my son is 2years and 7months old he is very thin I tried many thing but not thing will happen I visited to doctor also he gave a vitamin but it's did not working please help me what should I do for my baby to became fat

A. U Then get it checked with your doctor for haemoglobin levels because a lot of times at this age when the haemoglobin level is not appropriate according to the age of the child a lot of times kids can face this issue as