Unformatted text preview: calcium absorption by the intestines. PTH does not inhibit intestinal absorption of calcium. In fact, PTH has an indirect role in increasing intestinal absorption of Ca 2+ by increasing the conversion of calcidiol to calcitriol In the absence of vitamin D, intestinal absorption of calcium will be reduced because calcitriol cannot be produced, so plasma calcium levels will be lower than normal. This would trigger the release of PTH to increase plasma calcium through other means, primarily via bone resorption. Sulfur is less electronegative than O, sulfur has a lower electron affinity than O, and sulfur is a larger atom than O. Sulfur—just like other elements in the third and lower rows in the periodic table—can exceed its valence octet because of the availability of a valence d orbital; O cannot because there is no 2 d orbital....
View
Full Document
- Spring '08
- Merill
- calcitriol, serum calcium
-
Click to edit the document details