Managing micronutrient deficiencies in the bariatric surgical patient

Bariatric surgery is associated with development of several micronutrient deficiencies that are predictable based on the surgically altered anatomy and the imposed dietary changes. The three restrictive-malabsorptive procedures-Roux-en-Y gastric bypass, biliopancreatic diversion, and biliopancreatic diversion with duodenal switch, pose a greater risk for micronutrient malabsorption and deficiency than the purely restrictive laparoscopic adjustable gastric banding. The newer laparoscopic gastric sleeve (LGS) procedure poses a unique risk due to partial resection of the stomach. Metabolic and clinical deficiencies of two minerals (iron and calcium) and four vitamins (thiamine, folate vitamin B₁₂, and vitamin D) have been well described in the literature. Deficiency of vitamin A and copper are reported less often. This chapter reviews the pathophysiology, clinical presentation, screening tests, and treatment for each micronutrient deficiency. With careful monitoring and adequate supplementation, these deficiencies are largely avoidable and treatable.