Hello sir, your child is big enough to eat with the family. Cow's milk can be started. Give him all the foods that you eat. If not begun weaning, start with cerelac, daliya, khichdi, dal water, rice, mashed potatoes, banana, even roti also. Avoid nuts because they can get stuck in throat. Health supplements do not have much role if you are giving him proper diet. At this age, milk should only be 2-3 times a day.