Vitamin B12

Continuing our series on various nutrients we are going to have a look at Vitamin B12. This is relevant for all types of surgery but particularly if the stomach is reduced in size ie the gastric bypass and sleeve. From a dietary point of view Vitamin B 12 is found in meat, some fish, milk, dairy and eggs. These are often foods that people find mechanically difficult to eat after surgery or you can become intolerant to. As well as this we produce a substance in our stomachs called intrinsic factor which helps to absorb the vitamin in the gut. Less stomach means less intrinsic factor.

Vitamin B12 (also known as cobalamin) is vital to all cells in the human body

Symptoms of deficiency are listed below, some of these are irreversible so it is important that supplements are taken and a balanced diet followed-

Brain fog
Poor concentration
Short term memory loss
Confusion eg putting your purse in the fridge
Forgetting names of objects

Shortness of breath (the sighs)

Clumsiness / lack of coordination

Brittle, flaky nails, dry skin

Mood swings


Numbness/ tingling- especially in hands, arms. Legs, feet.

Extreme Fatigue

Feeling the cold all the time

The British Obesity and Metabolic Surgery nutritional guidelines recommend people who have had a gastric bypass, gastric sleeve and BPD/DS should have 3 monthly Vitamin B12 injections.

Blood levels of Vitamin B12 should be checked at least annually and should stay above 200µg and ideally between 800-900µg.

Meat, fish, and dairy foods are all good sources of vitamin B12. Fortified breakfast cereals, soya products, and yeast extract are also good source of vitamin B12 and may be good options for vegetarians. Vitamin B12 is the only vitamin that is not found in vegetable.

Disclaimer: Please note that weight loss surgery results and benefits are unique to each individual and in such The Bariatric Group cannot guarantee specific weight loss goals as results for each surgery can vary. If you have any questions or would like to know more about weight loss surgery please contact our expert team.