Vitamin B12

Vitamin B12 or cobalamin is a vitamin that can only be produced by microorganisms. As vitamin B12 cannot be produced by plants, the question of the extent to which a purely plant-based diet provides an adequate supply of the vitamin is a recurring topic of discussion. There are four cobalamin compounds (vitamin B12 active compounds) that have a biological effect in humans and animals: Adenosyl-, aquo-, hydroxy- and methylcobalamin and the synthetic compound cyanacobalamin. With the exception of cyanacobalamin, these compounds are sensitive to light and heat. Oxygen significantly accelerates the inactivation of cobalamins. The cobalamin ingested with food is released from the food by hydrochloric acid and the enzyme protease in the stomach. Before the vitamin enters the bloodstream, it binds to certain proteins that serve as a "transport system" for the cobalamin into the bloodstream. It is transported to the organs via another protein bond.

It binds to the beta-globulin transcobalamin which is recognized as a receptor on the cell surface. Transcobalamin facilitates the absorption of the vitamin into the cells. The "recycling" of the vitamin plays a significant role in cobalamin metabolism. The cobalamin excreted via the bile can reattach to a "transport protein" in the small intestine, which enables it to be reabsorbed into the bloodstream. Vitamin B12 is mostly absorbed in the terminal ileum. A transport protein, the so-called intrinsic factor, is necessary for absorption. This factor is produced in the gastric mucosa and is reduced in so-called A-gastritis, so that a vitamin B12 deficiency can develop as a result. In the case of intestinal diseases (Crohn's disease) or after resection of the terminal ileum or stomach, vitamin B12 supplementation may be necessary.

What is Dibencozide?

Dibencozide is a form of vitamin B12 that is used as a medicine. Taken orally or placed sublingually under the tongue, Dibencozide is used to help the body process protein, increase muscle mass and strength, improve mental focus and treat depression, anxiety and panic attacks. In the 1990s, Dibencozide was marketed as a bodybuilding supplement with steroid-like effects, but almost completely disappeared from the market a few years later.

Task/function

B12 has two main functions in the body. It is needed in the bone marrow for the formation of red blood cells and in the nervous system. It acts as a co-enzyme in DNA synthesis and promotes protein synthesis and carbohydrate and fat metabolism.

Potential health benefits of vitamin B12

Vitamin B12 helps in the formation of red blood cells and can prevent anemia

Vitamin B12 plays a crucial role in the production of red blood cells in the body. Low vitamin B12 levels can lead to reduced red blood cell formation and prevent their proper development (1). Healthy red blood cells are small and round, whereas in the case of vitamin B12 deficiency they become larger and oval. Because of this irregular shape, these red blood cells are unable to move from the bone marrow into the bloodstream at a sufficient rate, resulting in megaloblastic anemia (1). When the body is anemic, it does not have sufficient amounts of red blood cells to carry oxygen to vital organs. This can cause symptoms such as fatigue and weakness.

Summary: Vitamin B12 is involved in the production of red blood cells and in the case of a deficiency, it can lead to a change in red blood cell production and megaloblastic anemia.

Vitamin B12 can prevent birth defects

Adequate vitamin B12 levels are crucial for a healthy pregnancy. Studies have shown that the brain and nervous system of the fetus need sufficient amounts of vitamin B12 from the mother in order to develop properly. A vitamin B12 deficiency in the early stages of pregnancy can increase the risk of birth defects in the nervous system. In addition, a vitamin B12 deficiency in the mother can contribute to premature births or miscarriages (2). One study found that women with vitamin B12 levels lower than 250 mg/dl were three times more likely to have birth defects than women with adequate vitamin B12 levels (3). In women with a vitamin B12 deficiency and levels below 150 mg/dl, the risk was even five times higher compared to women with levels above 400 mg/dl (3).

Summary: Adequate vitamin B12 levels are crucial for a healthy pregnancy as they can prevent birth defects in the brain and spinal cord.

Vitamin B12 can support bone health and prevent osteoporosis

Maintaining adequate vitamin B12 levels can support bone health. A study of more than 2,500 adult subjects showed that subjects who were vitamin B12 deficient also had lower than normal bone mineral density (4). Bones with reduced mineral density can become fragile and brittle over time, leading to an increased risk of osteoporosis. Other studies have also shown a link between low vitamin B12 levels and poor bone health and osteoporosis, particularly in women (5, 6, 7).

Summary: Vitamin B12 plays a role in bone health and low vitamin B12 levels are associated with an increased risk of osteoporosis.

Vitamin B12 could reduce the risk of macular degeneration

Macular degeneration is an eye disease that mainly affects central vision. Maintaining adequate vitamin B12 levels could help reduce the risk of age-related macular degeneration. Scientists believe that vitamin B12 supplementation can lower homocysteine levels - an amino acid found in the bloodstream. Elevated homocysteine levels are associated with an increased risk of age-related macular degeneration (8, 9).

A study of 5,000 female subjects aged 40 years or older concluded that vitamin B12 supplementation in combination with niacin and vitamin B6 could reduce the risk of macular degeneration (10). A group that received these supplements for a period of seven years had fewer cases of macular degeneration than the placebo group. The risk of developing any form of this disease was 34% lower and even 41% lower in certain types (11).

Summary: Maintaining adequate vitamin B12 levels lowers blood homocysteine levels, which may help prevent age-related macular degeneration.

Vitamin B12 can improve mood and relieve symptoms of depression

Vitamin B12 can improve mood. However, the effects of vitamin B12 are not yet fully understood. What is clear, however, is that this vitamin plays an important role in the synthesis and metabolism of serotonin - a chemical responsible for regulating mood. For this reason, a vitamin B12 deficiency could lead to a reduced release of serotonin, which can result in a depressed mood. Studies support the use of vitamin B12 supplements to alleviate symptoms of depression in people suffering from a vitamin B12 deficiency. One study conducted on individuals with depression and low vitamin B12 levels found that those who received both antidepressants and vitamin B12 were more likely to show improvements in symptoms of depression than those who received only antidepressants (11).

Another study found that vitamin B12 deficiency was associated with twice the risk of serious depression (12). In addition to this, high levels of vitamin B12 have been linked to better treatment outcomes and a higher likelihood of recovery from major depression (13). However, while vitamin B12 supplements may help alleviate symptoms of depression in people suffering from vitamin B12 deficiency, the research available to date does not suggest that these supplements have the same effect in people with normal vitamin B12 levels.

Summary: Vitamin B12 is needed for the production of serotonin - a chemical responsible for regulating mood - and vitamin B12 supplements may help improve mood in people who are vitamin B12 deficient.

Vitamin B12 may have a positive effect on the brain by preventing neuron loss

Vitamin B12 deficiency is associated with memory loss, particularly in older adults. Vitamin B12 may play a role in preventing brain atrophy, which is a loss of neurons in the brain often associated with memory decline and dementia. One study of people with early-stage dementia showed that a combination of vitamin B12 and omega-3 fatty acid supplements slowed mental decline (14). Another study found that even vitamin B12 levels at the lower end of the normal range can contribute to poor memory performance. As a result, vitamin B12 supplementation may improve memory even in the absence of a clinically diagnosed deficit (15).

Summary: Vitamin B12 may help prevent brain atrophy and memory decline.

Vitamin B12 could help in the treatment of Alzheimer's disease

Vitamin B12 may play a role in preventing Alzheimer's disease in older people (16). A meta-analysis of 68 studies found that Alzheimer's patients had significantly lower vitamin B12 levels. In addition, elevated homocysteine levels were identified as a risk factor for Alzheimer's disease. According to one study, taking vitamins B12, B6 and folic acid for two years may slow brain atrophy in areas associated with Alzheimer's disease and declining cognitive function in some patients (17).

Summary: Vitamin B12 may counteract the development of Alzheimer's disease.

Vitamin B12 can increase energy

Vitamin B12 supplements have long been touted as the product of choice when it comes to an energy boost. All B vitamins play an important role in the body's energy production, although they do not necessarily provide energy themselves (18). There is currently no scientific evidence to suggest that vitamin B12 supplements can increase energy in people who have adequate levels of this vitamin (19). However, if there is a significant vitamin B12 deficiency, then taking a supplement or increasing dietary intake may significantly increase energy levels (20). In fact, fatigue and lack of energy are among the first signals of vitamin B12 deficiency.

Summary: Vitamin B12 is involved in energy production in the body. In the case of a deficiency, taking vitamin B12 can increase energy levels.

Vitamin B12 could improve heart health by reducing homocysteine levels

High blood levels of the amino acid homocysteine are associated with an increased risk of heart disease. Homocysteine levels may be elevated in people who have a significant vitamin B12 deficiency. Studies have shown that vitamin B12 helps to lower homocysteine levels, which could reduce the risk of heart disease (21, 22, 23). However, there are still no scientific studies confirming that vitamin B12 supplements are effective in this regard (24). For this reason, further research is needed to better understand the relationship between vitamin B12 and heart health.

Summary: Vitamin B12 can lower blood levels of homocysteine - an amino acid associated with an increased risk of heart disease. However, so far there is no research showing that vitamin B12 can reduce the risk of heart disease.

Vitamin B12 supports healthy hair, skin and nails

When you consider the important role of vitamin B12 in cell production, it quickly becomes clear that adequate levels of this vitamin are needed to promote healthy hair, skin and nails. In fact, low vitamin B12 levels can cause various dermatological symptoms including hyperpigmentation, nail discoloration, hair changes, vitiligo (a patchy loss of skin color) and cracked, inflamed corners of the mouth (25, 26). Vitamin B12 supplementation has been shown to reduce dermatological symptoms in people suffering from vitamin B12 deficiency (27, 28). However, if you are well nourished and not deficient or low in vitamin B12, it is unlikely that vitamin B12 will improve the health of your skin, hair and nails (29).

Summary: Healthy vitamin B12 levels are important for skin, hair and nail health. However, a supplement will not improve these if adequate vitamin B12 levels are already present.

Vitamin B12 may be helpful for nerve pain and nerve damage.

According to a clinical study, treatment with vitamin B12 reduced pain symptoms in nerve conditions such as neuralgia, diabetic neuropathy and lower back pain (30, 31, 32). Injected methylcobalamin - a form of vitamin B12 - reduced clinical symptoms in the legs such as paresthesia (an abnormal tingling sensation), burning pain and spontaneous pain in some patients with diabetic neuropathy (33). A meta-analysis of 7 clinical trials confirmed the moderate benefits of vitamin B12 on some symptoms of diabetic neuropathy including pain (34). In one study, vitamin B12 significantly improved symptoms such as pain and tingling in patients with neck pain (35). Vitamin B12 also appears to be safe and effective when used for nerve pain due to herpes simplex infection, according to clinical trials involving 178 subjects (36, 37). In animal models, vitamin B12 improved different types of neuropathic pain, increased axon regeneration, and promoted neuronal repair (38, 39, 40, 41, 42).

Summary: Vitamin B12 can alleviate various forms of nerve pain and other symptoms of nerve disorders.

Vitamin B12 can counteract disorders of the sleep-wake rhythm

In a study of 126 patients, the majority of subjects with sleep disorders due to primary disturbances of the sleep-wake rhythm responded well to treatment with vitamin B12 and bright light. However, people with secondary sleep disorders due to primary disorders of the sleep-wake rhythm did not respond as well to treatment (43). In another study of 106 subjects with various sleep disorders due to primary sleep-wake rhythm disturbances, the results were variable, but most groups experienced mild to moderate improvements (44). On the other hand, high-dose methylcobalamin had no positive effects in a study of 50 patients with delayed sleep phase syndrome (45). Further studies are needed to clarify the contradictory effects of vitamin B12 supplementation on sleep disorders.

Summary: Vitamin B12 could provide relief for certain forms of sleep disorders.

Occurrence

Vitamin B12 is produced exclusively by microorganisms. Animals and plants are not able to do this. Animals, which also need vitamin B12, cover their requirements by eating "unclean" food containing such microorganisms. However, it is assumed that herbivores in particular cover the majority of their requirements through a symbiosis with these microorganisms in their intestines. These microorganisms are also found in the intestines of humans, where they produce vitamin B12. It is assumed that humans also cover a large part of their requirements in this way, because vitamin B12 only needs to be supplied in extremely small doses, in contrast to other vitamins, which are sometimes required by the gram.

This requires intact intestinal flora and early colonization of the microorganisms in the small intestine. This is because vitamin B12 produced in the large intestine is usually excreted unabsorbed. Vitamin B12 is stored very well in the liver and is usually found almost everywhere in food of animal origin. It used to be thought that the vitamin B12 requirements of vegetarian/vegan diets could be met by lactic acid fermented foods (sauerkraut, beet, lupin, algae). It is now known that these are primarily inactive vitamin B12 analogs.

Symptoms of deficiency

A vitamin B12 deficiency can lead to pernicious anemia (perniciousiosa), a disease of the blood count and to funicular myelosis. The causes of this deficiency can be insufficient intake through food, as has been observed in very strict vegan diets, or insufficient absorption. If there is insufficient absorption in the gastrointestinal tract, the organism lacks the intrinsic factor (a glycoprotein that is produced by the parietal cells of the stomach and in the duodenum and is essential for vitamin B12 absorption) in the gastric juice. The intrinsic factor binds cobalamin in a complex that protects it from digestive enzymes and thus enables it to be transported into the intestinal cells, from where vitamin B12 reaches the outer tissues by binding to other proteins (transcobalamins).

Which groups of people are at increased risk of vitamin B12 deficiency?

About 6% of all people in industrialized countries aged 60 years or older are vitamin B12 deficient, while about 20% are at the borderline of deficiency (46).

People at increased risk of vitamin B12 deficiency include (47):

• Older adults
• People with digestive tract disorders such as Crohn's disease or celiac disease
• People who have undergone gastrointestinal surgery such as bariatric surgery or partial bowel resection
• People who follow a strict vegan diet
• People who take metformin to control blood sugar levels
• People who take proton pump inhibitors to treat chronic heartburn or stomach acidity

In many older people, the secretion of stomach acid is reduced, which results in reduced absorption of vitamin B12. If the absorption of vitamin B12 via the digestive tract is impaired, vitamin B12 injections by a doctor may be an option.

Overdose

No toxic effects have been demonstrated even after ingestion of 10,000 times the dose. As vitamin B12 is water-soluble, excess amounts are excreted in the urine. No overdoses have been reported to date and even allergies to vitamin B12 are extremely rare.

Precautions and warnings

Pregnancy and lactation: Not enough is known about the use of vitamin B 12 during pregnancy and lactation. For this reason, pregnant and breastfeeding women should avoid vitamin B12.

Diseases of the digestive tra ct: Some diseases of the digestive tract, as well as surgical removal of part of the intestine, can reduce the amount of vitamin B12, including vitamin B12, that the body absorbs through the intestine.

Interactions

Care should be taken when using vitamin B12 in combination with the following medications:

Chloramphenicol

Vitamin B12 is a form of vitamin B12. Vitamin B12 is important for the production of new blood cells. Chloramphenicol could reduce the number of new blood cells. Taking chloramphenicol over a long period of time could reduce the effects of vitamin B12 on the production of new blood cells. However, as most people only take chloramphenicol for short periods of time, this interaction is not usually a major problem.

Requirements

The minimum daily requirement is much lower compared to most other vitamins, only about 3 micrograms. A vitamin B12 deficiency develops very slowly, usually only after two to three years if the intake is stopped completely, as the body can store the vitamin in the liver for a longer period of time.

Requirements in sport

Vitamin B12 enjoys a good reputation among athletes. Even when the vitamin is administered without any deficiency, they report an increased sense of well-being and increased appetite. Some swear by stimulatory and anabolic effects. Many bodybuilders take doses of up to 1500mcg a day.

References

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