What is the active form of vitamin d (calciferol)?
1,25-dihydroxyvitamin D
(1,25-(OH)2 D3, calcitriol)
List causes of Vitamin D toxicity.
Oversupplementation
Granulomatous disorders (e.g., sarcoidosis): due to increased 1α-hydroxylase activation in epithelioid macrophages → increased 1,25-dihydroxyvitamin D synthesis
List clinical features of vitamin D toxicity.
Hypercalcemia, hypercalciuria (see also laboratory evaluation of bone disease)
Loss of appetite
Stupor
Describe the serum calcium, serum phosphate, and parathormone (PTH) as well as additonal diagnostic tests of hypervitaminosis D.
Serum calcium: ↑
Serum phosphate: ↑
PTH: ↓
Additional tests:
↑ Vitamin D
Can be caused by sarcoidosis or oversupplementation
Hypercalciuria
Last changed2 years ago