Folic Acid (folate), folinic acid, Vitamin B9

spinachFolate in its biologically active form is either 5-methyl-tetrahydrofolate or tetrahydrofolate.  In conjunction with vitamin B12, it donates the methyl group to homocysteine to make it methionine.  This is the key step in the methylation cycle, needed to produce methyl groups that are required for the formation of all proteins and enzymes, the production of neurotransmitters, and it helps remove excessive homocysteine. It is also vital in one carbon metabolism of nucleic acids and amino acids. Methylation of RNA and DNA is not only essential for the normal growth and development of the unborn child’s brain and body, but for everyone’s ongoing health and cancer prevention. 



The initial evidence of folate deficiency can be seen in the blood where anemia develops with larger red blood cells (RBC’s), and as this progresses, you may have fatigue, weakness, and shortness of breath. Other generalized symptoms associated with low folate may include anorexia, constipation, and neurological issues like headaches, insomnia, memory impairment, paranoia, or restless legs. 

The major concerns when there is low folate during pregnancy have to do with the baby’s brain development. Neural tube defects can result in a lack of brain development (anencephaly), neural tube defects, or spin bifida. Heart defects and limb malformations have also been reported .  The high homocysteine associated with low folate is associated with cardiovascular diseases like stroke, arteriosclerosis, and heart attacks. Folate, with it’s methylation support, also promotes improved removal of toxins and reduces cancer risk and the risk of Alzheimer’s and dementia. 



The best food sources for folate are green leafy vegetables and legumes (beans and lentils). Folate is added to breakfast cereals and white rice and pastas. Nuts, seeds, wheat germ, liver, and nutritional supplements also provide folate. 

There is an important point with folate supplementation and B12 status. If you exceed 1 gram (1000 micrograms) of folate daily, it can cause a B12 deficiency with serious neurological issues, though this is rare. For this reason, you should supplement B12 when you supplement folic acid, and this will help to avoid this issue. 

I strongly recommend you choose to supplement with methyl-folate rather than folic acid or plain folate. 



There is no toxicity if your intake if food based.  If you are supplementing extra folate, the major concerns come when large doses (above 1-5 grams) can mask the detection of the megaloblastic anemia of B12 deficiency and allow a B12 deficiency to progress undetected. Supplementing methyl-B12 will also avoid this issue. 



Infants                   not determined (I would recommend 200 micrograms a day)
Children                       400-800 micrograms 
Teens/adults                 1000 micrograms  


Unless your diet is high in folate foods, or you have micronutrient testing showing your levels are adequate, consider adding this at 400-1000 micrograms a day along with methyl-B12. Always take folate in your prenatal vitamin, even if your diet seems adequate. 

More about Folate from the Linus Pauling Institute…

You can also read my previous blog post about folate here…


Dr. Paul








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