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Vitamin B12 Deficiency

What is Vitamin B12 (Cobalamin)?

Vitamin B12 is a water soluble vitamin. It cannot be made synthetically, but must be grown, like penicillin, in bacteria or mould. Animal protein contains the highest level of naturally occurring B12, with liver being the best source and kidney, muscle meats, fish and dairy products being other good sources of this essential vitamin. Because of this, vegans and vegetarians have an increased risk of developing a B12 deficiency.

Vitamin B12 is unique, in that it is the first cobalt-containing substance found to be essential for longevity and it is the only vitamin that contains essential mineral elements.

Functions of Vitamin B12 in the body

Vitamin B12 is necessary for normal metabolism of nerve tissue and is involved in protein, fat and carbohydrate metabolism. It also helps iron function better in the body and aids folic acid in the synthesis of choline. B12 helps the placement of Vitamin A into body tissues by aiding carotene absorption or Vitamin A conversion. It also aids in the production of DNA and RNA, the body's genetic material. 

Absorption and Storage of Vitamin B12 in the body

Vitamin B12 is prepared for absorption by two gastric secretions. It is poorly absorbed from the gastrointestinal tract unless the "intrinsic factor", a mucoprotein enzyme, is present. Autoimmune reactions in the body can bind to the intrinsic factor, preventing vitamin B12 absorption. The intrinsic factor itself may not even be made because auto immune reactions prevent the cells ability to produce it.

A defect in the molecule that transports Vitamin B12 from the blood to the tissues can cause a deficiency - even when a normal serum blood test is read.

People who are deficient in Vitamin B12 usually lack one or more of these gastric secretions, necessary for its absorption. Many people lack the ability to absorb Vitamin B12 at all.

Better Absorption of B12

  • Calcium - Vitamin B12 needs to be combined with Calcium during absorption to benefit from this vitamin properly. 
  • Hydrochloric Acid - The presence of hydrochloric acid also aids in the absorption of B12 when given orally. This is of concern for those who take proton pump inhibitor drugs, as these medications interfere with and decrease hydrochloric acid levels. People with blue eyes will often be low in hydrochloric acid, as will those who suffer with a candida overgrowth and marijuana smokers. 
  • Apple Cider Vinegar - 1 tablespoon of apple cider vinegar, in approx 100ml of tepid water, sipped with a protein containing meal, is almost identical in composition to hydrochloric acid and will help with a better breakdown of protein. Use apple cider vinegar which contains "the mother" which shows the vinegar has not been pasteurized or heated, killing this bug. Apple cider vinegar can make a candida overgrowth much worse, so should be avoided by those ailed with this. 
  • A properly functioning thyroid gland also helps Vitamin B12 to be better absorbed. 
  • When the intake of B12 is low, 60 to 80% of the vitamin is absorbed. When high amounts of Vitamin B12 are taken, the absorption decreases from 50 to 10 percent. Absorption of B12 is better when is it taken with several meals, rather than just one.
  • After its absorption, Vitamin B12 is bound to serum protein (globulin's) and is transported in the bloodstream to various tissues of the body.
  • The absorption of B12 appears to decrease with age, as well as with iron, calcium and Vitamin B6 deficiencies. Absorption of Vitamin B12 increases during pregnancy. Because of its close relationship with folic acid, both vitamins taken together could be of benefit in many cases.
  • The use of laxatives depletes the storage of Vitamin B12.

The highest concentrations of Vitamin B12 in the body are:

The highest concentrations of B12 in the body are found in the liver, kidneys, heart, pancreas, testes, brain, blood and bone marrow. These body members are all related to red blood cell formation.

Causes of a Vitamin B12 deficiency

A deficiency of Vitamin B12 is usually caused by an absorption problem caused by a lack of the intrinsic factor.

In those who have prolonged gastritis, a condition where the mucous lining of the stomach becomes irritated and inflamed, the stomach walls become very thin, secreting almost entirely mucus and very little digestive acid. In this condition, the stomach is unable to produce the intrinsic factor, a mucoprotein enzyme, necessary for the absorption of Vitamin B12 - which is essential for the formation of red blood cells. Because of this, a gastritis sufferer is in danger of developing pernicious anaemia.

A vitamin B12 deficiency can also be the result of parasites, such as a fish tapeworm.

A lack of B12 can also be caused by an excessive overgrowth of bacteria in the stomach and intestines.

Symptoms of Vitamin B12 Deficiency

Symptoms of a Vitamin B12 deficiency:

  • May take 5 or 6 years to appear, after the body is restricted from its supply of this vital nutrient
  • Symptoms begin with changes in the nervous system such as soreness and weakness in the legs and arms, diminished reflex response and sensory perception, difficulty in walking and speaking (stammering) and jerking of limbs.
  • A lack of B12 has been found to cause a type of brain damage resembling schizophrenia. This brain damage may be detected by these symptoms: Sore mouth, numbness or stiffness, a feeling of deadness, shooting pains, pins and needles, or a hot and cold sensation. The British Medical Journal (March 26 1966) stated editorially, "It is true that vitamin B12 deficiency may cause severe psychotic symptoms which may vary in severity from mild disorders of mood, mental slowness and memory defect to severe psychotic symptoms...occasionally, these mental disturbances may be the first manifestation of B12 deficiency. 
  • Other symptoms of Vitamin B12 deficiency may include nervousness, neuritis, unpleasant body odour, menstrual disturbances and difficulty in walking.
  • If a deficiency is not detected in early stages, it may result in permanent mental deterioration and paralysis. When symptoms become serious do not try and treat them yourself. Seek medical attention. 

Pernicious Anaemia and Vitamin B12 Injections

Pernicious anaemia is a condition characterised by insufficient red blood cells in the bone marrow. Pernicious anaemia probably arises from an inheritable inability of the stomach to secrete intrinsic factor, necessary for the intestinal absorption of vitamin B12.

Injections, rather than an oral dose of Vitamin B12 is given, to bypass the absorption defect. B12 helps the red blood cells to mature up to a certain point, and after than, protein, iron, vitamin A and folic acid help to finish the development of the cells so that they can mature.

Vegetarians and Vegans are particularly susceptible to this type of anaemia, due to their lack of animal protein consumption. In addition to this, the high level of folic acid contained in a vegetarian diet can mask a B12 deficiency.

Symptoms of pernicious anaemia include:

Weakness and gastrointestinal disturbances causing a sore tongue, slight yellowing of the skin and tingling of the extremities.

In addition, disturbances of the nervous system such as partial loss of coordination of the fingers, feet and legs, some nerve deterioration and disturbances of the digestive tract such as diarrhoea and loss of appetite may occur.

Vitamin B12 and Homocysteine levels

Homocysteine is a sulphur-containing amino acid, present in the cells of our body, generally in only small amounts. Homocysteine is a product of methionine metabolism. Methionine is one of the eleven "essential" amino acids in the body. In healthy cells, homocysteine is quickly converted to other products.

Vitamins B6, B12, and folic acid are necessary to metabolize homocysteine. People who are deficient in these vitamins may have increased levels of homocysteine.

Some information states that high levels of homocysteine cause nerve and blood vessel damage, promoting the risk of a stroke and cardiovascular disease.  Supplementation with Vitamin B12, B6 and Folate can help to lower these levels. 

Homocystinuira is a disorder caused by an alteration to 1 or more genes, preventing the normal breakdown of methionine in the body. Because of this, homocysteine and methione levels increase in the body. A baby with homocystinuira will appear normal at birth but within a few years will begin to develop signs such as a dislocated lens in the eye, a long slender build, long thin fingers, skeletal abnormalities, osteoporosis, and a greatly increased risk of thromboembolism and of atherosclerosis that can lead to premature cardiovascular disease. The buildup may also cause progressive mental retardation, behavioral disorders, and seizures.

Vitamin B12 sources

Rich sources of Vitamin B12 include:

  • Organ meats (especially liver), fish, pork, eggs, cheese, milk and dairy products
  • Pipis, a shellfish dug for at a low tide on New Zealand beaches, contains the highest amount of Vitamin B12 next to liver. 100 grams of Pipis contain around 62mcg of Vitamin B12, compared to 100 grams of beef liver, which contains around 110mcg.
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The Naturopathic Team
Ideal Health

Disclaimer: The health information presented here has been written for the New Zealand health consumer. It is of a general nature and is only intended to provide a summary of the subjects covered and is intended to be used for educational and general information purposes only. It is not intended as medical advice or as a means to diagnose, treat, cure or prescribe for any particular condition or disease. You assume all responsibility for the treatment which may be undertaken as a result of the information on this site, or treatment recommended by any other party. While all care has been taken to ensure the accuracy of the information, no responsibility or liability is accepted, and no person should act in reliance on any statement contained in the information provided. All health ailments should be treated by a qualified health professional.

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