Bariatric Surgery and Vitamin B12, what do I need to know?

 

Vitamin B12 deficiency can be a complication after bariatric surgery.

Malabsorptive surgeries such as the gastric bypass and the duodenal switch (rarely performed in the UK) are at higher risk of deficiency.

Vitamin B12 is often prescribed after bariatric surgery to prevent deficiency.

Vitamin B12 is absorbed in the small intestine. The lining of the mouth is also capable of absorbing vitamin B12 from food, but it is a small insignificant amount.

The stomach produces a glycoprotein called intrinsic factor which is essential for the absorption of vitamin B12 in the small intestine.

Why is vitamin B12 needed?

Vitamin B12 helps keep the body’s nervous system and blood cells healthy. Vitamin B12 also helps prevent megaloblastic anaemia.

Deficiency of vitamin B12 occur after bariatric surgery

Bariatric surgeries either reduce the size of the stomach or lessen the absorption of nutrients or both.

In Gastric Sleeve surgery the reduced size of the stomach results in a decrease in ghrelin (the hunger hormone) and reduced food intake.

There is also reduced production of an intrinsic factor which is needed for vitamin B12 absorption.

In Gastric Bypass surgery, the part of the stomach where the intrinsic factor is produced is avoided and never exposed to food.

When does deficiency of vitamin B12 occur?

The liver can store up to 3 years requirement of vitamin B12, so deficiency does not usually happen early after bariatric surgery.

Studies show that a significant number of patients become symptomatic within 1-2 years of gastric bypass surgery if not supplemented with Vitamin B12. Vitamin B12 injections are usually prescribed every 3 months for life following Bariatric Surgery. There are other forms of vitamin B12 available (sub lingual and nasal spray.) You should discuss this with your bariatric surgeon or bariatric dietitian.

 

Signs and Symptoms of vitamin B12 deficiency:

 

  • Feeling Weak
  • Fatigue
  • Dizziness
  • Loss of appetite
  • Diarrhoea
  • Painful swollen tongue
  • Pins and Needle sensations in the hands and feet
  • Nerve damage
  • Abnormal heart function
  • Poor Memory

 

Vitamin B12 supplementation is important after bariatric surgery, especially those patients who have had Gastric bypass surgery.