Ay, hindi normal yan, mama! Vitamin C chewables can be acidic talaga, kaya sometimes it irritates the throat or causes discomfort, but kung tumatagal siya or parang medyo serious, better check with your doctor para sure kung okay lang sa kanya yung brand or dosage na yan. A few of us had the same issue, so we switched to the non-chewable kind or pinagsama lang sa juice para less direct contact sa throat, pero definitely consult your pediatrician first to make sure walang underlying issue, okay?