Date: May 1st, 2007
The B12 Catch
What Does Folate/Folic Acid Do?
Folate helps the body form red blood cells and aids in the formation of genetic material (DNA) within every body cell.
Where Do I Get It?
Folate is found in whole grains, leafy green vegetables such as spinach, oranges, strawberries, liver, shellfish, peas, yeast, and sunflower seeds. In the U.S., cereals and flour products have high levels of folic acid, which has been added since 1998 to reduce the likelihood of nervous-system birth defects. The fortification program helped reduce the rate of spina bifida by 25% in six years.
How Much Folic Acid Do I Need?
The Food and Drug Administration recommended daily allowance (RDA) of folic acid for healthy adults is 400 micrograms. A cruise of your pantry shelves will quickly tell you how much your breakfast cereal is packing - anywhere from 25% to 100% of the RDA. Two slices of wheat bread contain about 10%. If you are eating a balanced diet, chances are you're getting more than the RDA.
Some medical conditions can increase the need for folate. Some medical conditions such as alcohol abuse, kidney dialysis, liver disease, and certain anemias can cause a folate deficiency. Medications may also interfere with the body's use of folate, such as some anti-convulsant drugs. A list of such drugs can be found at the National Institutes of Health.
Too Much of a Good Thing: The B12 Catch
You probably already have enough folate in your diet, thanks to the fortification program. Most U.S. diets now provide the RDA, according to a study in the January 2007 edition of the American Journal of Clinical Nutrition.
The Institute of Medicine of the National Academy of Sciences has set 1000 micrograms as the upper limit of folic acid to be ingested daily from fortified foods or supplements. The upper limit refers to the intake from fortified foods or pills; there is no health risk for natural sources of folate, such as vegetables.
Ingesting more than 1000 micrograms can have serious health consequences. Excessive folic acid may mask a vitamin B12 deficiency, which can result in anemia and cognitive impairment, particularly in seniors.
If you are 50 years of age or older, ask your physician to check your B12 status before you take a supplement that contains folic acid. If you are taking a supplement containing folic acid, make sure it also contains B12 or speak with a physician about the need for a B12 supplement.