Nutrient deficiencies represent one of the major long-term complications associated with the duodenal switch (DS). Adherence to bariatric recommendations (ASMBS and AES/TOS/ASMBS) for multivitamin/mineral (MVM) supplementation are believed to help prevent nutrient deficiencies with bariatric procedures. In this study, we examine the effectiveness of compliance to bariatric MVM guidelines for prevention of nutrient deficiencies following the DS.


DS patients (n=79) were advised to take daily bariatric MVM supplements at amounts >= those recommended by ASMBS (2016) and AES/TOS/ASMBS (2019) guidelines. Vitamin and mineral levels were monitored over a 2-year postoperative period (3, 6, 12 and 24 months) and supplement intakes adjusted to treat low and deficient nutrients.


The data show albumin, iron, and Vitamins A, E, B1, B9 levels initially declined postoperatively over the first 6 months but, with early recognition and supplement adjustment, returned to, or toward, baseline. In contrast, copper and zinc levels declined progressively over time postoperatively with deficiency rates of 37% and 32%, despite daily intakes >=200% RDI and supplement correction. Vitamin D levels with daily supplement intake >=6000 IU improved at 3 and 6 postoperative months but worsened at 24 months to deficiency and insufficiency rates of 22% and 40%, respectively. Serum calcium levels progressively declined with time and PTH levels increased (35% elevated by 24 months).


Current guidelines for nutrient supplements following the DS, along with additional MVM adjustments, are effective in the prevention of most micronutrient deficiencies, with the exception of copper, zinc, calcium and vitamin D.