Folic Acid

Introduction

Folic acid is a member of the water-soluble B vitamin group. Isolated in 1946 from spinach leaves, its name comes from folium, the Latin word for leaf. In the body, folic acid is converted to a more biologically active form.

Folic acid occurs in a wide variety of foods. Best sources include dark green leafy vegetables, brewer’s yeast, liver, and eggs. Other good sources are beets, broccoli, brussels sprouts, orange juice, cabbage, cauliflower, cantaloupe, kidney and lima beans, wheat germ, and whole grain cereals and breads. The body’s “friendly” intestinal bacteria also produce folic acid.

Dosage Info

Dosage Range

200-800mcg daily. However, physicians may occasionally administer doses to severely deficient patients ranging from 5,000-15,000mcg daily. (1)

Most Common Dosage

400mcg daily.

Dosage Forms

Tablets, capsules, liquids, liposomal sprays, and effervescent tablets.

Interactions and Depletions

Interactions

• Aluminum and magnesium containing antacids
• Bile acid sequestrants
• H-2 receptor antagonists
• Potassium-sparing diuretics

Depletions

• Alcoholic beverages
• Anticonvulsants
• Salicylates
• Corticosteroid medications
• Nonsteroidal anti-inflammatory medications (NSAIDs)
• Oral contraceptives
• metformin
• methotrexate
• Trimethoprim-containing antibiotics
• sulfasalazine

Reported Uses

Like vitamin B₁₂, folic acid is necessary for the production of both DNA and RNA. It is therefore essential for proper cellular division and the transmission of the genetic code to all newly formed cells. It is also essential for the health of red blood cells (2) and the production of proteins and various amino acids.

In women, folic acid is crucial for closure of the fetus’ neural tube during pregnancy. This makes adequate folic acid levels essential for preventing neural tube birth defects such as spina bifida. (3) , (4) , (5) In general, pregnancy increases a woman’s requirements for folic acid. (6) , (7) Women with higher intakes of folic acid may have a reduced risk of ovarian cancer. (8) Also, of importance to women, folic acid may treat cervical dysplasia and decrease the necessity of hysterectomies. (9)

Studies also suggest that many people with major depression or schizophrenia may benefit from folic acid supplementation. (10) Benefit may also be extended to alcoholics, who are commonly deficient in folic acid. (11) One form of anemia that arises from folic acid deficiency can also be reversed with supplementation. (12)

 

Studies have shown cognitive skills such as knowing, thinking, learning, and judging can be impaired in older adults with low levels of certain B vitamins. Supplementation with folate, vitamin B12, and vitamin B6 has been effective in enhancing cognitive performance in older adults. (13) In fact, studies in older adults noted that subjects with low levels of vitamin B12 or folate had more of a risk of developing Alzheimer’s disease. (14) , (15)

Folic acid can also lower homocysteine levels, even when the levels are increased by lipid lowering medications. (16) , (17) , (18) , (19) , (20) Because homocysteine is an amino acid that is a significant risk factor for atheroslerosis, folic acid may prevent the development and progression of the disease. (21) The same effect has been noted when folic acid is given in conjunction with vitamin B6. (22) Hemodialysis patients were treated with B-vitamins and folic acid which significantly lowered homocysteine levels. (23) Dietary supplementation with the B-vitamins prevented hyperhomocysteinemia but did not prevent the development of vascular dysfunction or atherosclerotic lesions. (24) Other studies involving hundreds of patients who had undergone successful coronary angioplasty have evaluated these individuals following six months of therapy on vitamin B6, vitamin B12, and folic acid, comparing the results to patients on placebo. After one year, the patients on the vitamin therapy had lower rates of related cardiovascular events including heart attacks and repeated angioplasty. (25) , (26) Homocysteine can also interfere with normal bone structure, folic acid’s homocysteine-lowering function may also be of benefit in the prevention of osteoporosis. (27) , (28) , (29)

Finally, folic acid in mouthwash form may offer treatment for inflammation of the gums, or gingivitis. (30)

Toxicities & Precautions

Introduction

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General

This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Large doses of this dietary supplement may mask vitamin B₁₂ deficiency. (31)

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Proper nutrition is essential during pregnancy for the healthy development of the fetus. Numerous vitamins and minerals are a vital part of proper nutrition. If you are pregnant, think you might be pregnant, trying to get pregnant, or breast-feeding an infant, talk to your healthcare professional about supplementing your diet with appropriate vitamins and minerals.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Vitamins and minerals are an essential part of proper growth and development. Talk to your healthcare professional about the appropriate use of vitamins and minerals in children. Do not use any vitamin or mineral in children under 2 years of age unless first discussed with your healthcare professional.

References

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2. View Abstract: Gutierrez Revilla JI, Perez Hernandez F, Tamparillas Salvador M, Calvo Martin MT. Influence of biochemical and genetic factors on homocysteine concentrations. An Pediatr (Barc). Mar2004;60(3):215-21.
3. View Abstract: Steegers-Theunissen RP. Folate Metabolism and Neural Tube Defects: A Review. Eur J Obstet Gynecol Reprod Biol. Jul1995;61(1):39-48.
4. View Abstract: Evans MI, Llurba E, Landsberger EJ, OBrien JE, Harrison HH. Impact of folic acid fortification in the United States: markedly diminished high maternal serum alpha-fetoprotein values. Obstet Gynecol. Mar2004;103(3):474-9.
5. View Abstract: Norsworthy B, Skeaff CM, Adank C, Green TJ. Effects of once-a-week or daily folic acid supplementation on red blood cell folate concentrations in women. Eur J Clin Nutr. Mar2004;58(3):548-54.
6. Truswell AS. ABC of Nutrition. Nutrition for Pregnancy. Br Med J. (Clin Res Ed) Jul1985;291(6490):263-66.
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8. View Abstract: Larsson SC, et al. Dietary Folate Intake and Incidence of Ovarian Cancer: The Swedish Mammography Cohort. J Natl Cancer Instit. Mar2004;96(5):396-402.
9. View Abstract: Buckley DI, et al. Dietary Micronutrients and Cervical Dysplasia in Southwestern American Indian Women. Nutr Cancer. 1992;17(2):179-85.
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11. View Abstract: Godfrey PS, et al. Enhancement of Recovery from Psychiatric Illness by Methylfolate. Lancet. Aug1990;336(8712):392-95.
12. View Abstract: Lindenbaum J, et al. Nutritional Anemia in Alcoholism. Am J Clin Nutr. Dec1980;33(12):2727-35.
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14. View Abstract: Wang HX, Wahlin A, Basun H, Fastbom J, Winblad B, Fratiglioni L. Vitamin B(12) and folate in relation to the development of Alzheimer’s disease. Neurology. May2001;56(9):1188-94.
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16. View Abstract: Woo KS, Chook P, Lolin YI, Sanderson JE, Metreweli C, Celermajer DS. Folic acid improves arterial endothelial function in adults with hyperhomocystinemia. J Am Coll Cardiol. Dec1999;34(7):2002-6.
17. View Abstract: Brouwer IA, van Dusseldorp M, Thomas CM, Duran M, Hautvast JG, Eskes TK, et al. Low-dose folic acid supplementation decreases plasma homocysteine concentrations: a randomized trial. Am J Clin Nutr. Jan1999;69(1):99-104.
18. View Abstract: Landgren F, Israelsson B, Lindgren A, Hultberg B, Andersson A, Brattstrom L. Plasma homocysteine in acute myocardial infarction: homocysteine-lowering effect of folic acid. J Intern Med. Apr1995;237(4):381-8.
19. View Abstract: Woodside JV, Yarnell JW, McMaster D, Young IS, Harmon DL, McCrum EE, et al. Effect of B-group vitamins and antioxidant vitamins on hyperhomocysteinemia: a double-blind, randomized, factorial-design, controlled trial. Am J Clin Nutr. May1998;67(5):858-66.
20. View Abstract: Dierkes J, Westphal S, Kunstmann S, Banditt P, Lossner A, Luley C. Vitamin supplementation can markedly reduce the homocysteine elevation induced by fenofibrate. Atherosclerosis. Sep2001;158(1):161-4.
21. View Abstract: Swain RA, et al. The Role of Folic Acid in Deficiency States and Prevention of Disease. J Fam Pract. Feb1997;44(2):138-44.
22. View Abstract: Tavani A, et al. Folate and vitamin B6 intake and risk of acute myocardial infarction in Italy. EJCN. Sept 2004;58(9):1266-1272.
23. View Abstract: Nakhoul F, Abassi Z, Plawner M, et al. Comparative study of response to treatment with supraphysiologic doses of B-vitamins in hyperhomocysteinemic hemodialysis patients. Isr Med Assoc J. Apr2004;6(4):213-7.
24. View Abstract: Lentz SR, Piegors DJ, Malinow MR, Heistad DD. Supplementation of atherogenic diet with B vitamins does not prevent atherosclerosis or vascular dysfunction in monkeys. Circulation. Feb2001;103(7):1006-11.
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26. View Abstract: Schnyder G, Roffi M, Flammer Y, Pin R, Hess OM. Effect of homocysteine-lowering therapy with folic Acid, vitamin B12, and vitamin b6 on clinical outcome after percutaneous coronary intervention: the swiss heart study: a randomized controlled trial. JAMA. Aug2002;288(8):973-9.
27. View Abstract: Brattstrom LE, et al. Folic Acid – An Innocuous Means to Reduce plasma Homocysteine. Scand J Clin Lab Invest. May1988;48(3):215-21.
28. View Abstract: Auer J, et al. Homocysteine and cardiovascular risk. Wien Med Wochenschr. 2001;151(1-2):25-8.
29. View Abstract: Stanford JL, et al. Oral folate reduces plasma homocyst(e)ine levels in hemodialysis patients with cardiovascular disease. Cardiovasc Surg. Dec2000;8(7):567-71.
30. View Abstract: Brattstrom LE, et al. Folic Acid Responsive Postmenopausal Homocysteinemia. Metabolism. Nov1985;34(11):1073-77.
31. View Abstract: Stabler SP, et al. Vitamin B-12 deficiency in the elderly: current dilemmas. American Journal of Clinical Nutrition. 1997;Vol 66:741-749.