Vitamin B12 is perhaps the most underrated vitamin . Some time ago, the German Nutrition Society (DGE), together with the specialist societies in Switzerland and Austria, raised the reference value for vitamin B12 (display) from three to four micrograms per day.

“This is an estimated value based on studies in which several parameters were measured in the blood,” reports Silke Restemeyer, qualified ecotrophologist and consultant at the DGE.

According to the data of the National Consumption Study (NVS II) , most adult men and women consume sufficient vitamin B12, but risk groups are often undersupplied.

Who is at risk for vitamin B12 deficiency

These are people aged 65 and over because the absorption and utilization of vitamin B12 from food no longer works so well for them. They only produce the so-called intrinsic factor in smaller quantities. This is an enzyme that acts as a transporter and brings the vitamin to the intestinal cells for absorption . Only a fraction of the vitamin can therefore develop its effect.

Other risk groups:

• vegan
• Vegetarians, especially during pregnancy and breastfeeding
• People in whom the absorption of vitamin B12 in the stomach and intestines is disturbed, for example with chronic inflammation in this area such as gastritis , Crohn’s disease , ulcerative colitis
• Anyone who takes certain medications on a long-term basis, such as proton pump inhibitors (against too much stomach acid), metformin (diabetes medication)
• Who is constantly under stress: Because the vitamin is involved in the formation of stress hormones, among other things. That is why the vitamin B12 stores are emptied with constant psychological overload.
• Who drinks a lot of alcohol : Many people who consume a lot of alcohol have a vitamin B12 deficiency.

Vitamin B12 essential for low homocysteine

Vitamin B12 is actually a collective term for various cobalamins, such as hydroxy and adenosylcobalamin in fish and meat, and methylcobalamin in milk. As a coenzyme, vitamin B12 is involved in various metabolic processes in the body. The problem: the body cannot produce it itself and it is essential for life. The main roles of vitamin B12:

• It is involved in cell renewal and blood formation.
• It stabilizes the DNA.
• It protects nerves and the brain.
• It supports the protein and fat metabolism.
• Vitamin B12 converts the unfavorable homocysteine ​​into the less harmful methionine. Homocysteine ​​is an amino acid that damages blood vessels, promotes arteriosclerosis and is associated with heart attacks and strokes.

The role of vitamin B12 as lowering homocysteine ​​levels is particularly interesting. Various studies have shown that an elevated homocysteine ​​level significantly increases the risk of heart attack and stroke. Low homocysteine ​​levels, as made possible by vitamin B12, are therefore beneficial.

Vitamin B12 Deficiency – The Signs

According to its diverse functions, the signs of a vitamin B12 deficiency are also very different and range from all symptoms of anemia (paleness, tiredness) to concentration problems, dizziness, muscle weakness and neurological disorders and nerve damage such as neuropathy with sensory disorders in the legs. This nerve damage can be irreversible if the vitamin deficiency persists for a long time.

The main topic of discussion is how a vitamin B12 deficiency is related to an increased risk of dementia such as Alzheimer’s . “Studies show that cognitive performance is often reduced when there is a vitamin B12 deficiency, but the data situation is contradictory when it comes to preventing these changes with vitamin B12 supplements,” states nutrition expert Restemeyer.

Have vitamin B12 status checked professionally

Anyone who notices one of the symptoms mentioned and / or belongs to the risk groups should ideally have a corresponding blood test carried out by a doctor. “It is important to measure at least two biomarkers, for example total vitamin B12 and holo-TC (holo-transcobalamin) in the serum or plasma, as well as a meaningful functional parameter such as methylmalonic acid (MMA) or homocysteine ​​in the serum,” advises Silke Restemeyer. The blood test costs from 16 euros.

How to eat enough vitamin B12 every day

If the deficiency is not pronounced, it is usually sufficient to modify your nutritional plan a little and focus on the B vitamin. The following foods are rich in vitamin B12: meat, fish, dairy products, eggs.

The DGE gives an example of a daily schedule with which the reference value of four micrograms can be achieved:

• 150 ml milk with 1.5% fat i. Tr. = 0.6 micrograms of vitamin B12
• 1 small cup of yogurt with 1.5% fat i. Tr. = 0.6 micrograms of vitamin B12
• 1 boiled egg = 1.14 micrograms of vitamin B12
• 60 gr Camembert with 30% fat i. Tr. = 1.86 micrograms of vitamin B12

Total = 4.2 micrograms of vitamin B12

or

• 100 grams of cooked, lean beef = 4.5 micrograms of vitamin B12
• 60 gr cream cheese with 50% fat i. Tr. = 0.3 micrograms of vitamin B12
• 30 gr Gouda with 30% fat i. Tr. = 0.66 micrograms of vitamin B12

Total = 5.46 micrograms of vitamin B12

Incidentally, vitamin B12 is quite heat-stable, so it is hardly lost when heating, frying or cooking.

Vegetarians and vegans shouldn’t rely on sauerkraut and algae

Those who consciously avoid meat, or even eggs and dairy products, are at great risk of developing a vitamin B12 deficiency. Many vegans and vegetarians then trust that some plant-based foods also contain the nerve vitamin, such as fermented vegetables or certain algae. Because all other vitamins, including some B vitamins, are also contained in plant foods.

“However, this does not apply to vitamin B12, it is the only vitamin that occurs in significant amounts (almost exclusively) in meat, fish, seafood, eggs and dairy products – but not in plant-based products,” explains the nutritionist.

Sauerkraut (through fermentation with the help of bacteria) and algae actually provide vitamin B12, but either in such small quantities that they are hardly a source – or they are so-called vitamin B12 analogues. These forms do not work like the vitamin, but block the B12 transport in the body and thus even trigger the opposite: The body cannot utilize the little effective vitamin B12 that may be present.

The body often uses vitamin B12 from tablets better

“Vegans should definitely and permanently take a vitamin B12 preparation and have the supply checked regularly by a doctor,” advises the nutritionist. Vegetarians who have an increased need for nutrients, for example during pregnancy and breastfeeding, should also ensure that they have a sufficient supply of vitamin B12.

If a vitamin B12 deficiency has been proven, it should be compensated for with appropriate dietary supplements. This can be done orally as tablets and capsules. Tolerance and bioavailability are good. Vitamin B12 and “cyanocobalamin as a crystalline substance, as is often found in food supplements, is even better utilized by patients with gastritis than vitamin B12 from food,” reports the expert.

Overdosing with the commercially available vitamin B12 food supplements is hardly possible if handled sensibly. Silke Restemeyer: “In a study with dialysis patients, no undesirable effects were recorded after years of intake of 2.5 milligrams after each dialysis (i.e. a multiple of the estimated value of 4 or 5 micrograms).” Still important: with long-term intake of vitamin B12 -Preparations, the vitamin B12 status should be checked from time to time.

Vitamin B12 as an injection

However, sometimes this active supplementation is not enough. This can be the case if there are one or more factors such as: 

• The deficiency is very pronounced.
• Absorption disorders – for example due to old age or chronic inflammation of the digestive tract
• Drugs that prevent the vitamin from being absorbed but cannot be suspended or replaced

Then the doctor recommends taking a vitamin B12 injection treatment. The vitamin is given muscularly at intervals of a few days or a week. Depending on the product, an injection costs around five to ten euros.

Vitamin B12 has as yet unknown potential

So far, vitamin B12 has been an underestimated vitamin. How important and diversified its effect is is only gradually being revealed by studies . A clear, preventive effect of vitamin B12 in combination with B6 and folic acid against strokes has been proven.

The vitamin could also play a role in cancer. However, there are still few and sometimes contradicting studies. But this is where its ability to stabilize DNA and thus prevent mutations could come into play.