ultraviolet rays. When ultraviolet B (UVB) irradiates the skin, 7-dehydrocholesterol in the skin is converted into pre-vitamin D3 and then into vitamin D3. Therefore, sunlight is one of the primary sources of vitamin D3, which is naturally synthesized by the human body.

Food fortification: Vitamin D3 (or vitamin D2) may be added to some food products during the production process to increase their nutritional value, such as milk, orange juice, cereals, etc.

Functions
Vitamin D2:

Promote calcium and phosphorus absorption: Vitamin D2 promotes calcium and phosphorus absorption by regulating the expression of calcium and phosphorus transporters in intestinal epithelial cells. This helps maintain normal calcium and phosphorus levels in the blood, which is essential for bone health.

Bone Health: Vitamin D2 promotes calcium absorption and utilization, helping to maintain bone health and strength. Adequate vitamin D2 intake helps prevent bone diseases such as osteoporosis and osteomalacia.

Immune system support: Vitamin D2 plays a regulatory role in the immune system and can affect the function of immune cells and the regulation of inflammatory responses. Appropriate intake of vitamin D2 helps enhance the immune system's function and prevent infections and inflammatory diseases.

Cardiovascular health: Some research suggests that vitamin D2 may benefit cardiovascular health. Adequate vitamin D2 intake is associated with a reduced risk of cardiovascular disease and can help maintain the elasticity and health of blood vessels.

Nervous system function: Vitamin D2 is also essential for the normal function of the nervous system. It synthesizes neurotransmitters pro, tests neurons, and may have a specific protective effect in preventing neurodegenerative diseases.

Anti-inflammatory effect: Vitamin D2 has a specific anti-inflammatory effect, which can regulate the inflammatory response and reduce tissue damage caused by inflammation. Appropriate intake of vitamin D2 helps prevent and alleviate the occurrence of inflammatory diseases.

Vitamin D3:

Promote calcium and phosphorus absorption: Vitamin D3 promotes calcium and phosphorus absorption by regulating the expression of calcium and phosphorus transporters in intestinal epithelial cells. This helps maintain normal calcium and phosphorus levels in the blood, which is essential for bone health.

Bone health: Vitamin D3 promotes calcium absorption and utilization, helping maintain bone health and strength. Adequate vitamin D3 intake helps prevent bone diseases such as osteoporosis and osteomalacia.

Immune system support: Vitamin D3 plays a regulatory role in the immune system and can affect the function of immune cells and the regulation of inflammatory responses. Appropriate intake of vitamin D3 helps enhance the immune system's function and prevent infections and inflammatory diseases.

Cardiovascular health: Some research suggests that vitamin D3 may benefit cardiovascular health. Adequate vitamin D3 intake is associated with a reduced risk of cardiovascular disease and can help maintain the elasticity and health of blood vessels.

Nervous system function: Vitamin D3 is also essential for the normal function of the nervous system. It synthesizes neurotransmitters pro, tests neurons, and may have a specific protective effect in preventing neurodegenerative diseases.

Anti-inflammatory effect: Vitamin D3 has a specific anti-inflammatory effect, which can regulate the inflammatory response and reduce tissue damage caused by inflammation. Appropriate intake of vitamin D3 helps prevent and alleviate the occurrence of inflammatory diseases.

Maintain cardiovascular health: Vitamin D3 may help maintain cardiovascular health. Some studies have shown a link between vitamin D3 and the risk of cardiovascular disease, particularly hypertension, arteriosclerosis, and heart disease.

Target Audience
Vitamin D2:

Vegetarians and Vegans: Vitamin D2 mainly comes from plant foods, so vegetarians and vegans are more likely to suffer from insufficient vitamin D2 intake. They may need additional vitamin D2 supplements to meet their body's needs.

People who eat no or less animal-based foods: Those who eat no or less animal-based foods, such as strict vegetarians, partial vegetarians, or people who do not eat meat for specific cultural or religious reasons, may be at risk for vitamin D2 Risks of not getting enough. For these people, vitamin D2 supplements may be essential to keeping vitamin D levels regular.

Pregnant and nursing women: Pregnant and nursing women have increased vitamin D needs because adequate vitamin D intake is essential for healthy fetal and infant development. Especially for pregnant and breastfeeding women on a vegetarian or vegan diet, vitamin D2 supplements may be an option.

Elderly: As we age, the skin's synthesis ability weakens, so vitamin D synthesis in older people may be affected. In addition, older people may also face an unbalanced diet or insufficient exposure to sunlight, resulting in inadequate vitamin D2 intake. Therefore, vitamin D2 supplements are crucial for maintaining vitamin D levels in older people.

People with particular diseases or health problems: Some unique diseases or health problems, such as kidney disease, intestinal absorption disorder, osteoporosis, etc., may affect the absorption and utilization of vitamin D. For these people, vitamin D2 supplementation may be a therapeutic or preventive means of maintaining normal vitamin D levels.

Vitamin D3:

People who lack sufficient sun exposure: People who live in areas with less sunlight or who work indoors for long periods and lack adequate sun exposure may be at risk for vitamin D3 deficiency. Vitamin D3 supplements are essential for these people to maintain vitamin D levels.

Older adults: As age increases, the skin's synthesis ability weakens, and the kidneys' utilization efficiency of vitamin D may also decrease. Older adults are often at risk for vitamin D3 deficiency, especially if they eat an inadequate or restricted diet. Therefore, older adults may need additional vitamin D3 supplements to maintain normal vitamin D levels.

Pregnant and nursing women: Pregnant and nursing women have increased vitamin D needs because adequate vitamin D intake is essential for healthy fetal and infant development. Pregnant and nursing women, especially those with dietary or lifestyle restrictions, may need additional vitamin D3 supplements to meet their body's needs.

People with Osteoporosis: Osteoporosis is a disease in which bone density decreases due to the loss of calcium from the bones. Vitamin D3 is essential for maintaining bone health, so for patients with osteoporosis, appropriate intake of vitamin D3 is one of the vital measures to treat and prevent osteoporosis.

People with autoimmune diseases: Some autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, etc., may be related to vitamin D deficiency. Adequate vitamin D3 intake may help reduce disease symptoms and improve a patient's quality of life.

Vitamin D2 VS Vitamin D3