Vitamin B12 is one of the most important vitamins because it is needed by every cell. Even minor shortages result in symptoms such as fatigue, impaired memory, breathlessness and headache. Greater deficiencies cause irreversible neurological damage, cardiovascular disease and depression. Under higher risk for deficiencies are vegan, vegetarian, people over 60 years of age and people with gastrointestinal and digestive problems.
In this article:
- What is vitamin B12?
- Natural sources of B12
- Deficiency and absorption of B12
- Measuring Vitamin B12 in blood
- Dietary supplements with B12
What is vitamin B12?
Vitamin B-12 is called Cobalamin and is a water soluble vitamin. Vitamin B12 is of utmost importance because it is needed for the metabolism of every cell in the body. It is a cofactor in the synthesis of DNA and the metabolism of fatty acids and amino acids.
It is especially important for the normal functioning of the nervous system due to its role in the synthesis of myelin (myelin is the insulating sheath of the nerves, similar to isolation of electrical conductors – for example, Multiple sclerosis is a disease that damages myelin sheath).
Of all B vitamins, B12 is the largest and structurally most complex. Its extraordinary significance is probably due to the fact that it contains a rare element of cobalt from which it also derives the name Cobalamin.
How Vitamin B12 is made nature?
The only organisms that can produce B12 are specific bacteria and archaea (bacteria-like organisms). They are located in the soil around the grass that are eaten by ruminants. When they enter their digestive tract, they proliferate and produce vitamin B12, which is then transported along the food chain.
Plants do not produce B12, so it is a much recommended supplement to the vegan diet!
What foods contain B12?
The most common sources of B12 are: meat, liver, milk and dairy, eggs and fish.
Vitamin B12 deficiency
Vitamin B12 deficiency can cause severe and irreversible damage, especially on the brain and nervous system.
Deficiencies are common among vegans, as well as vegetarians, as they do not consume it enough with food.
Among omnivores deficiencies are mostly due to absorption problems.
Vitamin B12 and absorption
Vitamin B 12 has slightly specific absorption. When it comes into the stomach it must first bind to the so-called intrinsic factor, which is excreted together with gastric acid. Only this connection prevents the digestive enzymes from breaking down and thereby destroying this vitamin when traveling through the intestines.
Vitamin B12 is absorbed at the end of the small intestine in the area called the ileum.
Because of such a complex absorption mechanism, disorders are frequent. A very common phenomenon of the modern world is gastric acid deficiency and with it comes intrinsic factor deficiency. Deficiencies are more common with higher stress and age.
The frequent use of gastric acid-reducing medicines (antacids, proton pump inhibitors) leads to reduced absorption of B12. These include medicines such as Prilosec, Protonix, Prevacid, Nexium and the like. Frequent use of baking soda can have the same effect.
Deficiency of vitamin B12 is also proven to be caused by the most common drug for type 2 diabetes, metformin. Metformin contains medicines such as: Aglurab, Glucophage and Siofor.
Patients with a gastric bypass are also at high risk.
Research has shown that approximately 80% of vegans and 39% of the general population have vitamin B12 deficiency. This means that if you are in a room with 9 other people, 4 of you have a vitamin B12 deficiency.
Signs of vitamin B12 deficiency
Even at very small deficiencies symptoms can present them selves, like:
- problems with walking and balance,
- impaired memory,
- short breath,
- inflamed, swollen tongue,
- tingling and needle pain in the extremities,
- lack of taste and
- pale skin.
Major deficiencies can cause mania and psychosis as B12 is involved in the production of many neurotransmitters.
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Deficiency also leads to reduced red blood cell and hemoglobin production, and thus to anemia, which is not necessarily associated with iron deficiency.
A deficiency can also lead to high homocysteine (an amino acid derived from methionine that in high quantities damages the blood vessels). What most do not know is that high homocysteine is a higher risk factor for cardiovascular disease than high cholesterol. Vitamin B12, together with B9, provides good methylation of homocysteine and reduces it in the body.
And with this we have only touched the many functions B12 plays in our bodies.
High doses of vitamin B12 have been found to be beneficial in the fight against hepatitis C virus.
Measuring vitamin B12
There are several different options for measuring vitamin B12 in the body. The most used is the direct B12 serum test, which is not the most accurate. Nevertheless, it may show a shortage of B-12 in the serum measured in peta moles per liter (pmol/L). Laboratory reference values are often between 130 and 650 pmol/L, but at the lower limit is where already severe neurological disorders occur, while the first symptoms may occur at values around 360 pmol/L.
If your serum values of B-12 are higher than 700 pmol/L without suplementation, this can be an indication of other illnesses or disorders (this of course isn’t the case if the values are high because of supplementation).
Since vitamin B12 in the serum is a direct measurement of this vitamin, it does not say anything about how the body uses it. A more accurate measurement of the biological activity of vitamin B12 in the body is therefore a marker called methyl malonic acid or MMA.
A little more rarely I used marker is holotranscobalamin, which is the most accurate of all, except if kidney disease is present.
Also, high homocistein can be sign of B12 deficiency.
B12 and folates
B9, folic acid or folate can mask vitamin B12 deficiency, so B12 is usually added to B9 supplementation. B9 masks the symptoms associated with anemia, which may arise due to B12 deficiency. Therefor, if you are taking B9 supplements, pay attention to your B12.
Dietary supplements with vitamin B12
There are 3 primary forms of B12 in dietary supplements:
Cyanocobalaminis the easiest to produce, the most stable and cheapest, and is therefore present in most food supplements, but unfortunately it is also the least beneficial. In this form, cobalamin is bound to a cyanide molecule, which you probably know as a poison. Cyanocobalamin does not occur naturally and occurs during purification of cobalamin via activated charcoal. Cobalamin strongly binds cyanide, in fact, so strongly that it is used by medicine as an antidote for acute cyanide poisoning.
This antidote is hydroxycobalamin. This is cobalamin bound to the hydroxyl group and is poorly stable. When it comes close to cyanide, it immediately binds it and replaces the hydroxyl group. Bacteria produce it directly, and in food supplements it is extremely rare due to complicated production and poor stability.
Methylcobalaminis the best form of vitamin B12 in nutritional supplements since it is relatively stable and directly metabolically active (cyanocobalamin active, since the body must first convert it into methyl cobalamin before it can be used).
If you want a quality product check the label and pick the one that has methylcobalamin in it and does not contain any cyanocobalamin.
Also the capsule in important. Hard tablets and some capsules are not always well dissolved in the stomach, which can limit the binding to the intrinsic factor and thus lead to poor absorption. Best are the forms of lozenges or spray. Both forms are partially absorbed in the mouth, and thus circumvent the absorption problems in the intestines.
Recommended dosage B12
The regulatory minimum doses range from 4 to 5 micrograms, but B12 is non-toxic also at extremely high doses. As a rule, 1000mcg is used as a common daily dose and in special cases it can go up to 10,000mcg daily.
Research has shown that 500mcg daily is usually enough to normalize B12 levels except in individuals with poor absorption and the elderly.
Tablets and capsules are better absorbed when taken with meals, but you can take lozenges or sprays also on an empty stomach.