A four year old can take vitamin AD drops in case of vitamin AD deficiency in the body. Vitamin AD drops are vitamin-based medicines that are mainly used for the prevention and treatment of vitamin A as well as D deficiencies, such as rickets, night blindness, and pediatric tetany. Because vitamins A and D are essential for human growth and development, especially for the development of the fetus or infant, has an important role. For a four-year-old child with vitamin A and vitamin D deficiencies, vitamin AD drops medication can be given to improve the child’s symptoms. If medication is needed, it needs to be regulated under the guidance of a doctor and should not be taken on its own.