1, vitamin D is a fat-soluble vitamin, which plays a vital role in human body. Vitamin D has the functions of regulating calcium and phosphorus metabolism, promoting bone development and regulating immunity. If it is lacking for a long time, it will have many negative effects on the body.

2. The human body can synthesize a part of vitamin D by itself, but the amount of vitamin D synthesized by itself cannot meet the daily needs of the body. Unlike other vitamins, vitamin D is difficult to be supplemented by food, because there are not many foods rich in vitamin D.

3, vitamin D is a vitamin that the body is relatively easy to lack. Most people have vitamin D deficiency. If the body lacks vitamin D, there will be many manifestations in the body, reminding you that it is time to supplement vitamin D.