If 6-month-old babies are normally breastfed and supplemented with complementary foods, they usually do not need to take calcium supplement alone. If you need to supplement calcium, you can take calcium gluconate oral solution, pediatric calcium carbonate D₃ granules, etc., but the effect of individual differences, there is no best said. 1. Calcium gluconate oral solution: used for the prevention or treatment of calcium deficiency, such as pregnancy, the elderly, lactation, children’s calcium supplementation, tetany, rickets, osteogenesis imperfecta. Adverse reactions can be seen constipation. Allergic to the product, hypercalcemia and other people are prohibited. 2.Pediatric Calcium Carbonate D₃ Granules: used for children’s calcium supplementation. Adverse reactions can be seen hiccups, constipation, hypercalcemia and so on. Hypercalcemia, hyperuricemia, allergy to this product is prohibited. The effect of calcium supplementation is affected by baby’s absorption, the degree of calcium deficiency and other factors, there are individual differences, there is no such thing as the best. Generally speaking, normal breastfeeding or formula-fed 6-month-old babies with normal complementary foods do not need to take calcium supplements, and if they need to take calcium supplements, they should follow the doctor’s instructions for medication.