Vitamin D is a large family of vitamins that are important for maintaining the body’s calcium balance and are produced naturally in the human body. Vitamin D is known for its ability to prevent and treat rickets in children, but little else is known about its role. Today, medical research has found that vitamin D has a wide range of health effects. First, it plays an important role in preventing or reducing breast, lung and colon cancers. As early as 1937, the American scholar Peller (Peller) and others found that increased exposure to sunlight reduced the risk of cancer. Based on the scientific basis that vitamin D can be produced in the skin by sunlight exposure, scientists have conducted numerous epidemiological studies on vitamin D and tumors, which proved that Vitamin D deficiency is significantly associated with the development of many tumors, and the main active form of vitamin D in the body is 1,25(OH)2VitD3. 1,25(OH)2VitD3 has been found to have anti-tumor effects by inhibiting the growth and proliferation of tumor cells and reducing the invasion of tumor cells into surrounding tissues and distant metastasis. Secondly, vitamin D can prevent and control autoimmune diseases and infectious diseases, and also has a significant effect on cardiovascular protection in hypertensive patients. This effect may be related to its partial down-regulation of hormonal activities that can produce elevated blood pressure, such as: renin angiotensin system, parathyroid hormone secretion, glucagon, etc. Thirdly, vitamin D regulates the development and function of the placenta. Pregnant women who maintain good levels of vitamin D can prevent pregnancy complications such as miscarriage, pre-eclampsia and preterm delivery. Studies have also found that getting enough vitamin D in utero and in infants can reduce the incidence of type 1 diabetes, asthma and schizophrenia. Therefore, we can no longer underestimate the role of vitamin D like the eating public, and it is necessary to test your vitamin D levels regularly to know if you have vitamin D deficiency. Currently, vitamin D deficiency is widespread, especially in women, children, and the elderly. Diagnostic criteria for vitamin D deficiency Vitamin D deficiency: serum 25OHD <20ug/l Severe deficiency: serum 25OHD <10ug/l Vitamin D insufficiency: serum 25OHD 20ug/l-30ug/l Vitamin D sufficiency: serum 25OHD >30ug/l How to take vitamin D supplements ? 1, when taking vitamin D, should avoid drinking porridge soup. Because congee soup contains fat oxidase, which can dissolve and destroy fat-soluble vitamins and make vitamin AD and vitamin D loss. 2.Vitamin D mainly comes from animal food. Vitamin D mainly exists in sea fish, animal liver, egg yolk and lean meat. In addition, like skim milk, cod liver oil, cheese, nuts and seafood, added vitamin D fortified food, also rich in vitamin D. 3, the source of vitamin D is slightly different from other nutrients, in addition to food sources, but also from their own synthetic manufacturing, but this requires more sun exposure, to receive more ultraviolet radiation, but remember that the sun is not noon to sun, to be in the morning before 10:00 pm after 3:00 pm can The sun can only be used after 3:00 p.m., because there is too much harmful light at noon. 4, the general population is recommended to take vitamin D2 or vitamin D3, not active vitamin D or similar substances. It is worth noting that vitamin D should not be supplemented in excess, if you take vitamin D in excess, it will cause the body to accumulate too much vitamin D and symptoms of toxicity, such as loss of appetite, nausea and wasting.