By Dr Samira Hernandez & Tiffany Ellis

The Folic Acid Molecular Structure

Folic acid is an important nutrient for women who may become pregnant, because a woman’s blood levels of folate fall during pregnancy due to an increased maternal RBC (Red Blood Cell) synthesis in the first half of the pregnancy and fetal demands in the second half.[7] The first four weeks of pregnancy (when most women do not even realize they are pregnant) require folic acid for proper development of the brain, skull, and spinal cord.[8] Folic acid deficiency is linked to neural tube defects, such as spina bifida and anencephaly. In order to prevent these birth defects, it is recommended that all women of childbearing age supplement their diet with folic acid in a dosage of 400 mcg to 800 mcg daily. The greatest benefits of folic acid supplementation are seen within the first 6 weeks of gestation and the three months previous. Therefore, it is imperative that all women of childbearing age take the recommended supplementation of folic acid.

So what exactly is folic acid? Folic Acid, is also known as vitamin B9 [1] or folacin. Folate is the naturally occurring form, as well as pteroyl-L-glutamic acid and pteroyl-L-glutamate, which are forms of the water-soluble vitamin B9. Folic acid is itself not biologically active, but its biological importance is due to tetrahydrofolate and other derivatives after its conversion to dihydrofolic acid in the liver.[2]
Vitamin B9 (folic acid and folate inclusive) is essential to numerous bodily functions ranging from nucleotide biosynthesis to the remethylation of homocysteine. The human body needs folate to synthesize DNA, repair DNA, and methylate DNA as well as to act as a cofactor in biological reactions involving folate.[3] It is especially important during periods of rapid cell division and growth. Children and adults both require folic acid in order to produce healthy red blood cells and prevent anemia.[4]

A 2003 opinion article in the New York Times[6] named micronutrients, especially folic acid, the “world’s most luscious food,” since absence of folic acid and a handful of other micronutrients causes otherwise-preventable deformities and diseases, especially in fetal development. This article suggests that adding folic acid and micronutrients to the food supply of developing countries would have a greater impact than any other single action in improving world health.
Folate and folic acid derive their names from the Latin word folium (which means “leaf”). Leafy vegetables are a principal source of folate, although, in Western diets, fortified cereals and bread may be a larger dietary source, although this is much less nutritious than consuming leafy greens.

Certain foods are very high in folate:
? Leafy vegetables such as spinach, asparagus, turnip greens
? Legumes such as dried or fresh beans, peas and lentils
? Liver and liver products also contain high amounts of folate
? Baker’s yeast
? Fortified grain products (pasta, cereal, bread); some breakfast cereals (ready-to-eat and others) are fortified with 25% to 100% of the recommended dietary allowance (RDA) for folic acid
? Sunflower seeds

Certain foods that have moderate amounts of folate:
? Fruits, such as: orange juice, canned pineapple juice, cantaloupe, honeydew melon, grapefruit juice, banana, raspberry, grapefruit, strawberry
? Vegetables, such as: beets, corn, tomato juice, vegetable juice, broccoli, brussels sprouts, romaine lettuce, bok choy,[8]

A table of selected food sources of folate and folic acid can be found at the USDA National Nutrient Database for Standard Reference.[10] Folic acid is added to grain products in many countries, and, in these countries, fortified products make up a significant source of the population’s folic acid intake.[11] Because of the difference in bioavailability between supplemented folic acid and the different forms of folate found in food, the dietary folate equivalent (DFE) system was established. 1 DFE is defined as 1 µg of dietary folate, or 0.6 µg of folic acid supplement. This is reduced to 0.5 µg of folic acid if the supplement is taken on an empty stomach.[12]

Folic acid naturally found in food is susceptible to high heat and UV, and is soluble in water.[13] It is heat-labile in acidic environments and may also be subject to oxidation.[13]
The risk of toxicity from folic acid is low because folate is a water-soluble vitamin and is regularly removed from the body through urine.[14] The Institute of Medicine has established a tolerable upper intake level (UL) for folate of 1 mg for adult men and women, and a UL of 800 µg for pregnant and lactating (breast-feeding) women less than 18 years of age. Supplemental folic acid should not exceed the UL to prevent folic acid from masking symptoms of vitamin B12 deficiency.[15] A 10,000-patient study at Tufts University in 2007 concluded that excess folic acid worsens the effects of B12 deficiency and in fact may affect the absorption of B12.[16]

A study at the University of Adelaide concluded that the intake of folic acid supplements during late pregnancy increases the risk of babies developing childhood asthma by 30%, although researchers emphasized that their finding did not contradict recommendations to supplement folic acid in first trimester, when no additional risk was found.[17]

References:
[1] ^ Ural, Serdar H. (2008-11). “Folic Acid and Pregnancy.”. Kid’s Health.
[2] ^ a b c d Bailey SW, Ayling JE (September 2009). “The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake”. Proceedings of the National Academy of Sciences of the United States of America 106 (36): 15424–9. doi:10.1073/pnas.0902072106. PMID 19706381.
[3] ^ a b c d Weinstein SJ et al Null Association Between Prostate Cancer and Serum Folate, Vitamin B6, Vitamin B12, and Homocysteine Vol 12 pg 1271-1272 Cancer Epidemiology, Biomarkers, & Prevention November 2003
[4] ^ “Dietary Supplement Fact Sheet: Folate.”. Office of Dietary Supplements, National Institutes of Health.
[5] ^ a b Ebbing M, Bønaa KH, Nygård O, et al. (2009). “Cancer incidence and mortality after treatment with folic acid and vitamin B12″. JAMA 302 (19): 2119–26. doi:10.1001/jama.2009.1622.
[6] ^ New York Times World’s Healthiest Foods
[7] ^ a b c Barr, S. FNH 371:Human Nutrition Over the Life Span, course notes. (2009), page 19
[8] ^ a b c http://www.eatrightontario.ca/en/ViewDocument.aspx?id=109
[9]^ [1]
[10] ^ “Reports by Single Nutrients”. USDA. 2009-02-13. Retrieved 2009-03-19.
[11] ^ Dietrich M, Brown CJ & Block G (2005) The effect of folate fortification of cereal-grain products on blood folate status, dietary folate intake, and dietary folate sources among adult non-supplement users in the United States. J Am Coll Nutr 24, 266-274.
[12] ^ Suitor CW & Bailey LB (2000) Dietary folate equivalents: interpretation and application. J Am Diet Assoc 100, 88-94.
[13] ^ a b [2]
[14] ^ Hathcock JN. (1997). “Vitamins and minerals: efficacy and safety”. American Journal of Clinical Nutrition 66 (2): 427–37. PMID 9250127.
[15] ^ Baggott JE, Morgan SL, HaT, Vaughn WH, Hine RJ (1992). “Inhibition of folate-dependent enzymes by non-steroidal anti-inflammatory drugs”. Biochemical Journal 282 (Pt 1): 197–202. PMID 1540135.
[16] ^ BBC Folic acid ‘hinders malaria drug’ 21 October 2006
[17] ^ Foodproductiondaily
[18] ^ Popular Science Uh-oh: Folic Acid Linked to Rise in Childhood Asthma 4 November 2009

*THE STATEMENTS HAVE NOT BEEN EVALUATED OR APPROVED BY THE US FOOD AND DRUG ADMINISTRATION (FDA). THESE PRODUCTS ARE NOT INTENDED TO DIAGNOSE, TREAT, CURE, OR PREVENT ANY DISEASE.