B12 and folate deficiency

B12 and Folate are two separate vitamins which are part of the B complex group. They are also known as cobalamin and B9 respectively.


Sources of folate:

  • offal
  • yeast
  • peas
  • citrus fruits
  • green leafy vegetables
  • dry beans.

Sources of B12:

  • eggs
  • milk
  • poultry
  • fish
  • red meat.

What is B12 or folate deficiency anaemia?

Our red blood cells, also known as haemoglobin, carry oxygen throughout the body. If there is a low number of haemoglobin cells, or they are not correctly developed, the amount of oxygen our bodies can transport reduces. B12 plays a vital role in the formation of red blood cells, the production of energy, DNA and the processing of essential fatty acids. So it is clear that reduction in absorption can affect many of our body's functions. Memory, mood, digestion, activity levels, motivation, behaviour, energy, growth and repair can all be affected by the deficiency.

Pernicious anaemia (autoimmune) is the most common cause of B12 deficiency here in the UK. Autoimmune conditions mean your body’s own defence system turns on itself, attacking healthy cells. Pernicious anaemia affects the stomach by attacking the stomach cells which enable us to absorb B12 by producing a substance called intrinsic factor. The reduction of intrinsic factor through poor absorption can cause autoimmune conditions such as Addison’s and even vitiligo.

A poor diet can lead to B12 deficiency. A varied diet with plenty of meats, green vegetables and dairy products provides ample B12. However, there are some eating regimens which eliminate some of these food groups. Vegans are an example of this and they may be at risk of deficiency.

'Fussy eaters' or lifestyle/mental difficulties/autistic spectrum are some of the reasons why B12 deficiency can creep in. 

Gastric surgery such as gastrectomy or even a gastric band can lead to reduced absorption of B12.

Crohn's disease can lead to severe inflammation in the digestive system. This inflammation can in turn lead to B12 deficiency through lack of absorption.

Acid reflux is sometimes treated with Proton Pump Inhibitors (PPIs) which are medications which reduce the amount of stomach acid the body produces. This action reduces the stomach’s ability to release B12 from food.

Interestingly, B12 takes up to four years to deplete in the body, so it cannot always logically be linked to lifestyle changes.

Folate deficiency

Folate is water-soluble, so is not stored efficiently. The body usually has an average of four months’ supply before deficiency creeps in. It is therefore essential to eat a varied diet including folate-rich foods to ensure availability.

Poor diet, for the same reasons as B12 deficiency, (fussy eating, eating fad, poor health, alcohol abuse and certain medications) can lead to deficiency.

Excessive urination as a result of heart failure, liver damage, and dialysis can cause too much loss of folate.

Medications can inhibit absorption and your GP will be aware of this. The datasheet that comes with the medication may also indicate if this is the case. If you are unsure it is advisable to check with a medical professional, pharmacist or the prescribing practitioner.

If a supplement is necessary, a nutritionist can advise on the correct dose. Also, you may be able to improve your diet to increase B12 and folate although this is subject to contra-indicating conditions or medications as mentioned above.

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

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Faversham ME13 & Folkestone CT19
Written by Victoria Shorland, Nutritionist, Allergy Testing, Phlebotomist, Faversham, Kent
Faversham ME13 & Folkestone CT19

Victoria runs her clinic from Faversham and Hythe Kent, and also works with Spire Hospitals.
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