Zinc Deficiency after Gastric Bypass for Morbid Obesity: a Systematic Review

Up to 50% of patients have zinc deficiency before bariatric surgery. Roux-en-Y gastric bypass (RYGB) is the commonest bariatric procedure worldwide. It can further exacerbate zinc deficiency by reducing intake as well as absorption. The British Obesity and Metabolic Surgery Society, therefore, recommends that zinc level should be monitored routinely following gastric bypass. However, the American guidance does not recommend such monitoring for all RYGB patients and reserves it for patients with 'specific findings'. This review concludes that clinically relevant Zn deficiency is rare after RYGB. Routine monitoring of zinc levels is hence unnecessary for asymptomatic patients after RYGB and should be reserved for patients with skin lesions, hair loss, pica, dysgeusia, hypogonadism or erectile dysfunction in male patients, and unexplained iron deficiency anaemia.