Preoperative Nutritional Deficiencies in Bariatric Surgery Candidates in Korea

Background All bariatric surgical procedures may compromise the nutritional status of patients, but nutritional deficiencies vary by region and culture. However, there are no preoperative nutritional guidelines for bariatric patients in East Asia. Here, we aimed to evaluate the preoperative nutritional status of East Asian bariatric surgical patients. Methods We performed a retrospective cohort study of 215 consecutive patients who underwent bariatric surgery between January and December 2019 at a single tertiary institution in Korea. Medical background evaluation, anthropometric measurements, and laboratory tests were performed before surgery. Results Vitamin D deficiency was identified in 80.0% of participants and 13.8% had insufficiency. The prevalence of vitamin D deficiency or insufficiency and the mean vitamin D concentration did not significantly differ between the sexes. Vitamin B1 (thiamine) deficiency was the second most common deficiency (18.3%), followed by folate (14.2%), iron (11.8%), and zinc (7.6%) deficiencies. The prevalence of anemia did not significantly differ between the sexes (1.3% in men vs. 7.4% in women, p=0.10), but the prevalence of iron deficiency was significantly higher in women (1.3% vs. 17.9%, p<0.001). The prevalences of copper (2.3%) and selenium (3.2%) deficiencies were low, and none of the participants had vitamin B12 or magnesium deficiency. Conclusion There were high prevalences of vitamin D, folate, vitamin B1, and iron deficiencies in bariatric patients in Korea. Nutritional deficiencies should be corrected prior to surgery to prevent subsequent further depletion. Routine analysis of vitamin B12, magnesium, copper, and selenium before surgery should be considered and studied in more detail.