The symptoms of calcium deficiency in babies at the age of 2 are as follows: 1. There will be difficulties in falling asleep, there will be sleep disturbances, and after falling asleep, they can suddenly wake up and cry, and after sleeping, there will be night sweats, which will appear as heavy sweating, like water washing. 3. Babies will occasionally show leg pain due to calcium deficiency, which is called growing pains. If a 2 year old baby has some of these manifestations, he or she needs to go to the hospital for a vitamin D and trace element calcium examination and be given further vitamin D and calcium supplements. Vitamin D is a medicine that facilitates calcium absorption, while supplementation can make calcium more quickly absorbed and utilized by the body.