Folic Acid

Are there any interactions with medications?

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5-Fluorouracil
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

There is some concern that taking large amounts of folic acid with 5-fluorouracil might increase some side effects of 5-fluorouracil, especially stomach problems. Talk with your healthcare provider before taking folic acid.

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Capecitabine (Xeloda)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

There is some concern that taking large amounts of folic acid might increase the side effects of capecitabine, especially stomach problems like diarrhea and vomiting. Talk with your healthcare provider before taking folic acid.

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Fosphenytoin (Cerebyx)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Fosphenytoin (Cerebyx) is used for seizures. The body breaks down fosphenytoin (Cerebyx) to get rid of it. Folic acid can increase how quickly the body breaks down fosphenytoin (Cerebyx). Taking folic acid along with fosphenytoin (Cerebyx) might decrease the effectiveness of fosphenytoin (Cerebyx) for preventing seizures.

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Methotrexate (MTX, Rheumatrex)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Methotrexate (MTX, Rheumatrex) works by decreasing the effects of folic acid in the body's cells. Taking folic acid pills along with methotrexate might decrease the effectiveness of methotrexate (MTX, Rheumatrex).

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Phenobarbital (Luminal)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Phenobarbital (Luminal) is used for seizures. Taking folic acid can decrease how well phenobarbital (Luminal) works for preventing seizures.

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Phenytoin (Dilantin)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

The body breaks down phenytoin (Dilantin) to get rid of it. Folic acid might increase how quickly the body breaks down phenytoin (Dilantin). Taking folic acid and taking phenytoin (Dilantin) might decrease the effectiveness of phenytoin (Dilantin) and increase the possibility of seizures.

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Primidone (Mysoline)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Primidone (Mysoline) is used for seizures. Folic acid might cause seizures in some people. Taking folic acid along with primidone (Mysoline) might decrease how well primidone works for preventing seizures.

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Pyrimethamine (Daraprim)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Pyrimethamine (Daraprim) is used to treat parasite infections. Folic acid might decrease the effectiveness of pyrimethamine (Daraprim) for treating parasite infections.

Dosing considerations for Folic Acid.

The following doses have been studied in scientific research:

BY MOUTH:

• For folic acid deficiency: the typical dose is 250-1000 mcg (micrograms) per day.
• For preventing neural tube defects: at least 400 mcg of folic acid per day from supplements or fortified food should be taken by women capable of becoming pregnant and continued through the first month of pregnancy. Women with a history of previous pregnancy complicated by such neural tube defects usually take 4 mg per day beginning one month before and continuing for three months after conception.
• For reducing colon cancer risk: 400 mcg per day.
• For treating high levels of homocysteine in the blood:
• 0.5-5 mg (milligrams)/day has been used, although 0.8-1 mg/day is appears to be more effective.
• In people with end-stage renal disease, high homocysteine levels may be more difficult to treat, and doses of 0.8-15 mg/day have been used. Other dosage plans such as 2.5-5 mg 3 times weekly have also been used. Doses higher than 15 mg daily do not seem to be more effective.
• For improving the response to medications for depression: 200-500 mcg daily has been used.
• For vitiligo: 5 mg is typically taken twice daily.
• For reduction of toxicity associated with methotrexate therapy for rheumatoid arthritis (RA) or psoriasis: 1 mg/day is probably enough, but up to 5 mg/day may be used.
• For preventing macular degeneration: folic acid 2.5 mg, vitamin B12 (cyanocobalamin) 1000 mcg, and vitamin B6 (pyridoxine) 50 mg daily.

The adequate intakes (AI) for infants are 65 mcg for infants 0-6 months and 80 mcg for infants 7-12 months of age. The recommended dietary allowances (RDAs) for folate in DFE, including both food folate and folic acid from fortified foods and supplements are: Children 1-3 years, 150 mcg; Children 4-8 years, 200 mcg; Children 9-13 years, 300 mcg; Adults over 13 years, 400 mcg; Pregnant women 600 mcg; and breast-feeding women, 500 mcg. The tolerable upper intake levels (UL) of folate are 300 mcg for children 1-3 years of age, 400 mcg for children 4-8 years, 600 mcg for children 9-13 years, 800 mcg for adolescents 14-18 years, and 1000 mcg for everyone over 18 years of age.