- What are the benefits of vitamin B12?
- What are the forms of vitamin B12?
- What are the signs of a vitamin B12 deficiency?
- What are our vitamin B12 needs?
- In which foods do we find the most vitamin B12?
- Who needs vitamin B12 supplementation?
- Do vegetarians and vegans have vitamin B12 deficiencies?
- Is it good to take vitamin B12?
- Is vitamin B12 available in pharmacies?
- What dosage? What to do in case of overdose?
What are the benefits of vitamin B12?
There vitamin B12 (also called cobalamin) plays an important role in the energy production by its contribution to the metabolism of proteins, carbohydrates and lipids (like most B vitamins). It participates, with vitamin B9 and iron, in the production of red blood cells. Still with vitamin B9, it helps reduce cardiovascular risks by limiting homocysteine (an amino acid) which, in the blood, promotes the clogging of the arteries.
Through DNA synthesis and cell division, vitamin B12 contributes greatly to the formation and maintenance of tissues and cells.
Finally, vitamin b12 also plays an essential role in thebalance and protection of the nervous system by its maintenance of the myelin sheath, coating the neurons.
What are the forms of vitamin B12?
Vitamin B12 is naturally present in three forms in our body:
- There methylcobalamin ;
- I’adenosylcobalamin ;
- I’hydroxocobalamin.
In meat, vitamin B12 is mainly found in the form of adenosylcobalamin, up to 68%. In eggs and milk, it is mainly present in the form of methylcobalamin.
What are the signs of a vitamin B12 deficiency?
Many symptoms, both physical and emotional, can appear over long periods after a vitamin B12 deficiency. As they are not unequivocal, they are often difficult to recognize, and over time, can worsen. This difficulty in diagnosis is explained by the wide field of application of vitamin B12 in our body. Its various manifestations on the surface then turn out to be particularly complex to decipher, because many other elements may be involved in the appearance of signs of deficiency. However, the most common symptoms of vitamin b12 deficiency can be divided into four categories:
- Nerve disorders (numbness, joint pain, coordination problems);
- Digestive problems (canker sores, intestinal inflammation, diarrhea, constipation);
- Anemia (fatigue, hair loss, lack of concentration, immune weakness);
- Hormonal and neuronal problems (depression, psychological disorders, psychosis).
What are our vitamin B12 needs?
According to the age categories, the vitamin B12 needs are :
- Infants under 6 months: 0.4 µg per day;
- Infants 6 months and older: 1.5 µg daily;
- Children 1 to 3 years old: 1.5 µg per day;
- Children 4 to 10 years old: 1.5 mcg per day;
- Adolescents 11 to 17 years old: 2.5 mcg per day;
- Men and women 18 years and older: 4 mcg per day;
- Pregnant women: 4.5 µg per day;
- Nursing women: 5 µg per day.
In which foods do we find the most vitamin B12?
Herbivores and mammals have a digestive system whose bacteria are able to synthesize vitamin B12. The human gut microbiota can produce this vitamin, but only in our colon, in the terminal section of the small intestine. The vitamin B12 secreted by the body therefore does not reach the stomach and the liver, and is mainly evacuated in the stool. Consequence: it is through a diet rich in B12 that this contribution must be made.
If foods of plant origin do not contain vitamin B12 that can be assimilated by humans, the same is not true for those of the animal kingdom. Products of animal origin are indeed the exclusive natural food sources for this vitamin.
Here is the list of meats and fish containing a more or less important rate of vitamin B12 (micrograms per serving of 100 grams):
- Beef liver = 91 µg;
- Calf liver = 60 µg;
- Pork liver = 39 µg;
- Beef kidney = 33 µg;
- Cooked periwinkle and raw oyster = 24 to 39.5 µg;
- Canned cod liver = 15.7 µg;
- Canned sardine = 14 µg;
- Mackerel = 9 µg;
- Herring = 8.5 µg;
- Cooked shrimp = 5 µg;
- Salmon = 4.7 µg;
- Canned tuna = 4.3 µg.
The list of vegetarian foods with the microgram content per 100 gram serving:
- Swiss cheese = 3.1 µg;
- Camembert = 2.6 µg;
- Edam = 1.9 µg;
- Hard-boiled egg = 1.1 µg;
- Cottage cheese = 0.8 µg;
- Dairy products = 0.5 µg.
Who needs vitamin B12 supplementation?
Normally, theassimilation vitamin B12 is easily made in the last portion of the small intestine thanks to the intrinsic factor, a molecule secreted in the stomach. For absorption to take place, the degree of acidity must be normal in the stomach.
The elderly have the particularity of produce less stomach acid, an important element in the release of vitamin B12 from food for incorporation into the blood. This age category also has vitamin B12 deficiencies due to changes in eating habits, chronic illnesses and taking medication.
Pregnant and breastfeeding women see their vitamin B12 needs increase, including for their babies. The good health of the mother and the harmonious development of the fetus are linked. A severe deficiency during pregnancy can lead to miscarriage or neurological damage to the child.
People suffering from Crohn’s disease, Biermer’s disease or repeated gastritis need to supplement with vitamin B12. Indeed, it is much less well assimilated in these cases of chronic gastrointestinal disease. Long-term treatment with metformin for type 2 diabetes mellitus also interferes with the absorption of vitamin B12. Similarly, drugs to combat stomach acidity can lead to a similar disturbance. Supplementation is also necessary after heavy surgical gastric removal (stomach or intestine).
Do vegetarians and vegans have vitamin B12 deficiencies?
People following a vegan dietor having excluded foods of animal origin where vitamin B12 is found, are exposed to the risk of deficiency and must turn to vitamin b12 supplementation.
On the other hand, the diet of vegetarians is less restrictive since it allows the consumption of milk, cheese and eggs. Nevertheless, the vitamin B12 level of this diet being lower, it is advisable for their followers to supplement themselves with food supplements.
Is it good to take vitamin B12?
There have been no reported cases of high-dose vitamin B12 excess resulting in death. Excess vitamin B12 seems almost impossible, because the body can simply get rid of this excess of a water-soluble vitamin by the simple action of the kidneys then by evacuation through the urine.
Is vitamin B12 available in pharmacies?
Can you get vitamin B12 in pharmacies without a prescription? This dietary supplement is actually available in pharmacies in the form of tablets, capsules, ampoules or drinkable drops. Nevertheless, even if vitamin B12 is not toxic, self-medication has its limits and it is advised to consult a doctor before using dietary supplements. Especially since if you have a deficiency, for example due to a disease that disrupts its absorption by your body, this health professional will prescribe you vitamin B12.
Its prescription, based precisely on your case and your characteristics (symptoms, age), is then completely adapted to your needs. It is regularly prescribed intramuscularly, especially for subjects with gastric pathology, preventing its absorption. By this prescription, this drug is then covered by Social Security.
What dosage? What to do in case of overdose?
If the risk of overdose dangerous to health is non-existent (as mentioned above), it is however necessary to follow the prescriptions of your doctor or the recommendations of the leaflet of the food supplement. There is no point in wasting doses of vitamin B12 to no avail. It is better to carry out a blood test to better know the rate you may need daily if there is a deficiency.
Source :
Read also:
- Vitamin C: benefits, where to find it, signs of a deficiency
- Vitamin D3: benefits, dosage, side effects
- Vitamin B8 (H): benefits, sources and needs