REEFCAL-DX 600/400 MG is a nutritional supplement that combines Calcium Carbonate (600 mg) and Vitamin D3 (Cholecalciferol 400 IU) to support healthy bones and teeth. It is specially formulated to help prevent and treat calcium and vitamin D deficiencies, particularly in individuals at risk of osteoporosis, postmenopausal women, pregnant or lactating women, and the elderly.