Bone and Gastric Bypass Surgery: Effects of Dietary Calcium and Vitamin D
Article first published online: 6 SEP 2012
2004 North American Association for the Study of Obesity (NAASO)
Volume 12, Issue 1, pages 40–47, January 2004
How to Cite
Goode, L. R., Brolin, R. E., Chowdhury, H. A. and Shapses, S. A. (2004), Bone and Gastric Bypass Surgery: Effects of Dietary Calcium and Vitamin D. Obesity Research, 12: 40–47. doi: 10.1038/oby.2004.7
- Issue published online: 6 SEP 2012
- Article first published online: 6 SEP 2012
- Received for review March 17, 2003; Accepted in final form October 24, 2003
- parathyroid hormone;
- Roux-en-Y gastric bypass;
- vitamin D
Objective:To examine bone mass and metabolism in women who had previously undergone Roux-en-Y gastric bypass (RYGB) and determine the effect of supplementation with calcium (Ca) and vitamin D.
Research Methods and Procedures: Bone mineral density and bone mineral content (BMC) were examined in 44 RYGB women (≥3 years post-surgery; 31% weight loss; BMI, 34 kg/m2) and compared with age- and weight-matched control (CNT) women (n = 65). In a separate analysis, RYGB women who presented with low bone mass (n = 13) were supplemented to a total 1.2 g Ca/d and 8 μg vitamin D/d over 6 months and compared with an unsupplemented CNT group (n = 13). Bone mass and turnover and serum parathyroid hormone (PTH) and 25-hydroxyvitamin D were measured.
Results:Bone mass did not differ between premenopausal RYGB and CNT women (42 ± 5 years), whereas postmenopausal RYGB women (55 ± 7 years) had higher bone mineral density and BMC at the lumbar spine and lower BMC at the femoral neck. Before and after dietary supplementation, bone mass was similar, and serum PTH and markers of bone resorption were higher (p < 0.001) in RYGB compared with CNT women and did not change significantly after supplementation.
Discussion: Postmenopausal RYGB women show evidence of secondary hyperparathyroidism, elevated bone resorption, and patterns of bone loss (reduced femoral neck and higher lumbar spine) similar to other subjects with hyperparathyroidism. Although a modest increase in Ca or vitamin D does not suppress PTH or bone resorption, it is possible that greater dietary supplementation may be beneficial.