GBP induces a significant BMD loss related with changes in body composition, although some metabolic mediators, such as adiponectin increase, may have an independent action on BMD which deserves further study.

Iron absorption is markedly reduced after RYGBP with no further modifications, at least until 18 mo after surgery.

One year after gastric bypass, bone mineral density was significantly affected, mainly at the femoral neck. Decreases in bone mineral density were more dramatic among patients who had greater baseline BMD and greater reduction in ghrelin concentrations.

Despite high daily energy intake and adequate macronutrient distribution, morbidly obese Chilean women seeking bariatric surgery present with deficient intake of some micronutrients and a high prevalence of micronutrient deficiencies.

Iron (heme and nonheme) absorption is markedly reduced after SG and RYGBP. The magnitude of the decrease in heme-iron absorption is greater than that of nonheme iron. The amounts suggested as iron supplements may need to be increased to effectively prevent iron-status impairment.