Vitamin D: is to help your body maintain optimal blood levels of calcium and phosphorus, which you can get through exposure to the sun’s ultraviolet rays, or through supplements and the foods, you eat. When people receive enough vitamin D that can also protect them from a respiratory infection.
Vitamin D is sometimes called the “sunshine vitamin” because it’s produced in your skin in response to sunlight.
Vitamin D has several important functions. Perhaps the most vital are regulating the absorption of calcium and phosphorus and facilitating normal immune system function. Getting a sufficient amount of vitamin D is important for the normal growth and development of bones and teeth, as well as improved resistance against certain diseases.