Vitamin D helps maintain healthy bones and teeth. Participates in the absorption of calcium and phosphorus. Its deficiency can lead to rickets, the abnormal formation of bones and teeth. However, the amount of vitamin D in breast milk may not be sufficient. In addition, in autumn and winter, due to less sunlight, the synthesis of vitamin D in the skin is limited. For these reasons, it is recommended to supplement vitamin D deficiency in the daily diet of infants and children.