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Folic acid: a vital nutrient throughout life

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Brenda Griffiths, MA, RGN, RHV.

Public Health Practitioner, Bolton Primary Care Trust


Benefits for childbearing and lactating women
What is folic acid and do I really need it?

Folic acid is the synthetic or supplement form of the nutrient folate, a B vitamin that helps build healthy cells. Folate is found in foods such as green, leafy vegetables, nuts, citrus fruits, beans, meats and orange juice. It is added to fortified breakfast cereals, fortified bread and can be taken as a supplement.

A vital nutrient throughout life, folic acid is particularly important during pregnancy and lactation, when the body's requirement doubles (Mason, 2003).

Research has shown that if taken in the correct dose before conception and during the first 12 weeks of pregnancy, folic acid can greatly reduce the risk of neural tube defects that lead to spina bifida and anencephaly in the unborn baby (Medical Research Council Vitamin Study Research Group, 1991).

The Department of Health recommendation is that all women of childbearing age should take a 400mcg daily supplement (DH, 2000). Women who have already had a baby with a neural tube defect should take a prescription dose of 4000mcg folic acid daily. A healthy diet is also recommended; one that includes foods rich in folate.

The value of supplements
For how long should I take folic acid?

According to Folic Acid Action (FAA), 40% of the UK's pregnant women are too late in taking the essential nutrient folic acid during pregnancy to reduce the risk of neural tube defects.

The critical time for taking folic acid is three months before conception and during the first 12 weeks when the neural tube is developing into the brain and spinal cord.

Because approximately 50% of pregnancies in the UK are thought to be unplanned, women of child-bearing age would benefit from increasing their intake by taking a supplement. The FAA is calling for the recommended daily 400mcg folic acid supplementation to be offered to all women who are ovulating and sexually active.

All those considering folic acid supplementation should consult a health professional when taking prescription, over-the-counter or complementary medicines or other nutritional supplements.

Benefits for older men and women
What other potential benefits does folic acid have?

New research from America suggests that folic acid supplementation may have a role in reducing the risk of high blood pressure (Forman et al., 2005). There are also data suggesting that folic acid reduces raised levels of homocysteine (a naturally occurring amino acid that, when present, can cause damage to blood vessels (Scientific Advisory Committee on Nutrition, 2001). In so doing, it helps prevent the build up of atherosclerosis, that can cause heart disease and stroke. High homocysteine levels are also thought to affect brain function, digestive processes and bone strength.

For men and women above child-bearing age, folic acid supplementation may be beneficial at all stages of life to protect against heart disease, high blood pressure and promote a healthy digestive tract.

US researchers claim that taking a daily supplement of folic acid could protect women against the detrimental effects of a high alcohol intake (Department of Nutrition, Harvard School of Public Health, 2003).

Researchers at The Brigham and Women's Hospital in Boston, USA, studied more than 150,000 women in two age groups to see if there was a link between the risk of high blood pressure and their folic acid intake.

In the group of women 26 to 46 years consuming more than 800mcg of folate daily they found an apparent protective effect of increased folic acid against high blood pressure (Forman et al, 2005). Older women in a 43- to 70-year-old group who ate the most folate also reduced the risk of high blood pressure, but by a more modest 13% compared to the low-folate group.

Dietary sources
Can I get all the folic acid I need from a healthy diet?

On average, it is possible to gain around 150 to 200mcg daily by eating a diet rich in fruit and vegetables (Sanderson, 2003; Mason, 2003).

Folic acid is easily depleted by factors such as pollution, excessive alcohol, smoking and processed foods. The naturally occurring form of folic acid - folate - is less easily absorbed by the body than a supplement (DH, 2000).

In reality, achieving the 400mcg recommended daily allowance through diet alone, would be a challenge. This is why the government recommends that a supplement be taken for women of childbearing age planning a pregnancy.

- Folic Acid Action is a campaign involving a multiprofessional group of health professionals who believe that more should be done to raise awareness about when to start folic acid supplementation.

Author contact details
Brenda Griffiths, e-mail:

Further reading
Department of Health (2004)Thinking of Having a Baby? Folic acid - what all women should know. London: DH.

Department of Health (2000)Folic Acid and Prevention of Disease: Report of the Committee on Medical Aspects of Food Policy (COMA). Report on health and social subjects. London: Stationery Office.

Department of Nutrition, Harvard School of Public Health (2003)Joint association of alcohol and folate intake with risk of major chronic disease in women. American Journal of Epidemiology 158: 8, 760-761.

Folic Acid Action (2004)Improving Awareness and Uptake of Folic Acid. London: Folic Acid Action Group. Available on:

Forman, J.P., Rimm, E.B., Meir, J.S. et al. (2005)Folate intake and the risk of incident hypertension among US women. Journal of the American Medical Association 293: 320-329.

Mason, P. (2003)Nutrition in pregnancy. Pharmaceutical Journal 270: 369-370.

Medical Research Council Vitamin Study Research Group (1991)Prevention of neural tube defects. Results of the MRC vitamin study. Lancet 338: 131-137.

Sanderson, P., McNulty, H., Mastroicovo, P. et al. (2003)Folate bioavailability; UK Food Standards Agency Workshop Report. British Journal of Nutrition 90: 473-479.

Scientific Advisory Committee on Nutrition (2001)Folates and disease prevention. An update. London: Food Standards Agency.

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