Folic Acid

Folic acid, or folate, is the chemical name for a vitamin also known as vitamin B9 or vitamin M, which doctors prescribe for anemia.

Folic acid is one of the eight vitamins in the vitamin-B complex.

Like all B vitamins, folic acid plays important role in maintaining the health of your nervous system and helping you process fats and carbohydrates.

Folic Acid in Foods

Certain cereals, breads, and leafy greens, such as spinach, kale, and Swiss chard, are high in folic acid.

Other good sources of folic acid include rice, pasta, and citrus fruits, such as grapefruit, lemons, and oranges.

Folic Acid Deficiency

Folic acid plays an important role in developing the spine and nervous system of a developing a baby before birth.

A woman who consumes less than 400 micrograms (mcg) of folic acid a day is more likely to bear a child with a brain, spine, or spinal cord defect, or a neural tube defect, than a woman who gets more.

Most daily prenatal vitamins contain 800 to 1,000 mcg of folic acid.

Folic Acid and Anemia

Lack of folic acid in your diet can cause anemia, or not enough red blood cells for good health.

Even if you are consuming enough folic acid, taking certain drugs can deplete it. These drugs include:

• Methotrexate (Trexall, Rheumatrex)
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, naproxen, or diclofenac
• Many antibiotics
• Diuretics or water pills
• Certain ulcer medications
• Exenatide (Byetta, Bydureon)

Folic Acid and Hair Growth

Since folic acid, like all B vitamins, is important for the growth of the cells that form hair, skin, and nails, having adequate levels of folic acid in your body may improve growth of these tissues.

Some data suggests that correcting folic acid levels might help reverse certain types of hair loss.

Many vitamins for supporting hair, skin, and nail growth contain folic acid.

Folic Acid Warnings

Please talk to your doctor before taking folic acid if you:

• Have anemia or think that you might be anemic
• Are allergic to folic acid or any component found in the supplement you're considering taking

Pregnancy and Folic acid

Folic acid has different safety ratings for pregnancy, depending on the dose you are taking.

If you're taking a folic acid in the amount recommended for your age and condition, the supplement is safe to take in pregnancy because it doesn't cause any birth defects.

However, if you're taking a higher amount of folic acid than is usually recommended for your age and condition, the supplement is not safe to take during pregnancy.

Folic acid is safe to take while you are breastfeeding.

Tell your doctor if you are pregnant, planning to become pregnant, or are breastfeeding.

Most over-the-counter supplements of folic acid are 400 mcg tablets.

Prescription folic acid for pregnant women is usually for 1 mg (i.e., 1,000 mcg) tablets.

Adults over 18, including pregnant women, should not take more than 1,000 mcg of folic acid a day.

Boys and girls 14 to 18 years old should not take more than 800 mcg; those ages 9 to 13 should not take more than 600 mcg.

Folic acid Overdose

People taking too much folic acid may have the following complaints:

• Weakness
• Fatigue
• Poor concentration
• Confusion
• Numbness or tingling

If you suspect an overdose, contact a poison control center or emergency room immediately.

You can contact a poison control center at (800) 222-1222.

Missed Dose of Folic acid

Take the missed dose as soon as you remember it.

If it's almost time for the next dose, skip the missed dose and take your next dose at the regular time.

Do not take two doses of folic acid at the same time.

Absorption

Bioavailability

Well absorbed from the GI tract.a Synthetic folic acid is almost 100% bioavailable following oral administration in fasting individuals; folate in food is about 50% bioavailable.140

Food

Synthetic folic acid is 85–100% bioavailable following oral administration with a meal.140

Distribution

Extent

Distributed into all body tissues including the CNS; stored mainly in the liver.a

Elimination

Metabolism

Metabolized in the liver.a

Elimination Route

Up to 90% of a dose in urine; small amounts in feces.a

Storage

Oral

15–30°C.a

Parenteral

15–30°C.b

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

• Folic acid is prepared synthetically.a 140 Naturally occurring conjugates of folic acid (food folate; pteroylpolyglutamates) are present in a wide variety of foods, particularly liver, kidneys, yeast, leafy green vegetables, other vegetables, citrus fruits and juice, and legumes.140

• An exogenous source of folate is required for nucleoprotein synthesis and the maintenance of normal erythropoiesis.a

• Folic acid is not metabolically active as such, but is the precursor of tetrahydrofolic acid which is involved as a cofactor for 1-carbon transfer reactions in the biosynthesis of purines and thymidylates of nucleic acids.a

• Folate supplementation before and during pregnancy associated with a reduction in risk for fetal neural tube defects.140

Allergic sensitization has been reported following both oral and parenteral administration of Folic Acid.

Folic Acid is relatively nontoxic in man. Rare instances of allergic responses to Folic Acid preparations have been reported and have included erythema, skin rash, itching, general malaise, and respiratory difficulty due to bronchospasm. One patient experienced symptoms suggesting anaphylaxis following injection of the drug. Gastrointestinal side effects, including anorexia, nausea, abdominal distention, flatulence, and a bitter or bad taste, have been reported in patients receiving 15 mg Folic Acid daily for 1 month. Other side effects reported in patients receiving 15 mg daily include altered sleep patterns, difficulty in concentrating, irritability, overactivity, excitement, mental depression, confusion, and impaired judgement. Decreased vitamin B12 serum levels may occur in patients receiving prolonged Folic Acid therapy.

In an uncontrolled study, orally administered Folic Acid was reported to increase the incidence of seizures in some epileptic patients receiving phenobarbital, primidone, or diphenylhydantoin. Another investigator reported decreased diphenylhydantoin serum levels in folate-deficient patients receiving diphenylhydantoin who were treated with 5 mg or 15 mg of Folic Acid daily.

Oral administration is preferred. Although most patients with malabsorption cannot absorb food folates, they are able to absorb Folic Acid given orally. Parenteral administration is not advocated but may be necessary in some individuals (e.g., patients receiving parenteral or enteral alimentation). Doses greater than 0.1 mg should not be used unless anemia due to vitamin B12 deficiency has been ruled out or is being adequately treated with a cobalamin. Daily doses greater than 1 mg do not enhance the hematologic effect, and most of the excess is excreted unchanged in the urine.

The usual therapeutic dosage in adults and children (regardless of age) is up to 1 mg daily. Resistant cases may require larger doses.

When clinical symptoms have subsided and the blood picture has become normal, a daily maintenance level should be used, i.e., 0.1 mg for infants and up to 0.3 mg for children under 4 years of age, 0.4 mg for adults and children 4 or more years of age, and 0.8 mg for pregnant and lactating women, but never less than 0.1 mg/day. Patients should be kept under close supervision and adjustment of the maintenance level made if relapse appears imminent.

In the presence of alcoholism, hemolytic anemia, anticonvulsant therapy, or chronic infection, the maintenance level may need to be increased.

Refer to adult dosing. Vitamin B12 deficiency must be ruled out before initiating folate therapy due to frequency of combined nutritional deficiencies: RDA requirements (1999): 400 mcg/day (0.4 mg) minimum.

Oral preferred, but may also be administered by deep IM, SubQ, or IV injection.

IV administration: May administer ≤5 mg dose undiluted over ≥1 minute or may dilute ≤5 mg in 50 mL of NS or D5W and infuse over 30 minutes. May also be added to IV maintenance solutions and given as an infusion.

Falsely low serum concentrations may occur with the Lactobacillus casei assay method in patients on anti-infectives (eg, tetracycline)

You should not use this medication if you have ever had an allergic reaction to folic acid.

Before you take folic acid, tell your doctor if you have kidney disease (or if you are on dialysis), an infection, if you are an alcoholic, or if you have any type of anemia that has not been diagnosed by a doctor and confirmed with laboratory testing.

Talk to your doctor about taking folic acid during pregnancy or while breast-feeding. Folic acid is sometimes used in combination with other medications to treat pernicious anemia. However, folic acid will not treat Vitamin B12 deficiency and will not prevent possible damage to the spinal cord. Take all of your medications as directed.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.