excess vit D causing OP

Started by ucbdancn00
This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

ucbdancn00

Senior Member
7+ Year Member
15+ Year Member
20+ Year Member
Advertisement - Members don't see this ad
pox....for you and anyone else

inc vit D (excess intake)--> increased Ca abs (intestinal/kidney absorption)
--> Decreased PTH (2ndary Hypoparathyrodism)--> increased phosphate;

couple of possibilities...

1) Over time increased phosphate may infact stimulate an increase in PTH--> there by allow dumping of the phosphate; PTH can stimulate osteoclast activities and cause OP

2) The vit D + PTH combo is required for Vit D to induce bone reportion (via osteblast signal to osteoclasts). Even though PTH may decrease, it doesn't go to zero.....so the Vit D + PTH can stimulate resorption

3) Increased phosphate may actually bind Ca2+ and prevent bone deposition and thereby lead to decreased bone mass over time. This may be the mechanism for "soft drinked" induced osteoporosis. With soft drinks, the increased phosphate in the digestive tract may make it more difficult for Ca2+ to be absorbed.

hope this helps

ucb