Vitamin B12

Some foods help our bodies work well.

This special helper is found in meat and fish. It is also in eggs and milk.

Plants do not make this helper themselves. Tiny living things like bacteria make it. It helps our blood stay healthy. It also helps our brain and nerves. Without it, we might feel very tired.

You can find it in some breakfast cereals too. It helps you grow strong and stay well.

Vitamin B12 is a very special helper for our bodies. It is also called cobalamin. It is the most complex vitamin of all. Tiny living things like bacteria and archaea make it.

Animals need it to stay healthy. Plants do not need it because they have other ways to work.

This vitamin helps our bodies in many ways. It helps make DNA, which is the code for our cells. It also helps make red blood cells in our bone marrow.

B12 helps our nervous system work well. It supports myelin, which is a part of our nerves.

You can find B12 in many foods. Meat, fish, and shellfish have it. Eggs and dairy products like milk also have it. Some people add it to breakfast cereals.

Some people might not get enough B12. Vegans and vegetarians are at higher risk. This is because they do not eat much animal food. If B12 levels get too low, people may feel very tired. It can even cause damage to the brain or nerves. Doctors can use shots or pills to help.

Vitamin B12 is a very special helper for our bodies. It is also known as cobalamin or an extrinsic factor. This vitamin is part of a group of eight B vitamins. It is the most chemically complex vitamin that we know of. It plays a vital role in our metabolism, which is how our bodies use energy.

B12 works as a cofactor to help our cells do important jobs. This means it is needed for certain reactions to happen correctly. It helps with making DNA, which is the code inside our cells. It also helps our bodies process fatty acids and amino acids.

This vitamin works in several important ways inside the body. One main job is supporting the nervous system. It helps make myelin, which is a coating for our nerves. B12 is also critical for making red blood cells. This happens in the bone marrow, which is the soft part inside our bones.

Without enough B12, red blood cells might not grow or mature correctly. This can lead to a condition called megaloblastic anemia. This type of anemia happens when DNA synthesis is blocked. It can also cause problems with how our cells grow and divide.

Tiny living things are the only ones that make true vitamin B12. These include certain bacteria and archaea. While animals need B12 to stay healthy, plants do not need it at all. Plants use different pathways to do the jobs that B12 does for animals. Humans get B12 from eating certain foods. Natural sources include meat, fish, shellfish, poultry, eggs, and dairy products.

Many people also get B12 from breakfast cereals. This is done through food fortification, which means adding nutrients to food. You can also find B12 in dietary supplements and medicines.

There are different forms of B12 called vitamers. One common form is cyanocobalamin, which is used in many supplements. It is very stable, so it does not break down easily. Other forms include methylcobalamin and adenosylcobalamin. These are the forms that are actually active in our bodies.

Some people might not get enough B12 if they do not eat animal products. Vegans and vegetarians are at a higher risk for this. In some places, like India and Hong Kong, about 80% of vegans lack enough B12. Doctors can help by giving B12 through pills or injections.

An injection can be given into a muscle to treat a deficiency.

Having enough B12 is very important for growing children and pregnant women. If a mother does not have enough B12, it can affect her baby. It can increase the risk of miscarriage or developmental delays. For babies, a lack of B12 can cause problems with growth and brain development. In adults, being low on B12 can cause many symptoms. These include feeling very tired, having trouble with memory, or feeling sad. It can even cause permanent damage to the nerves if it is not treated. Staying healthy with B12 helps our brains and bodies work their best.

Vitamin B12 is a vital nutrient known as cobalamin or extrinsic factor. It belongs to a group of eight B vitamins. This vitamin is essential for metabolism, which is how our bodies process energy. It acts as a cofactor, meaning it is required for certain enzyme-catalyzed reactions to occur.

Without this cofactor, many biological processes would stop. B12 is the most chemically complex of all known vitamins.

At its core, B12 is a coordination complex. It features a cobalt atom at its center. This cobalt atom sits inside a structure called a corrin ligand. The complex is also bound to a benzimidazole ligand and an adenosyl group.

Because of this structure, B12 can perform many different tasks. It serves as a vital helper in DNA synthesis. It also aids in the metabolism of fatty acids and amino acids. These processes keep our cells functioning and growing correctly.

There are several different forms of this vitamin, called vitamers. Each form has a specific structure based on what is attached to the cobalt. For example, methylcobalamin has a methyl group attached. This form works in the cytosol, which is the fluid inside cells. Adenosylcobalamin has an adenosyl group and works in the mitochondria.

Cyanocobalamin is a manufactured form where a cyanide group is attached. This form is very stable and is often used in food fortification and supplements. Because it is stable, it does not break down easily.

B12 is produced exclusively by certain bacteria and archaea. Animals must consume B12 through their diet to survive. Plants do not require B12 because they use different enzymatic pathways. Natural sources for humans include meat, poultry, fish, shellfish, eggs, and dairy.

Many breakfast cereals also include B12 through food fortification. People can also take B12 as dietary supplements or pharmaceutical medicines. These are often taken orally, but doctors may use intramuscular injections for treatment.

Deficiency in B12 can lead to serious health issues. One major problem is megaloblastic anemia. This happens when the body cannot perform proper DNA synthesis. This inhibition affects the production of purines and thymidine.

Another serious issue is damage to the nervous system. B12 supports the synthesis of myelin, which is the protective coating on nerves. A lack of B12 can cause neuropathy or even irreversible nerve damage. Symptoms can include fatigue, memory problems, and even psychosis.

Certain groups are at a higher risk for deficiency. Vegans are at risk because plant foods do not provide enough B12. In Hong Kong and India, roughly 80% of vegans have been found to be deficient. Vegetarians are also at risk, with studies showing 40% to 80% deficiency in those who do not use supplements. The elderly are also vulnerable. This is often due to achlorhydria, which is a reduction in stomach acid. Less acid makes it harder for the body to absorb the vitamin.

B12 is especially critical during pregnancy and childhood. Low maternal levels increase the risk of miscarriage and preterm birth. The placenta works to concentrate B12 for the developing fetus.

If a mother is deficient, her breast milk may also have low levels. This can lead to developmental delays or anemia in infants. In children, untreated deficiency can cause involuntary movements and poor physical growth. Maintaining proper levels is vital for long-term neurological health.