Folate

Folate, also called vitamin B₉, is one of the B vitamins. Our bodies need it to help make DNA and RNA and to work with amino acids. This is important for growing new cells and for blood cells to develop. Because our bodies can't make folate, we need to get it from food.

Folate, in the form of folic acid, is often added to foods or taken as a supplement. It is very important for women who are or might become pregnant. It helps prevent some serious birth problems. Many countries add folic acid to certain foods to help with this.

Not having enough folate can cause a type of anemia. This can make people feel very tired, have a fast heartbeat, and have trouble breathing. Folate was discovered between 1931 and 1943. It is now listed as an essential medicine by the World Health Organization. In 2023, it was one of the most prescribed medications in the United States.

Definition

Folate, also called vitamin B₉, has many forms such as tetrahydrofolic acid, methyltetrahydrofolate, and folinic acid. In nutrition, folates are natural vitamins in foods, while folic acid is the man-made form used in supplements.

Chemically, folates are made of three parts linked together: a pterin ring, a p-aminobenzoyl group, and glutamic acid or a chain of glutamate molecules. These parts help carry small units of carbon, which are important for building DNA and other cell functions.

Health effects

Folate is very important when the body is growing quickly, like during infancy and pregnancy. Not having enough folate can stop the body from making new cells. This can affect blood cells and growth because folate helps create DNA, the instructions inside every cell.

Having enough folate is especially important for women who are pregnant or might become pregnant. Not enough folate can lead to serious problems in a baby’s development, such as neural tube defects. Because of this, it’s recommended that women planning to have a baby take extra folate before and during pregnancy. Some countries add folate to foods like flour to help make sure people get enough. Folate also may help lower the chance of some heart problems and may play a role in preventing certain health issues. It’s also important for healthy brain function.

Absorption, metabolism and excretion

Folate from food is absorbed in the small intestine with the help of special proteins. The body changes folate into a form called tetrahydrofolate (THF). THF helps with important jobs, like making DNA and helping cells grow.

Our bodies can’t make folate on their own, so we get it from foods and supplements. Plants and some tiny organisms can make folate, but animals, including humans, need to get it from what they eat. After the body uses folate, it is removed through urine and feces.

Drug interference

Some medicines can change how the body uses folate. Drugs like trimethoprim, pyrimethamine, and methotrexate stop the body from making a form of folate that it needs.

People who drink a lot of alcohol often have less folate in their bodies. This is because alcohol makes it harder for the body to use folate properly.

Function

Folate helps the body move single-carbon groups, such as a methyl group, methylene group, or formyl group, to other molecules. This is important for making DNA and RNA. It also helps change homocysteine into methionine.

Folate is needed to help make DNA and RNA, the building blocks of cells. It also helps turn vitamin B₁₂ into a form the body can use. If there is not enough vitamin B₁₂, it can seem like there is not enough folate.

Main articles: Purine metabolism and Pyrimidine metabolism

Dietary recommendations

Folate, also called vitamin B9, helps our bodies make DNA and RNA and process amino acids. The body absorbs folic acid — a form of folate found in supplements and fortified foods — better than natural folate from food. Because of this, a special measurement called dietary folate equivalent (DFE) is used to help us understand how much folate we get from different sources.

Health organizations give guidelines for how much folate people should get each day. For example, adults need about 330 µg of folate daily, while pregnant women need more — about 600 µg. These guidelines help us make sure we get enough folate to stay healthy.

Deficiency

Folate deficiency happens when the body doesn’t get enough folate, a very important vitamin. This can happen if someone doesn’t eat enough vegetables or other foods with folate. Some diseases like Crohn's disease or celiac disease, certain genetic conditions, or some medicines such as sulfasalazine can also cause it. Drinking alcohol can make this problem happen faster.

Not having enough folate can cause some health issues, like sore or swollen tongues, diarrhea, feeling very tired, and changes in hair color. It can also make it harder for the body to make red blood cells, which can lead to a condition called megaloblastic anemia. This can make people feel weak and have trouble focusing. Doctors can test blood to see if someone has a folate deficiency. Usually, taking extra folic acid helps bring folate levels back to normal and makes people feel better.