Vitamin B12: Cobalamin

Vitamin B12: Cobalamin

Authored By Murigi

The health benefits of vitamin B12

What is vitamin B12?

Vitamin B12 is a water soluble vitamin. For this reason, the body cannot store it for long. Another name for it is cobalamin. To avoid deficiency, it has to be replenished through certain foods that naturally contain it. Some processed foods are fortified with it and still you can get it through commercially prepared nutritional supplements. Under certain disease conditions, cobalamin can be prescribed as a medicine. This vitamin contains cobalt in its structure. There are different forms of B12.

Types of vitamin B12

  1. Methylcobalamin
This type is the most biologically active form in the body. It has many functions that include conversion of homocysteine to methionine. This helps in the control of homocysteine which is known to increase cardiovascular risk when out of control. It has neurological functions protection which includes the brain. It has the ability to cross the blood brain barrier (BBB) which is important for brain cells protection. It does this freely without the need for undergoing other body processes.
  1. Hydroxocobalamin
This is a synthetic form of vitamin B12.  This form cannot be used directly in the body until bacteria in the gut converts it into the biologically available form. The commercial preparations of the vitamin are synthesized by bacteria. This form is used mainly for medical treatment of diagnosed vitamin B12 deficiency.
  1. Adenosylcobalamin
This type is the most unstable of all the types of B12. It is not readily available although a few commercial supplement manufacturers have been able to stabilize it and avail it in form of tablets. It is needed for energy production in the citric cycle.
  1. Cyanocobalamin
This is a synthetic form of vitamin B12 and also the most readily available in supplements form. It is also the most stable outside the body. Health conscious people may want to know that it has a cyanide molecule in it. This molecule is apparently of no health concern but the body needs to process and remove it from the system.

Functions of vitamin B12 in the body

These include:
  • Making normal red blood cells
  • Maintenance of proper nerve functions
  • Supports the metabolism of folate
  • Supports the synthesis of citric acid
  • DNA synthesis
  • Methionine synthesis
  • Acts as a coenzyme in the proper working of DNA, RNA and metabolism of hormones, proteins and fats.
  • Hemoglobin synthesis

Symptoms of vitamin B12 deficiency

Some degree of vitamin B12 is fairly common. Common signs and symptoms include:
  • Non-specific symptoms such as generalized tiredness and weakness
  • Awareness of heartbeat
  • Respiratory problems including breathlessness
  • Lightheadedness
  • Skin pallor
  • Numbness and pins and needles sensation and other neurological disorders.
  • Difficulty in walking
  • Visual problems
  • The specific type it causes is called megaloblastic anemia
  • Sleepiness due to lack of energy
  • Forgetfulness
  • Smooth and red tongue
  • Emotional imbalance

Cause and risk factors of vitamin B12

The first thing to think about when a vitamin B12 deficiency is suspected or diagnosed is the type of diet a person has been taking. The diet may be deficient of the vitamin and correcting this may be the only measure needed to alleviate the problem. The state of the stomach, the pancreas and the small gut are however, the main determinants of vitamin B12 in the body. Other causes include:
  • Chronic inflammation of the stomach
  • Malabsorption disorders
  • Diabetics
  • The elderly
  • Lack of or inadequate intrinsic factor (IF)
  • Poor calcium metabolism
  • Pernicious anemia
  • pylori bacteria that can lead to peptic ulcerations
  • Alcoholics
  • Vegans
  • Pregnant mothers who don’t enhance their B12 intake during pregnancy
  • Genetic inherited disorders such as a type of IF deficiency

Sources of vitamin B12

Vitamin B12 is mainly sourced from animal products. This is a challenge for vegans. However, you can go round this issue by taking the following non-animal products.
  1. Fortified cereal products
  2. Yeast extract spreads
  3. Vitamin B12 nutritional supplements
  4. Fortified drinks
  5. Fortified soy

How vitamin B12 supports your health

  1. Cardiovascular health support
Vitamin B12 helps in the synthesis of methionine from homocysteine. This lowers the risk of high levels of homocysteine which has been associated with increased risk of heart disease. This works best where vitamins B6 and folate are also sufficient. The folate should not be inordinately high because it can mask the deficiency of B12 which can result in serious vitamin B12 complications such as permanent neurological disorders.
  1. Supports neurological and mental functions
Various studies have linked vitamin B12 deficiency with some mental functions decline. These include cognition. Studies have also found that the incidence of dementia and Alzheimer’s disease correlate with high homocysteine levels. Vitamin B12 may therefore reduce the incidence of these health conditions because it plays a role in reducing homocysteine levels by converting it to methionine. Adequate vitamin B12 availability to the body has also been associated with a lower incidence of neural-tube-defects (NTDs)
  1. Reduces the risk of cancer
Vitamin B12 helps in the metabolism of folate. Folate is important in the synthesis of DNA. When vitamin B12 is deficient in the body part of the available folate is rendered unavailable and the DNA synthesized under these conditions has an increased chance of damage. This can form the basis for cell malignant changes later. One study found that women with low vitamin B12 levels were almost twice as likely to develop breast cancer.

Other benefits of vitamin B12

Studies are ongoing and preliminary findings suggest that vitamin B12 has many more health benefits. A few of these include:
  • Physical endurance
  • Prevention of osteoporosis
  • Depression
  • May help in male fertility by improving sperm quality

Safety and precautions

Vitamin B12 is considered generally safe even in relatively high doses. Only small amounts are absorbed into the body when given orally. Some drugs can interfere with the vitamins uptake from the gut. This includes the prolonged use of omeprazole which is a proton-pump-inhibitor (PPI). Others are cimetidine (a Histamine2 – receptor antagonist), neomycin, chloramphenicol and the anti-diabetic metformin. Nitrous oxide inhibits vitamin B12 and should be used cautiously in the elderly and those at risk of deficiency.


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