What type of nutritional deficiencies are caused by gastric sleeve surgery?

Nutritional Deficiencies After Gastric Sleeve Surgery

Gastric sleeve surgery commonly causes deficiencies in vitamin B12, iron, folate, vitamin D, and calcium, requiring lifelong supplementation to prevent serious health complications.

Common Nutritional Deficiencies Following Sleeve Gastrectomy

Sleeve gastrectomy (LSG) is primarily a restrictive procedure that can lead to various nutritional deficiencies due to reduced food intake, changes in food choices, and altered gastric function. While generally less severe than malabsorptive procedures like gastric bypass, these deficiencies require monitoring and supplementation.

Most Common Deficiencies

1. Vitamin B12 (Cobalamin)

   • Prevalence: Deficiency seen in up to 30% of patients preoperatively, improving to 16% at 5 years with supplementation 1
   • Mechanism: Reduced gastric acid and intrinsic factor production
   • Recommendation: 1000 μg/day sublingual or as needed to maintain normal levels 2

2. Iron

   • Prevalence: Low ferritin increases from 8.6% preoperatively to 37.8% at 5 years 1
   • Mechanism: Reduced gastric acid affecting absorption
   • Recommendation: Women of childbearing age should consume 50-100 mg elemental iron daily 2

3. Vitamin D and Calcium

   • Prevalence: Vitamin D deficiency improves from 63.2% preoperatively to 24.3% at 5 years with supplementation 1
   • Recommendation: Daily calcium intake should reach 1200-1500 mg/day from food and supplements 2
   • Note: Hyperparathyroidism persists in 20.8% of patients at 5 years 1

4. Folate (Vitamin B9)

   • Recommendation: 400 μg/day included in routine multivitamin supplement 2
   • Higher doses (800-1000 μg/day) for women planning pregnancy 2

5. Protein

   • Recommendation: 60-80 g/day or 1.1-1.5 g/kg of ideal body weight 2
   • Hypoalbuminemia increases from 1.1% preoperatively to 4.2% at 5 years 1

Less Common but Important Deficiencies

1. Thiamine (Vitamin B1)

   • Particularly at risk in early postoperative weeks with poor intake or vomiting 2
   • Recommendation: Immediate treatment if deficiency is suspected 2

2. Zinc

   • Recommendation: 15 mg/day in routine multivitamin 2

3. Vitamin A

   • Transient insufficiency peaks at 3 months (28.7%) before returning to baseline 1
   • Recommendation: 6000 IU should be included in routine multivitamin 2

Supplementation Protocol

Standard Recommendation

• Daily multivitamin: 1-2 adult doses containing all essential vitamins and minerals 2
• Calcium: 1200-1500 mg/day (single doses should not exceed 600 mg and should be separated from iron supplements by 2 hours) 2
• Vitamin D: As needed to maintain normal levels
• Iron: 50-100 mg elemental iron for women of childbearing age 2
• Vitamin B12: 1000 μg/day sublingual or as needed 2

Monitoring Schedule

• Regular nutritional screening is essential to detect and address deficiencies early
• Laboratory tests should include:
  • Complete blood count
  • Iron studies (ferritin, iron, TIBC)
  • Vitamin B12
  • Folate
  • Vitamin D and calcium
  • Albumin and prealbumin
  • Zinc and copper levels

Clinical Pearls and Pitfalls

• Preoperative deficiencies: Many patients have nutritional deficiencies before surgery that worsen afterward if not addressed 1
• Pregnancy considerations: Women should avoid pregnancy for 12-18 months after surgery and require specialized supplementation if planning pregnancy 2
• Compliance issues: Non-compliance with supplements remains a significant problem affecting long-term nutritional status 3
• Early detection: Unexplained anemia or fatigue may indicate nutritional deficiencies including protein, zinc, copper, and selenium 2
• Eating behaviors: Patients should adopt favorable eating behaviors including small frequent meals (4-6 per day), thorough chewing, and avoiding high-calorie dense foods 2

Comparison to Other Bariatric Procedures

While sleeve gastrectomy causes fewer nutritional deficiencies than malabsorptive procedures like gastric bypass, specific nutrients (particularly vitamin B12, iron, vitamin D, and calcium) still require monitoring and supplementation 4, 5. Purely restrictive procedures like sleeve gastrectomy primarily affect the absorption of iron, selenium, and vitamin B12, while more extensive procedures like gastric bypass have broader impacts on nutrient absorption 4.