Monitoring for micronutrient deficiency after bariatric surgery-what is the risk?

BACKGROUND: Bariatric surgery may increase the risk of micronutrient deficiencies; however, confounders including preoperative deficiency, supplementation and inflammation are rarely considered. OBJECTIVE: To examine the impact of bariatric surgeries, supplementation and inflammation on micronutrient deficiency. SETTING: Two public hospitals, Australia. METHODS: Participants were recruited to an observational study monitoring biochemical micronutrient outcomes, supplementation dose, inflammation and glycaemic control, pre-operatively and at 1-3, 6 and 12 months after gastric bypass (GB; Roux-en-Y Gastric Bypass and Single Anastomosis Gastric Bypass; N = 66) or sleeve gastrectomy (SG; N = 144). Participant retention at 12 months was 81%. RESULTS: Pre-operative micronutrient deficiency was common, for vitamin D (29-30%), iron (13-22%) and selenium (39% GB cohort). Supplement intake increased after surgery; however, dose was <50% of target for most nutrients. After SG, folate was vulnerable to deficiency at 6 months (OR 13 [95% CI 2, 84]; p = 0.007), with folic acid supplementation being independently associated with reduced risk. Within 1-3 months of GB, three nutrients had higher deficiency rates compared to pre-operative levels; vitamin B1 (21% vs. 6%, p < 0.01), vitamin A (21% vs. 3%, p < 0.01) and selenium (59% vs. 39%, p < 0.05). Vitamin B1 deficiency was independently associated with surgery and inflammation, selenium deficiency with improved glycaemic control after surgery and inflammation, whilst vitamin A deficiency was associated with inflammation only. CONCLUSION: In the setting of prophylactic post-surgical micronutrient prescription, few nutrients are at risk of de novo deficiency. Although micronutrient supplementation and monitoring remains important, rationalising high-frequency biochemical testing protocols in the first year after surgery may be warranted.

Does Bariatric Surgery Cause Vitamin A, B1, C or E Deficiency? A Systematic Review.

BACKGROUND: The restrictive and/or malabsorptive nature of bariatric surgery may increase the risk for micronutrient deficiencies. This systematic review aimed to identify and critique the evidence for vitamin A, B1, C or E deficiencies associated with bariatric surgery. METHODS: This review utilised PRISMA and MOOSE frameworks with NHMRC evidence hierarchy and the American Dietetic Association bias tool to assess the quality of articles. RESULTS: Twenty-one articles were included and once critiqued all studies were of level IV grade and neutral or negative in quality. The relevance of measuring micronutrient supplementation and inflammatory markers for validity of serum vitamins is absent within the literature. CONCLUSIONS: Future research is needed to investigate the risk of deficiency for these procedures with focus on confounders to serum micronutrients.