Physiology PTH does what directly? A Controls the rate of 25-hydroxycholicalciferol formation B Controls the rate of calcium transpo in the mucosa of the small intestine C Controls the rate of formation of calcium-binding protein D Controls the rate of formation of 1,25-dihydroxycholicalciferol 💡 Explanation PTH does what directly? ✓ Correct Answer: D. Controls the rate of formation of 1,25-dihydroxycholicalciferol