hlo dr my son is three and half years old.... he is very skinny n do not take Enough diet what should I do?

A. Aptivate 1 teaspoon half an hour before lunch and similarly 1 teaspoon half an hour before dinner you can give for a month that should be helpful but provide you take this medicine would advise you to get a nutritional deficiency test done once it could be due to some deficiency in the body as well