Vitamin B12 deficiency- the symptoms & causes
What are B vitamins?
- Vitamins are substances that occur naturally in food, and are needed for many essential body functions.
- There are 13 vitamins required by our body- and 8 of these are types of Vitamin B.
- There is a large industry in the sale of vitamins to the public- with promises of numerous health benefits. Some of these claims may be accurate, others may be exaggerated or simply untrue.
- The B Vitamins do have a wide variety of important roles in the body, particularly in relation to growth, repair and energy production.
- Whilst most healthy people who eat a broad and balanced diet will get enough B vitamins from their food, occasionally deficiencies can occur.
- B12 Deficiency may occur due to inadequate amounts in the diet, an inability to absorb the vitamin, or if the body is using it up more quickly than usual (e.g. in pregnancy).
What does Vitamin B12 do?
- Vitamin B12 (also known as Cobalamin) is important in the production of myelin- a protein which surrounds nerves and allows messages to travel efficiently along the nerves.
- Vitamin B12 also has vital roles in brain function, blood cell formation, DNA production and energy production in the body.
How much Vitamin B12 do you need?
- The recommended dietary allowance (RDA) of Vitamin B12 is 2.4 μg/day, though slightly more is needed by women who are pregnant or breastfeeding.
- Good sources of B12 include meat, milk, eggs, cheese, yeast extracts and fortified breakfast cereals
- B12 is the only vitamin not found in vegetables
What causes Vitamin B12 deficiency?
It’s not always clear why some people get Vitamin B12 deficiency. It is certainly seen more commonly in older people. It can also relate to one or more of the following issues:
- Low B12 intake- e.g due to a vegetarian or vegan diet
- Pernicious Anaemia- an autoimmune condition which results in poor absorption of Vitamin B12 by the stomach
- The contraceptive pill
- Other medications such as Metformin and certain antacids.
- Chronic Alcoholism
- Pancreatic failure
- Pregnancy ( as the body is using up more Vitamin B12 than usual)
- Babies born to mums who have low B12 or who are vegan
- Coeliac disease
- A history of surgery on the stomach or small bowel
- Inflammatory bowel disease (such as Crohn’s disease)
- Blind loop syndrome or small bowel bacterial overgrowth
- Infection with fish tapeworm (more common in countries where raw fish is widely eaten)
How is Vitamin B12 deficiency diagnosed?
- Your doctor can check your Vitamin B12 levels by requesting a blood test.
- A full blood count (FBC) may be done, as anaemia is a complication of low B12.
- Folate levels tend to be assessed with B12, as folate and B12 have closely related roles in the body.
- If B12 is low, Autoimmune antibodies may be measured to check for Pernicious Anaemia
- A test for coeliac disease may also be recommended.
What is the treatment for Vitamin B12 deficiency?
- Obviously, any underlying causes such as medications, dietary issues or bowel problems should be identified and treated.
- Quite often a course of B12 injections will be prescribed by your doctor, as this will restore levels to normal quickly- this method will work even if a person has an inability to absorb B12 properly, as it bypasses the stomach and gut.
- If Vitamin B12 deficiency is mild, oral treatment may be tried, with Vitamin B12 tablets ( though this method may not work if your stomach and gut are not absorbing it properly).
- It may also help to obtain more B12 in your diet by sourcing foods high in B12- e.g. meat, milk, eggs, cheese, yeast extracts and fortified breakfast cereals.
- It’s important to discuss follow-up with your doctor- you may need to have your levels rechecked after treatment to ensure they do not drop again.
For more information on Vitamin B12 deficiency speak to your doctor or pharmacist.