is a water soluble B vitamin also known as B9
and folacin, folate is a naturally occurring nutrient in foods, while folic acid
is the synthetic form found in enriched foods and dietary supplements.
is best known for its role in the prevention of neural tube defects (NTDs) , which are birth defects of the brain and spine, specifically anencephaly and spina bifida. Folate
also is an essential nutrient for enzyme reactions in protein and vitamin metabolism, as well as DNA and RNA synthesis.
Besides reducing the risk of NTDs, folate is crucial in decreasing the risk of pregnancy complications including anemia, preterm birth, congenital heart defects and oral clefts.
is vital early in pregnancy during rapid cell division, growth and development, approximately 35 percent of non-pregnant women do not meet dietary intake recommendations of folate
without the use of dietary supplements
Cilnical trials show roughly 90 percent of NTDs and 40 percent of congenital heart anomalies are preventable when women of childbearing age supplement with 400 to 800 micrograms of folic acid
for four weeks pre-conception and eight weeks post-conception. Timing is critical, as neural tube defects occur in the first few weeks of pregnancy.
The U.S. Food and Drug Administration in 1998, mandated folic acid
fortification of enriched grain products to reduce NTDs. In 2016, the FDA approved the voluntary inclusion of corn masa flour to help Latinas who have a higher prevalence of NTDs. Folic acid
fortification of grains has prevented NTDs in approximately 1,300 babies each year, and NTDs in the U.S. have declined by 35 percent since 1998.
, along with vitamins B6 and B12, has been studied for its protective role in age-related cognitive decline with mixed results. Inadequate folate
consumption may increase dementia.
There is an association between low blood folate
levels and depression and response to antidepressant medication, but more research is needed to understand the relationship.
with Folic acid
can impact levels of homocysteine, an amino acid in the blood that, when high, is a risk factor for heart disease. However, folic acid
’s role in reducing the risk of cardiovascular disease is unproven.
Many entities including the U.S. Preventive Services Task Force recommend women consume a supplement with a minimum of 400 to 800 micrograms of folic acid
if they are capable of becoming pregnant. In 2017, after a thorough review of the literature, the USPSTF confirmed this recommendation. Women with a history of NTDs are advised to supplement
with 4,000 micrograms
of folic acid
, in addition to folate
from a varied diet.
The RDA or recommended dietary allowance is in dietary folate
equivalents, or DFE, because folic acid
and fortified foods is more easily absorbed (1 microgram DFE equates to 1 microgram folate and 0.5 to 0.6 microgram folic acid). Bioavailability of supplemental folic acid
is 100 percent when consumed on an empty stomach and 85 percent when consumed with food, while the bioavailability of folate
from food sources is estimated to be about 50 percent.
Sources of Vitamin
occurs naturally in a variety of foods, and many foods are fortified with folic acid
. Folic acid
is available in multivitamins, prenatal vitamins, singularly and in B-complex dietary supplements.
Symptoms of deficiency
deficiency is rare in the United States, but can be caused by inadequate dietary intake, alcoholism, smoking and conditions that alter nutrient absorption. People with the MTHFR genetic polymorphism are unable to convert folate
to the active form.
Symptoms of deficiency include sores in the mouth and changes in skin color, hair and fingernails. Inadequate intake of folate
or vitamin B12
can result in megaloblastic anemia with symptoms including fatigue, weakness and shortness of breath.
Excessive Dosing or Toxicity
Toxicity could result by exceeding the UL with folic acid
supplements. High doses of folic acid supplements
could lead to un-metabolized folic acid
and may mask pernicious anemia, in which the body cannot properly absorb vitamin B12
may interfere with methotrexate, reduce blood levels of anti-epileptic and anti-seizure medications, and lower serum folate
levels. Sulfasalazine, used for ulcerative colitis, and cholesterol-lowering agents may impair folate
absorption and cause deficiency.
It should be noted that diet alone may not provide adequate folate
for women of reproductive age. Those women should eat a folate
-rich diet and take folic acid supplements
at least one month before conception and continuing throughout pregnancy.
When buying folate supplements
, stay away from brands that are made in Asia. Thailand Medical
News recommends buying supplements from the company Now Foods or Life Extension that are manufactured under stringent guidelines in the US.
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