Blood vitamin D

Vitamin D (VD) is a fat-soluble vitamin, which can be further divided into vitamin D2 and vitamin D3. Vitamin D2 is mostly found in plant-based foods and is synthesized from ergosterol in plants through sun exposure. Vitamin D3 can be synthesized in human skin and adipose tissue from 7-dehydrocholesterol through sun exposure. Vitamin D regulates calcium and phosphorus metabolism in the human body and plays a very important role in bone development and growth. Blood vitamin D, which measures the level of vitamin D in the blood, is an important indicator for evaluating whether the human body is deficient in vitamin D.