Vitamin D, 1, 25- Dihydroxy, Serum

1,25-dihydroxy vitamin D (1,25 (OH)2 Vit D), the active and potent form of vitamin D, is produced from 25-hydroxy vitamin D by the action of the kidney enzyme 1-α-hydroxylase. It regulates calcium and phosphate homeostasis and is essential for the development and maintenance of bone. Vitamin D is essential for the interaction between the kidney, parathyroid, bone and intestine. It is essential to enhance the efficiency of the small intestine to absorb dietary calcium and phosphate, it is essential for the development and maintenance of a mineralised skeleton, it is a potent modulator of parathyroid function and exerts tight control of its own homeostasis through simultaneous suppression of 1-α-hydroxylase by the kidney. Other target tissues of 1,25 (OH)2 Vit D not involved in calcium homeostasis include the skin, muscle, pancreas, reproductive organs and the haematopoietic, immune, and nervous systems. See Also Vitamin D, 25-Hydroxy, Serum

Traditionally, Vitamin D is used in the diagnosis of rickets. Vitamin D deficiency causes parathyroid hyperplasia and secondary hyperparathyroidism. Anaemia, decreased bone cellularity, extramedullary erythropoiesis, time-dependent reduction in spleen colony forming units and recurrent infections have been reported in vitamin D deficiency. More recently, epidemiological evidence links vitamin D deficiency with cancer, autoimmune diseases, hypertension and diabetes

2 ml Serum or EDTA Plasma Frozen

pg/mL <16 Yrs 24.0-86.0 Female ≥ 16 Yrs 18.0-78.0 Male ≥ 16 Yrs 18.0-64.0