BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Vitamin D functions by stimulating intestinal calcium and phosphorus absorption, by stimulating bone calcium mobilization, and by increasing renal reabsorption of calcium in the distal tubule.

Detailed explanation-2: -Parathormone and vitamin D enhance calcium and phosphorus absorption in the intestine; at the renal level parathormone helps absorb calcium but promotes phosphorus excretion, while vitamin D enhances both calcium and phosphorus renal absorption.

Detailed explanation-3: -Vitamin D is a secosteriod hormone essential for calcium absorption and bone mineralization which is positively associated with bone mineral density [BMD]. It is well-established that prolonged and severe vitamin D deficiency leads to rickets in children and osteomalacia in adults.

Detailed explanation-4: -It provides essential nutrients to maintain bone formation. Phosphorus works with calcium to increase bone-strengthening benefits. Vitamin D3 helps the body to absorb calcium and phosphorous. Thereby, increases calcium levels in the blood and helps to build and maintain strong bones.