Key visual gastric bypass deficiency guideline

Guideline to prevent and treat nutritional deficiencies after Roux-en-Y Gastric Bypass

The Roux-en-Y Gastric Bypass is commonly associated with nutritional deficiencies and requires life-long supplementation. To bring guidance into nutritional healthcare for this patient group, a literature review was conducted. This review lead to a new approach to prevention and management of nutritional deficiencies and a guideline for supplementation after a Gastric Bypass.

Guideline on supplementation dosages

The review found that the prevention strategy for every Gastric Bypass patient should include a multivitamin containing at least 200% of the daily recommended value, 400 mcg of folic acid and 18 mg of iron. Furthermore, vitamin A, vitamin B12, vitamin D, calcium, zinc and copper should be supplemented in a dosage tailored to the patients’ specific needs. For a complete overview of dosage advice in the guideline on supplementation after a Gastric Bypass, see table 1.

Monitoring on deficiencies after a Gastric Bypass

Some bariatric patients may require additional supplementation of one or more vitamins and minerals. Patients should be monitored carefully and frequently. To ensure optimal deficiency prevention and treatment, patients should be made aware of the importance of proper nutrition and compliance with supplementation.


Table 1: Prevalence and advice for nutritional deficiencies after a Gastric Bypass

Nutrient Deficiency prevalence Supplementation advice for deficiency prevention
Vitamin B12 26-70% 1000 mcg orally or sublingually
Folate 9-38%, higher prevalence among pregnant women 800-1000 mccg
Iron 6-52%, higher prevalence among menstruating or pregnant women 36-65 mg, higher doses for menstruating women and people at risk for anemia
Thiamine 1% 3 mg
Calcium 10% 2 years post-op 1.700-2.000 mg from both diet and supplementation
Vitamin D 50-80% 1.000-2.000 IU
Vitamin A 11% 10.000-25.000 IU
Zinc 36% More research needed to identify the optimal supplementation dose
Copper 18,8% No current recommendations

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Comparing deficiency prevalence after Sleeve Gastrectomy to prevalence after Roux-en-Y Gastric Bypass

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Levinson, R., Silverman, J.B., Catella, J.G. et al. (2013) Pharmacotherapy prevention and management of nutritional deficiencies post Roux-en-Y gastric bypass. OBES SURG (2013) 23: 992.

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