Source: Thailand Medical News Dec 01, 2019 4 years, 11 months, 3 weeks, 1 day, 29 minutes ago
Dietary Supplements
Folate 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.
Vitamin B9 or
Folate 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.
Though
folate 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.
Vitamin B9 or
Folate, 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.
Supplementation 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 in
supplements 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 B9
Vitamin B9 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
Folic acid 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 B
12 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 B
12.
Drug interactions
Folate supplements 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.
Conclusion
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.
References:
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