<s>[INST] Hi I m writing regarding my son aged 3 yrs 3 months. A year ago when on holiday he was hospitalized due to a stomach infection & his weight dropped to a 9 kgs. Since then he hasn t seemed to have passed 13kgs in weight & he is also undersized when compared to his birthweight & height. He has allergies to quite a few foods & has been advised to avoid cold foods like yogurt , cheese as it creates mucous in the chest & he falls sick easily. At this age are children to take multivitamins? I was also trying to find out the side effects of Mucolyte as he has recently been prescribed the same & today ( the 3rd day of his medication) he woke up with rashes on his cheeks. He has for the last 4 days been having an upset stomach & complains whenever he consumes milk based foods. I am quite concerned about him not having a normal growth. Would appreciate your advice on the above. [/INST] Hi, welcome to forum, I understand that your concern is child not gaining weight. A 3-year-old child should ideally be 14 kg and your child is 13 kg, that should be fine. May be growth velocity is what you are concerned about. If the child falls sick very often than surely weight gain will suffer. Hoping that the child is fully immunized. If not kindly do it. I would also advise to get Flu vaccine every year. You may please give multivitamin. And include fresh fruits and vegetables in his diet thanks </s>