Calex-D3 Tablet 30's belongs to the class of 'nutritional supplements', primarily used to treat low blood calcium levels. Calex-D3 Tablet 30's effectively treats various conditions caused by low calcium levels in the body like Vitamin D deficiency, osteoporosis (weak and brittle bones), hypoparathyroidism (parathyroid glands make low levels of calcium in the body), latent tetany (a muscle disease with low blood calcium levels), and rickets or osteomalacia (softening or deforming of bones due to lack of calcium).