Bones may weaken after weight loss surgery
Patients lose bone density after weight loss surgery, and the more weight they lose, the greater the drop, new research shows. To investigate, they followed 23 men and women who had undergone Roux-en-Y gastric bypass surgery. This operation involves bypassing the duodenum, the portion of the small intestine that joins to the stomach—the chief site of calcium absorption by the body. Before the surgery, the patients had less-than-optimal blood levels of vitamin D, even though their intake of the nutrient was relatively high. After the surgery, they doubled their calcium intake and were consuming 2.6 times more vitamin D, but their blood levels of vitamin D remained low, and their blood levels of calcium actually fell. Signs of poor calcium absorption appeared within three months of the surgery. The density of their upper thigh bones had dropped by 9.2 per cent and their hip bone density fell by eight per cent but most patients didn’t show loss of bone density in the lower back or the forearm.