Vitamin D deficiency in pregnant women may lead to weakness of limbs, leg and stomach cramps, dry skin, easy sweating, high blood pressure during pregnancy, diabetes, and rickets in newborns. Vitamin D is a common fat-soluble vitamin that promotes the absorption of calcium, which is very good for maintaining healthy bones. In the middle and late stages of pregnancy, the calcium absorbed by pregnant women from meals alone is no longer enough for the mother and baby to absorb, and in order to prevent congenital rickets and congenital skeletal insufficiency in newborns, active supplementation of calcium and vitamin D is needed. Vitamin D deficiency in pregnant women can also have a certain impact on pregnant women, easy to cause leg cramps, dry skin, etc., need to supplement vitamin D in a timely manner. It is important to actively supplement vitamin D during pregnancy under the guidance of a doctor, and in the event of pregnancy complications, a doctor is required to formulate an individualized diagnosis and treatment plan in order to avoid delays in the condition.