Folic Acid: Uses, Dosage, and Side Effects

• Folic acid, also known as vitamin B9, is a supplement used to treat folate deficiency.
• Can be used for megaloblastic anemia (macrocytic anemia) that stems from folic acid deficiency.
• Supplementing folic acid in instances of vitamin B12 deficiency helps to re-establish hematopoiesis.
• Folate deficiencies related to diet may be corrected through increased consumption of folate-rich foods like legumes, citrus fruits, and nuts.

Use Cases

• Treats folate deficiency resulting from alcohol use disorder or malabsorption syndromes.
• Can be given alone or with vitamin B12, to treat megaloblastic anemia, depending on the cause.
• Prevents neural tube defects in the developing fetus when taken by women of childbearing age, before and during pregnancy.

Pharmacologic Action

• Folic acid is essential for both DNA and RNA synthesis, which is fundamental for cell replication in all body tissues.
• Necessary for erythropoiesis but requires conversion to tetrahydrofolic acid after ingestion.

Adverse Reactions

• May cause urine to turn an intense yellow color.
• Long-term consumption may increase the risk of certain cancers.
• Daily intake should be limited to 1000 mcg to prevent masking vitamin B12 deficiency and potential neurological deficits.

Interventions

• Encourage the consumption of a diet high in folic acid, including green vegetables, liver, lentils, and fortified breakfast cereals.
• Monitor for manifestations of megaloblastic anemia and plasma folic acid levels.

Administration

• Folic acid deficiency is usually treated with an increase in dietary forms of folic acid.
• Additional replacement therapy may be administered orally, subcutaneously, intramuscularly, or intravenously, with oral being the most common.
• Before initiating therapy, confirm the absence of vitamin B12 deficiency to avoid potential permanent neurological damage if only treated with folic acid.
• Obtain baseline serum folate, hemoglobin, hematocrit, red blood cell, and reticulocyte counts, and monitor periodically thereafter.
• Expect hematocrit counts to improve within 2 weeks.
• Counsel clients with alcohol-related malnutrition to avoid alcohol and encourage dietary intake of foods high in folate, such as green vegetables and liver.

Client Instructions

• Follow diet changes to treat folic acid deficiency.
• Report any rash development following oral or IV administration, as it may indicate hypersensitivity to the medication.

Contraindications and Precautions

• Do not use as the sole treatment for pernicious anemia, but can be used as adjunctive therapy.
• Avoid usage for non-folic acid related anemias and in neonates.

Safety Alert

• Folic acid can contribute to the restoration of hematopoiesis but will not maintain the myelin sheath of neurons, potentially leading to neuronal damage.
• The presence or absence of a vitamin B12 deficiency should be determined when administering folic acid to correct megaloblastic anemia in order to prevent neuronal damage from concurrent administration.

Interactions

• Can mask the manifestations of B12 deficiency; clients with a B12 deficiency must take adequate doses of cyanocobalamin to prevent neurological damage.
• Medications like oral contraceptives, corticosteroids, or methotrexate may cause manifestations of folic acid deficiency.

Folic acid, or vitamin B9, treats folate deficiency and megaloblastic anemia. It's crucial for DNA and RNA synthesis, essential for cell replication. Supplementation helps restore hematopoiesis in vitamin B12 deficiencies and prevents neural tube defects during pregnancy.