What types of Folic Acid are there?
Folic acid – This is the synthetic form found in multi vitamins and many prenatal vitamins. It is readily absorbed but not as efficiently utilized by the body. It is good for:
- People who do not have the MTHFR gene mutation. For these individuals, regular folic acid is well absorbed and utilized.
- As an initial or supplementary source of folate during early pregnancy. Folic acid helps ensure adequate levels are reached in the first few weeks to months.
L-5-Methyltetrahydrofolate (L-5-MTHF) – The biologically active form that is better utilized, especially for those with MTHFR mutations. Good for:
- Individuals who have a MTHFR gene mutation. These variants impair the body’s ability to convert folic acid to its active form, so methylfolate bypasses this step.
- Women with a family history of neural tube defects in their pregnancies. The biologically active methylfolate helps ensure optimal folate levels for fetal development.
5-Methyltetrahydrofolate (5-MTHF) – Similar benefits as L-5-MTHF. Slightly better absorbed in some studies. Good for:
- People in similar groups as L-5-MTHF: those with MTHFR mutations and women at higher risk for neural tube defects.
In summary, regular folic acid is ideal as an initial or supplementary source of folate for most people. But for those with MTHFR mutations or a higher risk pregnancy, one of the methylfolate forms – L-5-MTHF or 5-MTHF – will provide the most benefit due to their increased bioavailability and utilization.
The key is determining which you fall into based on your genetic profile and reproductive health history. Then choosing a folate supplement that matches their specific needs and situation.
Here are some additional interactions and toxicity concerns with high-dose folic acid supplementation:
- Diuretics: Furosemide and hydrochlorothiazide can increase urinary excretion of folate, potentially decreasing its levels in the body.
- Oral contraceptives: Some research suggests birth control pills may decrease folate levels by interfering with absorption and metabolism.
- Selective serotonin reuptake inhibitors (SSRIs): SSRIs have been associated with lower folate levels, though the mechanism is unclear.
Folic Acid Toxicity Concerns:
- Seizure risk: There is some evidence that high doses of folic acid (above 1 mg/day) may lower the seizure threshold, potentially provoking seizures in susceptible individuals.
- Cancer progression: Researchers have theorized that high folate levels may facilitate the growth and metastases of existing, undiagnosed cancers. However, evidence is limited and inconclusive.
- Vitamin B12 deficiency masking: Folic acid supplementation may mask symptoms of vitamin B12 deficiency, delaying its diagnosis and treatment. Regular B12 tests are advised.
- Drug resistance: High folic acid levels may reduce the efficacy of some drugs like methotrexate by interfering with their mechanisms of action.
Overall, for most people, folic acid doses up to 1 mg/day from food and supplements appear safe with few interactions or side effects. However, those taking high-dose supplements (over 5 mg/day), women with MTHFR mutations or individuals on certain medications may be at higher risk of issues.
As always, discussing supplementation plans with your healthcare provider is advised to identify any potential concerns, avoid complications and determine the most appropriate folic acid intake based on your individual circumstances and health goals.