Vitamin AD drops and calcium supplements are necessary for children before the age of three to promote growth and development, calcium supplements commonly used are calcium lactate, calcium citrate, calcium carbonate D3 granules, calcium gluconate oral solution, etc. Organic calcium is more effective and has little effect when taken early or late. Note that before the age of one week only need to supplement vitamin AD drops or vitamin D preparations can be, it is generally recommended to choose vitamin AD, since you can supplement the vitamin D, you can also supplement vitamin A, vitamin A is also needed by the body, there are many babies lacking in China, long-term use of this dose will not be excessive, after the age of half can increase a small amount of calcium supplementation. When using also note that the dose of vitamin AD drops taken before and after one week of age is different.