Vitamin D, one of our common fat-soluble vitamins, is an important substance that helps babies absorb calcium and plays an important role in the development of human bones and teeth. Vitamin D deficiency can lead to rickets in children and chondromalacia in adults. At present, the more well-known brands on the market are Icocin, Di Qiao, Hansen’s, Childhood CHILDLIFE, BabyDdrops, Prilosec, Nature’s Best, BY-HEALTH, Allergan, Amway, Cardinal K, Health and Beauty, Kirkland, Health and Beauty, MioHealth, Heris, Pepsi, Comfrey, Health and Beauty, etc. Vitamin D supplements are available in single-formula formulations: vitamin D drops. There are also compounded preparations: vitamin AD drops, vitamin AD softgels, calcium vitamin D vitamin K softgels, calcium vitamin D granules, calcium vitamin D softgels and other products. Infants need to consider the dosage form, the convenience of taking the medication, and the trustworthiness of the quality of the medication. From 2 weeks after birth until within 2 years of age, 400 IU of vitamin D supplementation per day is a must for infants and toddlers. It is important to note that babies must take the recommended dose and not overdose. Children should consult their physician or pharmacist for the dose to be taken. Children must be supervised by an adult when taking vitamin D. If a child overdoses or has a serious adverse reaction, he or she should seek immediate medical attention.