Nutritional Deficiencies Following Bariatric Surgery: A Rapid Systematic Review of Case Reports of Vitamin and Micronutrient Deficiencies Presenting More Than Two Years Post-Surgery.

Bariatric surgery is the most clinically- and cost-effective intervention for severe obesity. However, without adequate follow-up, it can lead to nutritional deficiencies. Patients require life-long nutritional supplements and follow-up to prevent nutritional deficiencies from developing. This rapid systematic review is the first synthesis of case reports of patients with vitamin and micronutrient deficiencies at least 2 years following bariatric surgery, the point at which patients are typically discharged from specialist bariatric services. Eighty-three cases (74 studies) met inclusion criteria. Female patients accounted for 84% of the reports. Roux-en-Y Gastric Bypass (RYGB) was the most common procedure to have been performed, followed by biliopancreatic diversion (BPD). The most frequently reported deficiencies were vitamin A (n = 15), copper (n = 14) and vitamin D (n = 23). In some cases, vitamin replacement led to symptom resolution, but some preceded permanent disability or death. Fifty-one case reports detailed factors contributing to the development of the deficiency. These could be divided into patient factors or health care factors and provide areas to target interventions, including support to adhere to supplementation, appropriate follow-up, and health professional awareness.