There are a lot of reasons that HCV and TX can affect bone loss. I'm thinking the connection to SVR is that after getting rid of the virus and its assault on the liver, the liver is then able to repair enough to process the vitamin D so it can assist the absorption of calcium. Vit. D goes through 2 alterations before it can be used. The first takes place in the liver and the second in the kidney. The form they test for in Vit. D assays is the form that's been altered by the liver. Better liver function, better vit. D use. The TX connection is that it IFN could alter the parathyroid, invovled in bone breakdown. Riba has been found to affect absorption, protease inhibitors, too. Then there's the estrogen thing. Women have reduced estrogen on TX; so bone loss. All so complicated.