Patients with primary hyperparathyroidism are at risk of osteoporosis - or thinning of the bones.  This puts patients at high risk of fractures after small falls or even spontaneous fractures e.g., of the spine.

Unfortunately who will develop osteoporosis is very difficult to predict.  The risk of osteoporosis is not related in any way to the levels of calcium or even parathyroid hormone in the blood.  Patients with only very slight elevations of calcium in the blood may well develop osteoporosis.

Studies show that 50% of patients with parathyroid disease will develop osteoporosis if left alone for 10 years.  This is really important as clearly it is much better to have surgery and fix the problem rather than watch bones deteriorate.

Treatment with drugs does not affect this.  So drugs such as bisphosphonates (alendronic acid is an example) will not necessarily prevent the bone loss.

This is another reason why early surgery is advisable for many patients particularly those with other risk factors for the development of osteoporosis.