Clinical outcomes following pre- and post-operative vitamin D supplementation in Roux-en-Y Gastric Bypass patients

Abstract

<bold>Background:</bold> Bariatric surgery is associated with risks for micronutrient deficiencies. For example, hypovitaminosis D (25(OH)D ≤30ng/mL) has been reported in obese individuals and patients who received Roux-en-Y gastric bypass (RYGB). Investigations on incidence of hypovitaminosis D in patients undergoing bariatric surgery in the Pacific Northwest are limited. The primary aim of this study was to identify the incidence of hypovitaminosis D in patients prior to RYGB. The relationship between 25(OH)D status and patient characteristics (age, gender, ethnicity, BMI, comorbidities) was analyzed. The secondary aim was to analyze longitudinal change in 25(OH)D concentration 1 year post-operatively. <bold>Methods:</bold> A cohort study involving adult patients undergoing RYGB was conducted. Longitudinal change in serum vitamin D concentrations and clinical parameters were collected. <bold>Results:</bold> Baseline data were analyzed in 134 patients. Hypovitaminosis D was identified in 90 patients (incidence of 67%), and was significantly affected by seasonal change and the number of comorbidities. Longitudinal data were available in 60 patients. Vitamin D sufficiency was achieved in 62.5% of those patients with baseline vitamin D insufficiency. A dose-response relationship of vitamin D intake was observed, with the most significant increase in 25(OH)D associated with daily vitamin D intakes ≥2000IU. <bold>Conclusions:</bold> A significant number of patients have hypovitaminosis D at baseline. Daily vitamin D intake meeting at least 2000IU is associated with greater improvement in serum vitamin D concentration.