Chapter 24

True or false? PTH and \(1,25(\mathrm{OH})_{2} \mathrm{D}\) (vitamin \(\mathrm{D}\) ) are the principal hormones involved in the normal physiologic regulation of calcium homeostasis.

vTrue or false? Cod liver oil (ugh!) is a source of vitamin D.

True or false? PTHrP is produced by some cancers and often leads to cancerassociated hypercalcemia.

True or false? \(1,25(\mathrm{OH})_{2} \mathrm{D}\), due to 1 -hydroxylase activity in macrophages, may be produced to excess in granulomatous diseases and lymphoid disorders, leading to hypercalcemia.

True or false? Teriparatide is the only drug currently approved by the FDA for the treatment of osteoporosis that directly stimulates bone formation (i.e., it is not an antiresorptive drug).