The benefits of vitamins B1, B2, B6, and B12 according to research

If there is one thing that all B vitamins have in common, it is this: they are water-soluble and act as coenzymes.

Water-soluble means that these vitamins are not stored in the body, so they must be taken daily for the best effect. The only exception is vitamin B12, the excess of which is stored in the liver.

Coenzyme means that these vitamins support the functioning of enzymes. Enzymes are proteins that speed up chemical reactions in the body but cannot work on their own. They need coenzymes, like B vitamins, to act as a switch that activates them.

Vitamin B1, popularly known as Thiamine, helps the body convert food into energy by turning it into adenosine triphosphate (ATP), which is the energy used by cells. It is also important for the proper functioning of nerve cells.

Low thiamine levels can lead to impaired mitochondrial activity, damaged oxidative metabolism, and reduced energy production. This can cause cell death, especially of neurons, which are more vulnerable due to their high energy needs. Thiamine can also act as an antioxidant, scavenging free radicals.

Thiamine is essential for the production of acetylcholine and myelin, as well as for maintaining levels of glutamate, aspartate, and gamma-aminobutyric acid (GABA). A thiamine deficiency can lead to neuronal excitation and delirium due to low levels of acetylcholine, reduced levels of GABA, and an increase in its precursor, glutamate.

Thiamine has no upper toxicity limit, which means you do not have to worry about excessive intake. On the other hand, thiamine deficiency can lead to health problems such as swelling of the lower limbs, loss of muscle coordination, weight loss, reduced immunity, and confusion.

Vitamin B2, also known as Riboflavin, is a key component of two coenzymes necessary for energy production, cellular function, and metabolism. It also supports the activity of other B vitamins.

Active forms of riboflavin are essential for the synthesis of niacin, folic acid, and vitamin B6. It is also necessary for the metabolism of carbohydrates, proteins, and fats into glucose. Its antioxidant effect is vital for cellular respiration and immune system function.

Anticonvulsants, anticholinergics, and phenothiazines reduce the absorption of riboflavin. Deficiency can be observed in liver diseases, alcoholism, and hemodialysis.

Riboflavin has no upper toxicity limit. Riboflavin is found in many animal products, such as meat and dairy products. People who do not consume animal products or consume them in small quantities may be at a higher risk of deficiency, but this is extremely rare. This is due, at least in part, to the fact that some foods that do not naturally contain riboflavin are commonly fortified with it.

Vitamin B6, also known as pyridoxine, is a water-soluble vitamin that occurs naturally in many foods, as well as in fortified foods and dietary supplements. The active coenzyme form of vitamin B6 is pyridoxal 5'-phosphate (PLP), which is the most commonly used measure for determining B6 levels in the blood.

PLP acts as a coenzyme and assists over 100 enzymes in performing various functions, including the breakdown of proteins, carbohydrates, and fats; maintaining normal homocysteine levels (high levels of which can lead to heart problems); and supporting immune function and brain health.

On one hand, vitamin B6 may reduce high levels of homocysteine in the blood, which are linked to the risk of Alzheimer's disease. One study of 156 adults with high homocysteine levels and mild cognitive impairment showed that high doses of vitamins B6, B12, and folate (B9) reduced homocysteine and decreased atrophy in some areas of the brain vulnerable to Alzheimer's disease.

Further studies are needed to examine the effect of vitamin B6 alone on homocysteine levels and brain function to better understand its role in improving brain health.

Vitamin B12, also known as cobalamin, is found in animal foods and can be added to fortified foods or dietary supplements. This vitamin is necessary for the formation of red blood cells and DNA, as well as for the proper functioning and development of brain and nerve cells.

Vitamin B12 deficiency is linked to memory loss, especially in older people.

A study in people with early-stage dementia shows that vitamin B12 may help slow cognitive decline in some people, but only in those who have higher levels of omega-3 fatty acids. In people with lower levels of omega-3 fatty acids, no slowing of mental decline was observed.

Another study found that even vitamin B12 levels at the low end of the normal range can contribute to poor memory performance.

Vitamin B12 plays a vital role in the production of red blood cells in the body.

Low levels of vitamin B12 lead to a reduction in the formation of red blood cells and interfere with their proper development. Healthy red blood cells are small and round, while in a vitamin B12 deficiency, they become larger and usually oval.

Cobalamin – Vitamin B12, is bound to the proteins in the foods we eat. In the stomach, hydrochloric acid and enzymes release vitamin B12 from these proteins. Vitamin B12 then binds to a protein called intrinsic factor, which allows it to be absorbed in the small intestine.