Final answer:
D) cholecalciferol. Vitamin D, also known as cholecalciferol, raises the blood calcium level and regulates calcium absorption. It is synthesized in the skin through exposure to sunlight and metabolized in the liver and kidneys to its active form called calcitriol. Vitamin D deficiency can lead to bone disorders like rickets and osteomalacia.
Step-by-step explanation:
Vitamin D, also known as cholecalciferol, raises the blood calcium level. It is synthesized in the skin through the conversion of 7-dehydrocholesterol to cholecalciferol in the presence of sunlight. In the liver, cholecalciferol is further metabolized to calcidiol, and then in the kidneys, it is converted to the active form of vitamin D called calcitriol. Calcitriol regulates blood calcium levels by increasing the absorption of calcium and phosphorus from the intestine.
Vitamin D deficiency can lead to conditions like rickets in children and osteomalacia in adults, which are characterized by bone deformities and weakness. It is essential for the normal absorption of calcium and phosphorus, which are necessary for bone health.