Folate

Folate, also known as vitamin B₉ and folacin, is one of the B vitamins. It is very important for our bodies because it helps make DNA and RNA and process amino acids, which are needed for cell division and the growth of blood cells. Since 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 and taken as a supplement. It is especially important for women who are or might become pregnant, as it helps prevent serious birth problems called neural tube defects, such as anencephaly and spina bifida. Many countries add folic acid to certain foods to help reduce these defects.

Not having enough folate can lead to a type of anemia where red blood cells become unusually large. Symptoms can include feeling very tired, heart palpitations, and trouble breathing. Folate was discovered between 1931 and 1943 and 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 known as vitamin B₉, includes many forms such as tetrahydrofolic acid, methyltetrahydrofolate, and folinic acid. In nutrition, folates are natural vitamins found in foods, while folic acid is the man-made version 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, which can affect blood cells and growth. This is 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, which happen very early in pregnancy. 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. Studies show that this can greatly reduce the number of babies born with certain birth defects. Folate also may help lower the chance of some heart problems and may play a role in preventing certain cancers, though more research is needed. It’s also important for healthy brain function and may help with some mental health conditions.

Absorption, metabolism and excretion

Folate from food is absorbed in the small intestine using special proteins that help it enter the body’s cells. The body changes folate into a form called tetrahydrofolate (THF), which is needed for many 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, must get it from what they eat. Once inside the body, folate is used and then removed through urine and feces.

Drug interference

Some medicines can affect how the body uses folate. Drugs like trimethoprim, pyrimethamine, and methotrexate interfere with the creation of a form of folate that the body needs.

People who drink a lot of alcohol often have less folate in their bodies. This happens because alcohol makes it harder for the body to process and 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, and for creating methionine from homocysteine. These processes are part of what is called folate-mediated one-carbon metabolism.

Folate is needed to help make DNA and RNA, the building blocks of cells. It also plays a role in turning vitamin B₁₂ into a form the body can use, which helps change homocysteine into methionine. If there is not enough vitamin B₁₂, it can act like a folate deficiency.

Main articles: Purine metabolism and Pyrimidine metabolism

Dietary recommendations

Folate, also known as vitamin B9, is important for making DNA and RNA and for processing amino acids. Because the body absorbs folic acid — a form of folate used in supplements and fortified foods — better than natural folate from food, a special measurement called dietary folate equivalent (DFE) is used. This helps us understand how much folate we get from different sources.

Different health organizations set 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 ensure we get enough folate to stay healthy.

Deficiency

Folate deficiency happens when the body doesn’t get enough folate, a vital vitamin. This can occur due to eating few vegetables and other folate-rich foods, certain diseases like Crohn's disease or celiac disease, genetic conditions, or taking specific medicines such as sulfasalazine. Drinking alcohol can also speed up folate deficiency.

Not having enough folate can cause several health problems, including sore or swollen tongues, diarrhea, feeling tired, and changes in hair color. It can also affect the production of red blood cells, leading to a condition called megaloblastic anemia, which makes people feel weak and unable to focus. Doctors check for folate deficiency by testing blood levels. Treatment usually involves taking extra folic acid, which helps restore healthy levels and improve symptoms.