Changes

3. '''Decrease Calcium and Phosphorous excretion via the kidney''' - Calcitriol acts on the renal tubular epithelial cells to increase calcium and phosphorous reabsorption from the nephron. This action is WEAK compared to the action of PTH, which acts to reabsorb calcium but lose phosphorous from the nephron.

3. '''Decrease Calcium and Phosphorous excretion via the kidney''' - Calcitriol acts on the renal tubular epithelial cells to increase calcium and phosphorous reabsorption from the nephron. This action is WEAK compared to the action of PTH, which acts to reabsorb calcium but lose phosphorous from the nephron.

4. '''Normal bone functioning ([[Bones and Cartilage - Anatomy & Physiology|osteoclast and osteoblast functions]])''' - Calcitriol is needed for normal bone absorption and deposition. Without Vitamin D3, bone is not resorbed in response to PTH.

4. '''Normal bone functioning ([[Bones - Anatomy & Physiology#Composition of Bone|osteoclast and osteoblast functions]])''' - Calcitriol is needed for normal bone absorption and deposition. Without Vitamin D3, bone is not resorbed in response to PTH.

===Calcitonin===

===Calcitonin===