ABSTRACT
BACKGROUND: Patients who undergo bariatric surgery are at risk for micronutrient deficiencies. The aims of this study were to determine the prevalence and predictors of vitamin D deficiency in obese patients residing in the northern climate, and to evaluate the effectiveness of a daily maintenance dose of vitamin D 2000 IU in preventing hypovitaminosis D within 1 year after bariatric surgery. METHODS: A cohort study involving adult patients undergoing RYGB was conducted. Longitudinal changes in serum vitamin D concentrations and clinical parameters were measured and collected. RESULTS: Data from 134 recipients of RYGB were analyzed. Hypovitaminosis D was identified in 86 patients (64 %), and was significantly affected by seasonal change and the number of comorbidities. Follow-up 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 ≥ 2000 IU. CONCLUSIONS: The prevalence of hypovitaminosis D before RYGB was comparable to patients living in the non-northern climate. Daily vitamin D intake meeting at least 2000 IU is associated with greater improvement in serum vitamin D concentration.
