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Nutritional Deficiencies in Obesity and After Bariatric Surgery

Stavra A Xanthakos, MD, MSPediatric Clinics of North America

October 200956(5): 1105-1121

Background

Research has shown micronutrient deficiencies common in obese individuals Suspected mechanisms :

Nutrient dense food sources displaced by high-calorie nutrient poor foods and beverages

These deficiencies are exacerbated with bariatric surgery

Critical to establish baseline nutritional status prior to bariatric surgery

Purpose

Present latest information regarding nutritional deficiencies in obese individuals

Discuss common post-bariatric surgery nutritional deficiencies

Review screening and supplementation to address deficiencies

Bariatric SurgeriesMalabsorptive and Restrictive

Carry the greatest risk of malnutrition Roux-en-Y gastric bypass (RYGB) – most common Biliopancreatic Diversion with duodenal switch (BPD-DS) Biliopancreatic Diversion (BPD) –rarely performed

The risk increases as more of the small intestine is bypassed Nutrients absorbed in the Proximal Small Intestine:

Vitamin D Calcium Cooper Iron

Bariatric SurgeriesPurely Restrictive

Deficiencies primarily due to limited intake Vertical Banded Gastroplasty (VBG) Adjustable Gastric Band (AGB) Vertical Sleeve Gastrectomy (VSG)

Mechanical digestion and acid production are impaired with gastric resection or bypass The result is a decline in the absorption/digestion of:

Iron, B12, Protein-bound nutrients Production of intrinsic factor also is negatively impacted

Post Bariatric Surgery

Very low caloric intake typical for 6 months after surgery Results in reduced intake of ALL macronutrients

Particularly protein Studies have shown in some cases to be as low at 0.5 g/kg

Most common symptoms of micronutrient deficiency: Anemia – up to 75% of all patients Neurological Dysfunction – 5-9%

Micronutrient Deficiencies

Prevention Research is complicated due to: Currently no standard for supplementation post

surgery Variable adherence to supplementation regime

makes determining efficacy difficult

Supplementation

General supplement recommendation 1 daily multivitamin w/folic acid – AGB & VSG 1-2 daily multivitamin w/folic acid – RYGB 2 daily multivitamin w/folic acid – BPD-DS

Supplements should be not be Enteric-coated or time-released

Liquid, Suspension, or Chewable supplements are recommended Liquid and chewable advisable for the 1st month post surgery

Iron

Most common deficiency post-surgery : 12-47% Baseline Deficiency: 44% Primary symptom: Microcytic Anemia Biomarker: Serum, Ferritin, Total Iron Binding Capacity,

CBC Supplementation: 65 mg elemental iron for

menstruating women (RYGB & BDP-DS)

Vitamin D and Calcium

Baseline Vitamin D Deficiency: 25-80% Post-surgery: serum calcium typically normal while parathyroid

hormone frequently elevated Primary symptom: Decreased bone mineral density,

secondary to hyperparathyroidism Biomarker: Serum 25-OH-D, calcium, phosphorus, PTH Supplementation:

Calcium citrate w/Vit D3: 1200-1500 mg/day –AGB 1800 mg/day-RYGB, BDP-DS

Vit D3: 1000 IU/day-RYGB 2000 IU/day BDP-DS

Fat Soluble Vitamins

Deficiency more common in BPD-DS due to fat malabsorption Baseline deficiencies:

Retinal and beta-carotene - 12.5 % Vitamin E - 23%

Biomarker: Vitamin A: plasma retinal Vitamin E: plasma alpha-tocopherol Vitamin K: prothrombin time

Supplementation: for BPD-DS – 10,000 IU vit A and 300 μg vit K

Vitamin B12

Most common following RYGB – 33% Baseline deficiency: 18% Primary symptom: anemia, neurological

dysfunction, visual loss Biomarker: Serum vitamin B12

Supplementation: Crystalline 500μm/day - sufficient for 80-95% of post-

RYGB patients 1000μm/day intramuscularly if oral not effective

Vitamin B1

Asymptomatic deficiency post-surgery:18% Baseline Deficiency: 29% Primary symptom: Opthalmoplegia, nystagmus,

ataxia, encephalopathy, rapid visual loss (Wernicke encephalopathy)

Biomarker: Serum thiamine

Folate

Folate deficiency rare pre or post surgery Regular supplementation is sufficient Deficiency may indicate noncompliance with

supplementation Primary symptom: Anemia Biomarker: Red blood cell folate, plasma

homocysteine

Vitamin C

Post-surgery deficiency (RYGB): 34.5% Baseline deficiency: 36%

Deficiency correlated with elevated BMI No adverse effects of deficiency noted to date Some studies have shown vitamin C to lower markers of

inflammation Standard supplementation is sufficient to address deficiency

Zinc, Selenium, Cooper

Post surgery zinc deficiency: 36-51% Most cases asymptomatic Non-compliant supplementation can result in: Acrodermatitis

enteropathic-like rash Base-line zinc deficiency: 28% Selenium deficiency can result in Cardiomyopathy Copper deficiency

Screen for if unexplained anemia persists and with prolonged zinc supplementation

Recommendations for Screening

Baseline, 6 months post surgery and then annually: Vitamin B1 and B12

Folate Iron Vitamin D Protein

Screen if symptoms present: B6, Copper, Zinc Those undergoing BPD or BPD-DS should also be screened

annually for: Vitamin A, E, K