What Is the Function of Folic Acid?

Breakfast cereals and processed grains are fortified with folic acid.
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Folic acid is the supplemental, inactive form of the naturally occurring B vitamin folate. Once absorbed into your body, folic acid is converted into metabolically active folate. Folate is a required cofactor in several important metabolic processes, meaning these chemical reactions do not occur unless folate is present. Make sure you incorporate 400 micrograms of folic acid or folate in your diet daily to prevent a deficiency.

Red Blood Cell Production

Your bone marrow produces more than 65 million new red blood cells each day for every 10 pounds of body weight. This remarkable production rate requires a constant supply of folate, iron, vitamin B-12 and other nutrients. If you have a folate deficiency, the formation of genetic material to produce new red blood cells slows, leading to decreased bone marrow productivity. As old red blood cells die, there are not enough new cells to take their place, which eventually can lead to anemia. Replenishing your body's folate supply reverses this form of anemia. Spinach, Brussels sprouts, collards and other greens are rich sources of natural folate.

Nervous System Development

The necessity of folate to produce new cells is particularly important during the early weeks of pregnancy, when the brain and spinal cord form. A folate deficiency during this period increases the risk of nervous system birth defects, specifically, anencephaly and spina bifida. With anencephaly, the brain fails to develop normally, often resulting in miscarriage or stillbirth. Babies born alive with anencephaly typically die shortly after birth. Spina bifida describes abnormal development of the lower spinal cord, which varies in severity. The defect is minor in some babies, but severe spina bifida may cause paralysis below the level of the spinal cord abnormality. Folic acid is added to processed cereal grains in the United States to reduce the incidence of nervous system birth defects caused by a deficiency of this vitamin.

Amino Acid Metabolism

Your body uses amino acids to build proteins, converting amino acids into other chemicals with the help of folate-dependent cofactors. The conversion of homocysteine to methionine is one important example of folate-dependent amino acid metabolism. Folate deficiency impedes this conversion, leading to a buildup of homocysteine in your bloodstream. Elevated homocysteine levels are associated with an increased risk of developing cardiovascular disease.

Regulation of Gene Expression

Every cell of your body carries the same genetic information. The function and metabolic activity of any given cell is a reflection of what genes are active, or expressed. Folate is involved in a chemical reaction that keeps genes "silent." Folate deficiency may lead to loss of this mechanism to control gene expression. Folate-dependent control of gene expression may influence your risk of developing cancer and is the focus of ongoing biomedical research.