The best time for iron supplementation for infants and children should be two hours after meals. If iron is supplemented in an empty stomach, iron supplementation drugs usually stimulate the pediatric gastrointestinal tract, and children are prone to nausea, vomiting or diarrhea, which can easily affect the absorption of the drug. To avoid the effect of food on the drug, it is easy to affect the optimal bioavailability of the drug. If iron is taken orally immediately after eating, it is easy to affect the absorption of the drug and will affect the effect of the drug. Therefore, it should be taken orally two hours after the meal when the food is properly digested and not in an empty stomach, which will not stimulate the gastrointestinal tract of the child, but also facilitate the absorption of the drug and the best effect of the drug. Iron supplementation should be supplemented with vitamin C. Vitamin C facilitates the absorption of the drug and the absorption of iron.