What is the role of renally activated calcitriol in calcium homeostasis?

  • Facilitates absorption of calcium from the small intestine 

  • Generated through the activity of parathyroid hormone (PTH) within the kidney

  • In combination with PTH it enhances fluxes of calcium out of the bone

  • Overall, acts to increase blood concentrations of calcium

Vitamin D also stimulates the absorption of phosphate and magnesium. Calcitriol that is activated in non-renal tissues and cells provides the explanation for the diverse range of vitamin D’s biological actions, including induction of cell differentiation, inhibition of cell growth, immunomodulation and control of other (autocrine/paracrine) systems. Modulation of immune cell activity reduces the risk of development of autoimmune diseases (such as rheumatoid arthritis, psoriasis, inflammatory bowel disease), enhances the ability to fight infectious disease and can prevent the unhealthy cell proliferative characteristic of some cancers.

Vitamin D2 or vitamin D3
Based on the current medical consensus as well as problems related to the measurement of vitamin D2, oral vitamin D3 is recommended as the vitamin D preparation of choice for the treatment of vitamin D deficiency.

Job code: FUL-519  
Date of preparation: June 2019