Shelcal-500 Tablet belongs to the class of 'Nutritional supplements', primarily used to treat low blood calcium levels. It effectively treats various conditions caused by low calcium levels in the body, such as Vitamin D deficiency, osteoporosis (weak and brittle bones), hypoparathyroidism (a condition in which the parathyroid glands produce 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 a lack of calcium).