Vitamin B12 is a water-soluble vitamin that is essential for the construction and regeneration of many cells.
The daily requirement of vitamin B12 to an adulo healthy is 2.4 micrograms.
In part, its functions are closely related to folic acid, another water-soluble vitamin.
Both are involved in the synthesis of DNA and RNA, and in the conversion of homocysteine to methionine (an essential amino acid).
Excess homocysteine may facilitate the formation of blood clots and damage to the blood vessels, so it will grow in the blood is considered today by many doctors as a cardiovascular risk factor.
Vitamin B12, regardless of folic acid, is also involved in the synthesis of the myelin sheath that protects nerves.
What are the food sources of vitamin B12?
Vitamin B12 is synthesized by bacteria, fungi and algae. The nature is found in many chemical forms, but not all are metabolically active in the human body.
Currently we know that dietary sources of active vitamin in our diet are meat, fish, eggs and dairy products in smaller quantity (mostly aged cheeses), because the animals are able to amass the active form in their tissues.
For years in the scientific community there has always been doubt that algae can become or not reliable sources of vitamin B12 in vegetarian diets.
In a recent study published in 2014 on Nutrients was detected in the nori also the presence of active vitamin B12.
Given the existence of many inactive analogues, could hamper the absorption of the active form. For these reasons, in the absence of further research in humans, it is not recommended to use algae as the only reliable source of vitamin B12, especially in vegan diets.
Who is at higher risk of vitamin B12 deficiency?
Vitamin B12 to be absorbed by our intestine, it needs to be separated from protein which is bound by the action of hydrochloric acid and pepsin produced by the stomach, only to be tied to a glycoprotein called intrinsic factor, which is also produced by the stomach.
The absorption will occur at the end of the small intestine, but in order to be recognized by intestinal receptors, this vitamin must be necessarily linked to intrinsic factor.
Obviously that all those people who suffer from stomach disorders such as atrophic gastritis (frequent in the elderly population) are at risk for deficiency cause absorption.
In addition to gastritis, other damage to the stomach or small intestine can cause vitamin B12 deficiency.
Even people who take antacids and gastroprotective chronically should discuss with your doctor the condition of vitamin B12 in the blood.
Another category of people at risk of vitamin B12 deficiency include vegans and sometimes to a lesser extent even vegetarians if not taking adequate servings of eggs and dairy products or foods with added.
In a meta-analysis published in the scientific journal 2014 Nutrients, scholars showed a prevalence of 50-70% of values of vitamin B-12 are not ideal in vegetarian and vegan living in different European countries and outside Europe including Italy.
It is necessary to specify that, like folic acid, vitamin B12 is continuously secreted and reabsorbed with bile.
Just because a good part of this vitamin is constantly being reabsorbed, it is rare that healthy people develop this vitamin deficiency, even when the intake from the diet is minimal.
Most forms of vitamin B12 deficiency in fact reflect an absorption problem due to lack of intrinsic factor.
Vitamin B12 deficiency can also be observed in people who follow a vegan diet for many years (even 10-15 years), this is because at some point the body ends its stock and bile resorption is no longer able to meet the needs.
What are the symptoms of vitamin B12 deficiency?
Since this vitamin is involved in the synthesis of DNA, a deficiency leads to initially load alteration those organs or tissues that are more frequently meeting in cell renewal.
Among the diseases linked to vitamin B12 deficiency are megaloblastic anemia, where red blood cells are few and large and gods are not able to bind oxygen effectively and transport it to the cells.
The main symptoms are similar to iron deficiency anemia: headaches, chronic fatigue, shortness of breath, difficulty concentrating, etc.
Moreover, given that vitamin B12 is essential for the protection and optimal growth of nerves, even marginal deficiency of vitamin B12 can lead to low scores in tests that measure intelligence, spatial skills and short-term memory.
Neurological symptoms of vitamin B12 deficiency include advanced progressive paralysis that usually starts from the extremities of the body. If the deficiency is caught in time and correctly, you can prevent permanent damage to the nervous system.
One of the critical aspects of the diets completely without adequate integration, is that it is very rich diet of folic acid and vitamin B12 inactive analogues present in the plant Kingdom.
Folic acid is able to correct the symptoms of megaloblastic anemia but no nerve damage.
But so be careful to take folic acid supplements, especially women pregnant vegan or vegetarian, without first assessing the status of vitamin B12.
How do I know if I am deficient in vitamin B12?
It is necessary to assess, through blood tests prescribed by a doctor, the hematocrit, the level of folic acid, vitamin B12 and homocysteine.
These values appropriately integrated your doctor will need to assess vitamin B12 status, while the measurement of vitamin B12 alone is not enough to make an accurate diagnosis, because there may be inactive analogues, frequent in the plant Kingdom.
What are the remedies to vitamin B12 deficiency?
The solution is to integrate this vitamin in their diet.
There are 2 options:
Adequate intake portions during the day of fortified foods in vitamin B12.
Currently in Italy you can find milks and vegetable yogurt, breakfast cereals, fortified energy bars in vitamin B12. It is necessary that the exact amount of vitamin B12 present in the product is shown on the label.
Taking a supplement in pills or drops (suitable for children) or via intramuscular injection.
For people with impaired absorption, sub-lingual integration or intramuscularly are ideal because they bypass the gastrointestinal absorption. Consider more adequate integration with your doctor.
Folic acid is a vitamin B12 deficiency?
Absolutely not.
As stated before, the integration of folic acid could mask a vitamin B12 deficiency and not allow a prompt diagnosis to prevent neurological impairments associated with deficiency of this vitamin.
A dietitian or a nutritionist can help you if you decide to follow a vegetarian or vegan diet and can advise what form of integration, according to its weekly supply and individual preferences.