Prevalence of nutrient deficiencies in bariatric patients

Abstract 

Objective

The aims of this study were to determine the prevalence of nutrient deficiencies in patients who present for bariatric surgery, assess nutritional status after surgery, and compare these with preoperative levels.

Methods

A retrospective study was conducted to identify preoperative and 1-year postoperative nutrition deficiencies in patients undergoing bariatric surgery. The screening included serum ferritin, vitamin D, vitamin B₁₂, homocysteine, folate, red blood cell folate, and hemoglobin. Results were available for 232 patients preoperatively and 149 patients postoperatively. Two-tailed χ² tests and paired-sample t tests were used.

Results

Preoperatively, vitamin D deficiency was noted at 57%. The prevalence of abnormalities 1 year after roux-en-Y gastric bypass was higher compared with preoperative levels (P < .05). After surgery, anemia was detected in 17%, elevated homocysteine levels (women only) in 29%, low ferritin in 15%, low vitamin B₁₂ in 11%, and low RBC folate in 12%. Mean hemoglobin, ferritin, and RBC folate levels deteriorated significantly but remained well within normal ranges. The prevalence of vitamin D deficiencies decreased, but not significantly. In sleeve gastrectomy patients, mean ferritin levels decreased (P < .05), without any patient developing a deficiency.

Conclusion

Vitamin D deficiency is common among morbidly obese patients seeking bariatric surgery. Because the prevalence of micronutrient deficiencies persists or worsens postoperatively, routine nutrition screening, recommendation of appropriate supplements, and monitoring adherence are imperative in this population.

Keywords: Obesity, Bariatric surgery, Roux-en-Y gastric bypass, Sleeve gastrectomy, Gastric banding, Nutrient deficiency, Vitamin D