From the Guidelines
After gastric bypass surgery, patients typically need lifelong supplementation with a daily multivitamin, calcium citrate (1200-1500 mg daily), vitamin D (3000 IU daily), vitamin B12 (250-350 μg daily orally or 1000 μg monthly as injections), and iron (45-60 mg elemental iron daily) to prevent nutritional deficiencies and maintain optimal health, as recommended by the most recent and highest quality study 1.
Key Supplements and Their Importance
- A daily multivitamin is essential to fill any nutritional gaps and prevent deficiencies, as the surgery can lead to reduced absorption of nutrients 1.
- Calcium citrate is crucial for bone health, and the recommended dose is 1200-1500 mg daily, which should be taken in divided doses to maximize absorption 1.
- Vitamin D supplementation is necessary to maintain optimal levels, with a recommended dose of 3000 IU daily, titrated to achieve normal concentrations of 30 ng/mL 1.
- Vitamin B12 supplementation is vital, as the bypassed portion of the stomach produces intrinsic factor, necessary for B12 absorption, and the recommended dose is 250-350 μg daily orally or 1000 μg monthly as injections 1.
- Iron deficiency is common, especially in menstruating women, and supplementation with 45-60 mg elemental iron daily is necessary to prevent anemia 1.
Additional Recommendations
- Patients should also consider taking fat-soluble vitamins (A, K, and E) and other essential nutrients, such as thiamin, folic acid, zinc, and copper, as part of their daily multivitamin or separate supplements 1.
- It is essential to take these supplements at different times of the day to maximize absorption and have regular blood tests to monitor nutrient levels and adjust supplementation as needed 1.
- A balanced diet with high-protein foods and limited high-calorie, high-sugar, and high-fat foods is also crucial for maintaining optimal health and preventing nutritional deficiencies after gastric bypass surgery 1.
From the Research
Recommended Supplements After Gastric Bypass Surgery
The following supplements are recommended after gastric bypass surgery:
- Thiamine
- Vitamin B₁₂
- Vitamin D
- Iron
- Copper
- Folic acid
- Calcium
Rationale for Supplement Recommendations
These supplements are recommended due to the high risk of nutrient deficiencies after gastric bypass surgery, as reported in several studies 2, 3, 4, 5, 6. The most common clinically relevant micronutrient deficiencies after gastric bypass include thiamine, vitamin B₁₂, vitamin D, iron, and copper.
Key Findings from Studies
- A study published in 2013 found that diet and multivitamin use are unlikely to consistently prevent deficiency, thus supplementation with additional specific nutrients is often needed 2.
- A 2019 study reported that iron and calcium/vitamin D deficiency occur in up to 50% of patients following Roux-en-Y Gastric Bypass (RYGB) 3.
- A randomized controlled trial published in 2014 found that an optimized multivitamin supplement can lower postoperative deficiencies, including iron and vitamin B₁₂ deficiencies 4.
- A 2015 study emphasized the importance of preoperative assessment and treatment of nutritional deficiencies in morbidly obese patients undergoing gastric bypass surgery, as preoperative deficiencies can increase the risk of postoperative deficiencies despite supplementation 5.
- A systematic review published in 2018 found that oral vitamin B₁₂ supplementation doses of ≤ 15 μg daily are insufficient to prevent deficiency in RYGB patients, but doses of 1000 μg vitamin B₁₂ daily might be adequate 6.
Supplement Dosages
The optimal supplement dosages are not yet defined, but the following dosages have been suggested: