Ca2+/Phosphate Metabolism

Question 1

What are the overarching causes of hypophosphatemia?

Answer 1

• internal redistribution
• decreased intestinal absorption
• increased urinary excretion

Question 2

What are causes of hypophosphatemia stemming from internal redistribution?

Answer 2

• increased insulin secretion (especially refeeding malnourished patients)
• acute respiratory alkalosis (stimulates glycolysis)
• hungry bone syndrome (after parathyroidectomy)

Question 3

What are the causes of hypophosphatemia stemming from decreased intestinal absorption?

Answer 3

• chronic poor intake
• aluminum or magnesium containing antacids (bind phosphate
• steatorrhea or chronic diarrhea

Question 4

What are the causes of hypophosphatemia stemming from increased urinary excretion?

Answer 4

• Primary and secondary hyperparathyroidism
• Vit D deficiency ( dec. GI absorption, inc urinary excretion)
• Primary renal phosphate wasting syndromes
• Fanconi syndrome