Vitamin B9, also called folate, is needed to manufacture DNA. Adequate levels are also required for the body to produce red blood cells.

It can also help prevent infertility issues, strokes, colorectal cancer, and macular degeneration.

Folate occurs naturally in leafy green vegetables, fruits, beans, dairy, meat, eggs, seafood, grains, and even beer.

Deficiency can result in anemia, diarrhea, depression, neuropathy, mental changes and confusion, and cardiovascular complications.4

During pregnancy, folate deficiency can result in neurological problems for the fetus.

My colleague, Jonathan Wright, M.D., was one of the first doctors to recognize the need for women to have adequate folate during pregnancy.

His work was instrumental in the RDI for folate being raised to prevent fetal neurological dysfunction.

Data from the U.S. government’s National Health and Nutrition Examination Survey (NHANES) indicate that 19 percent of female adolescents and 17 percent of women ages 19 to 30 do not get enough folate.

The best way to measure folate levels is via a red blood cell test. The RDI for folate is 400 mcg per day.

When supplementing with folate, I recommend 1 to 5 mg per day along with 1 mg of vitamin B12.

There is little chance of toxicity with folate because the body gets rid of the excess. However, folate supplementation can mask vitamin B12 deficiency, causing pernicious anemia.

For that reason, I do not recommend taking folate without the concurrent use of vitamin B12.