Background:

Malabsorption of micronutrients including calcium and vitamin D may lead to pathological bone fractures in the late postoperative period of bariatric surgery.

Aims:

The aim of this study was to evaluate the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on bone mineral density (BMD) and calcium and vitamin D intake after 3 years of surgery.

Methods:

Cross-sectional study that included 66 patients in the late postoperative period of bariatric surgery to analyze their BMD. Anthropometric and demographic data were collected, and a 24-hour recall questionnaire was carried out to assess food consumption patterns. BMD was assessed by bone densitometry of the femur and spine, and the values were expressed as z-scores.

Results:

The mean age was 40.1 years, 86.4% were female. RYGB was performed in 60.3% and SG in 39.7%. There was no significant difference between the techniques when comparing anthropometry, body composition, and food consumption patterns. There was a positive correlation, after RYGB, between femoral z-score, calcium and vitamin D intake, and multivitamin supplementation. A total of 12.7% of the sample had compromised bones, and among these, 87.5% underwent RYGB, 100% had inadequate consumption of calcium and vitamin D, and 12.5% were in menopause.

Conclusions:

A small percentage of the sample showed bone loss after RYGB and SG. The type of surgery was not a significant factor in changing BMD. However, all those affected had a low intake of calcium and vitamin D.