While the nutritional supplement folate (also known as folic acid or vitamin B9) can be useful for depression, there appears to be one instance when augmentation with regular folate could be counterproductive. In those with a transport defect associated with a MTHR (methyl tetrahydrofolate reductase) deficiency, folate can compete with l-methylfolate for uptake into the brain. Folate would thus limit the beneficial effects of l-methylfolate supplementation, which is required for this 15% of the population.
A study of 85,000 children in Norway that was recently published in the Journal of the American Medical Association showed that women who took folic acid during pregnancy were 40% less likely to have a child who developed autism.
A summary of the research by National Public Radio explained:
Folic acid is the synthetic version of a B vitamin called folate. It’s found naturally in foods such as spinach, black-eyed peas and rice. Public health officials recommend that women who may become pregnant take at least 400 micrograms of folic acid every day to reduce the chance of having a child with spina bifida.
The folic acid’s effect reduced the most severe cases of autism but did not seem to have an effect on the incidence of more mild forms, such as Asperger syndrome. The benefits were seen in those women who had been taking folic acid for 4 weeks before conception and continued to take the supplement during the first 8 weeks of pregnancy.
The B vitamin folate has been shown to be a useful augmentation treatment for patients who are nonresponsive or only partially responsive to selective serotonin reuptake inhibitor (SSRI) antidepressants. Treatment with folate works even in those who are not folate-deficient at baseline.
When folate is broken down in the body by reductase enzymes, it turns into the active form L-methylfolate, and crosses the blood-brain barrier. Giovanni Fava and colleagues at Massachusetts General Hospital (MGH) performed two placebo-controlled, randomized studies of L-methylfolate for depression. There was significantly greater improvement when SSRIs were augmented with L-methylfolate than when they were augmented with placebo. The results were significant with the use of 15mg of L-methylfolate, but not with 7.5mg, suggesting dose-related effects. Read more