Vitamin D is usually taken until the child is about two years old, after two years of age, if still accompanied by vitamin D deficiency, you can follow the doctor’s advice to continue to take, the time to take need to consult a doctor. Vitamin D is a fat-soluble vitamin, involved in the body’s calcium and phosphorus metabolism, to maintain the concentration of calcium ions in the blood and bone mineralization has an important role in life vitamin D from the sun, dietary intake, vitamin D supplementation to obtain. Vitamin D supplementation is recommended for newborns in about two weeks, and for preterm infants in about one week after birth, and is usually taken until the child is about two years old, but if some children still have vitamin D deficiency after the age of two, it is recommended that they continue to take the vitamin D supplementation under the guidance of a doctor, or stop taking the vitamin D supplementation if necessary, in accordance with the instructions of a doctor. Vitamin D until the child’s age, according to the child’s individual growth and development to decide, you can go to the hospital to let the professional doctor to judge.