Folic acid (also known as folate or vitamin B9) is essential for the body to build and repair DNA. The body can store only about 15 milligrams total—even when stores are fully replenished, that supply lasts roughly three months at most. Humans cannot produce folic acid themselves.
A substantial portion of adults in the US consumes less than the recommended 400 micrograms of folate (in dietary folate equivalents, DFE) per day from natural food sources alone—though fortification of cereals and grains has raised total intakes for many people. The official recommendation for adults is 400 mcg DFE daily. Among heavy drinkers and those with alcohol use disorder, the situation is far worse. Alcohol blocks folic acid absorption in the intestines. Even what little gets through is poorly stored in the liver—alcohol suppresses that process too. With alcohol present, the kidneys cannot retain folic acid effectively, so the body loses this vital vitamin much more rapidly through urine.
Folic acid deficiency promotes fatty liver disease. With adequate folic acid, the body converts homocysteine into the amino acid methionine. Without enough folic acid (or vitamin B12), this conversion fails, homocysteine levels rise, and the risk of cardiovascular disease increases. In addition, it disrupts red blood cell production, leading to characteristic forms of anemia.
Folic acid also plays a key role in cell division and the formation of nervous tissue. That is why sufficient supply is especially critical during pregnancy to prevent neural tube defects in the developing baby. For adults’ brains, folic acid is equally important: deficiency contributes to low mood, memory issues, and poor concentration—symptoms that often overlap with and worsen in people struggling with alcohol dependence.
Chronic alcohol consumption hits the problem from multiple angles: impaired absorption, blocked storage, and increased excretion. The result is particularly low folic acid levels, sharply raising the risk for anemias, fatty liver, cardiovascular diseases, and neurological problems. Many classic complaints in alcohol-dependent individuals—from persistent fatigue and depressive moods to lack of drive—can partly trace back to severe folic acid depletion.
In treatment, people with alcohol use disorder are therefore often given high-dose folic acid supplementation, usually combined with other B vitamins such as B12 and B6. This approach helps stabilize blood formation and lowers the risk of long-term damage.
Bernd Guzek, MD, PhD #
Physician, author & co-founder of Bye-Bye-Booze
Specialized in biochemical mechanisms of addiction and brain metabolism.
