Micronutrient deficiencies and bariatric surgery

Purpose of reviewBariatric surgery is associated with the development of several micronutrient deficiencies that are predictable, preventable and treatable based on the surgically altered anatomy and imposed dietary changes. With an increasing number of severely obese patients undergoing bariatric surgery, clinicians need to become familiar with the surgical procedures and associated nutritional deficiencies. This article will review the pathophysiology, clinical presentation, screening tests, and treatment for selected micronutrient deficiencies. Recent findingsThe 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 silicone gastric banding. Although other micronutrients have been reported, the metabolic and clinical deficiencies of two minerals (iron and calcium) and four vitamins (thiamine, folate, vitamin B12 and vitamin D) have been most frequently described in the literature. Subclinical and clinical presentation of deficiencies can occur from weeks to years following the surgical procedures. Metabolic bone disease is the most concerning long-term nutritional complication. SummaryAll patients undergoing restrictive–malabsorptive procedures must be evaluated for development of micronutrient deficiencies. With careful monitoring and adequate supplementation, these deficiencies are largely avoidable and treatable.