This improvemnt may take 2-3 years. It is imporatant to rule out osteomalcia or hyperparathryoidism which can occur. In the younger patients often all that is needed is a 1200mg calcium diet and adequate vitamin D and appropriate weight bearing exercise. Drugs like fosamax have really not been tested in celiac patients at all. It has not been used to any great extent in premenopausal women either.
Identical twins are genetically identical.
They share all the same genes. This tells us that the disease does have a strong base in genes, but something else is needed, some environmental factor to trigger the disease in a genetically susceptible host. On testing the gentically identical twin. The twin studies serve to illustrate the difference between a disease that is strictly genetic in it nature and one that has a genetic susceptibility. The questions you ask address what is really unknown in celiac disease research.