My daughter is 15 months old now. She has very low immunity she usually suffered with cold cough and stomach related infections most of the time. From last 4 months she is continuously ill any other next day . I am very helpless . I don't know what to do ? When she is fine she eats but the next moment when she is ill.. she stop eating and due to which she is not gaining weight properly and nutrition. Pls suggest if any supplements available for boosting immunity .