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Oral Vitamin B12 following a Sleeve Gastrectomy

Date issued: September 2023

Review date: September 2025

Ref: C-543/CP/Dietetics/Oral Vitamin B12 following a Sleeve Gastrectomy

PDF:  Oral Vitamin B12 following a Sleeve Gastrectomy final September 2023.pdf [pdf] 398KB


You may have been advised that you would need to have regular injections of Vitamin B12 every 12 weeks, starting 6 months after your surgery. Recently a tablet alternative has become available which is likely to be an alternative to injections. We are proposing to use these tablets and closely monitor patients B12 levels to ensure this is a safe alternative to B12 injections.

Why do you need Vitamin B12 following surgery?

Vitamin B12 is a water-soluble vitamin that is naturally present in some foods and added to others, such as cereals and supplements.

You have been advised that following surgery, due to the reduction in food intake and reduced absorption, you may not be able to get all your daily requirements from food and therefore you need to take additional supplements to prevent deficiencies.

B12 is needed to form red blood cells and DNA.  It is also an important for the function and development of the brain and nervous system. If you do not get enough B12 this can then lead to problems with your production of red cells and neurological system.

Benefits of B12

  • Improves heart health

  • Formation of red blood cells

  • Improves energy

  • Supports bone health

  • Healthy skin, hair, and nails

  • Healthy brain

  • Improves mood

  • Supports nervous system

Symptoms of B12 deficiency?

  • Extreme tiredness

  • A lack of energy

  • Pins and needles

  • A sore and red tongue

  • Muscle weakness

  • Disturbed vison

  • Psychological problems: which may include depression and confusion

If you have any of these symptoms it does not necessarily mean you are B12 deficient. There are many other causes for these symptoms. Particularly ‘Extreme tiredness’ or ‘Lack of energy’.

How much B12 do I need a day?

The recommended daily ‘reference nutrient intake’ (RNI) of B12 is 1.5 mcg daily in the general population to help prevent deficiency.

Absorption of B12 following surgery and what we know now.

It was believed that following a Sleeve Gastrectomy you may not be able to absorb B12 into your intestine. It is now thought you will be able to absorb some B12.

We now believe that from a high dose of oral B12 tablet (1000 mcg) you will absorb 1-2% (10-20 mcg) which will meet your daily requirements. There is no danger of overdose with such a high dose, as the body will naturally dispose of excess in urine.

When will you start your oral B12 tablet?

The day after you have your surgery.

How to take your B12 Tablet ‘Orobalin’?

  • Swallow the tablet whole with a drink of water. Do not chew or break them.

  • It is best to take them on an empty stomach. This means at least 2 hrs before or after food.

What if you forget to take it?

  • Take your usual dose as soon as you remember.

  • If it is nearly time for your next dose. Don’t take the missed dose and take your next tablet as normal.

  • If you forget to take your tablets often, it may be helpful to set an alarm to remind you.

  • You may also find it helpful to put your tablet in a special medicine dispenser with all your other vitamin and mineral supplements.


It is still important that you eat foods that are high in Vitamin B12. This includes the following:

  • Meat

  • Fish

  • Eggs

  • Diary; milk, yogurt, cheese

  • Fortified breakfast cereal

  • Fortified non-diary-milk.

  • Yeast Extract such as Marmite®

Monitoring your B12 levels:

You will continue to have your B12 levels checked as part of your routine nutritional bloods at 3, 6 and 12 and 18 months after surgery, and then annually.

Advantages of oral therapy?

  • You will avoid the peak and troughs that the injection can cause

  • You won’t need to attend an appointment with your nurse every 12 weeks to have your injection

  • If you don’t like needles or having injections this will reduce your anxiety

What happens if my B12 levels are low despite taking the B12 tablets?

You will be prescribed B12 injections every 3 months instead of the tablets.

Who will be responsible for prescribing your treatment

As this is a new treatment, this will be prescribed by the Bariatric Surgical Team. It can not be prescribed by your GP. We will arrange for you to get a repeat prescription every 3 months, via Lloyds at Derriford Hospital.


As this is a new treatment, we will be collecting, monitoring, and recording your B12 levels at 3,6,12,18 months and 2 years. Your data will be anonymised and used to ensure that this treatment works well for you. Secondly, we would like to use this data to inform the decision-making process for GP’s to be able to prescribe ‘Orobalin’.        

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