Lecture 26- Vit D, PTH and Ca regulation Flashcards
what factors impact how well someone can synthesize Vit D from sunlight?
- age
- strength of exposure (latitude)
- length of exposure
- race
What things influence conversion of 25-hydroxyvit D –> 1,25-hydroxyvitamin D?
- things associated with low 25-hydroxyvitamin D: high PTH, low phosphate
With hyperparathyroidism, explain the serum Ca, serum PO4-, vit D (25 and 1,25) and serum PTH.
serum Ca: high serum PO4-: low Vit D (25): normal Vit D (1,25): high PTH: high
With Vit D toxicity, explain the serum Ca, serum PO4-, vit D (25 and 1,25) and serum PTH.
serum Ca: high serum PO4-: high Vit D (25): high Vit D (1,25): normal-high PTH: low
With hypoparathyroidism, explain the serum Ca, serum PO4-, vit D (25 and 1,25) and serum PTH.
serum Ca: low serum PO4-: high Vit D (25): normal Vit D (1,25): low PTH: low
With Vit D deficiency, explain the serum Ca, serum PO4-, vit D (25 and 1,25) and serum PTH.
serum Ca: low serum PO4-: low Vit D (25): low Vit D (1,25): normal PTH: high
Signs of Hypercalcemia
Nepholithiasis Renal insufficiency Nephrocalcinosis Hypercalciuria Hematouria (passing stones)
If from excess PTH:
Decreased bone density
Fracture
Signs of hypocalcemia
Mild:
Circumoral numbness
Parethiasis
Cramps (muscle)
Severe: QT prolongation Chovestek's sign (carpopedal spasm) Laryngospasm Tetany Seizures (focal or general)
Signs of Vit D deficiency
Hypocalcemia Hyperphosphatemia Secondary hyperparathyroidism Inadequate bone mineralization Myopathy
Inadequate bone mineralization outcomes:
Osteomalacia
Osteoporosis
Rickets
Signs of Vit D excess
Hypercalcemia
Hyperphosphatemia
Hypercalciuria
PTH secretion inhibition
Signs of hyperparathyroidism
Hypercalcemia
Osteoporosis
Hypophosphatemia
Nephrolithiasis
Signs of hypoparathyroidism
Hypocalcemia
Hyperphosphatemia
