Hello. Thank you asking at HCM. I would like to make following suggestions to you for your son: 1. Diet is a very important factor to improve immunity. Below are the tips that will be helpful: a. Make sure he is getting equal proportions of grains, nuts-legumes-beans, green leafy vegetables & fruits. In addition he should have a small proportion of milk & dairy products. b. Prefer whole grains over processed grains, please try to include sprouted legume/beans, please try to include all varieties of green leafy vegetables and fruits in diet. c. Personally I would suggest you to discourage excessive consumption of packed foods, junk foods, fried foods, cold beverages, etc. Try to replace these foods with above mentioned healthy foods . 2. If he is getting frequent fever/cough/colds, I would prescribe him vitamin C for at least 2-3 months. Also, I would suggest you to check his vitamin D levels as well as hemoglobin. If they are low, they should be treated. Hope this will be helpful to you. Wish your son the best of the health and I appreciate your awareness about improving his immunity. Should you have any further query, please feel free to ask at HCM. Thank you & Regards.