It is important that women of reproductive age make sure that they are getting enough folate when planning to have a baby, and during pregnancy. The type of folate/folic acid, and the correct usage in terms of timing and doses required is also important.

  Folate is essential for cell division, the development of the spinal cord and the growth of the baby during pregnancy. There is also evidence to support that its consumption after birth benefits as it improves the composition of breast milk and helping to support further infant growth and development. Maternal folate deficiency is associated with fetal congenital malformation. Neural tube defects (NTDs) mainly anencephaly and spina bifida are the most common. In mother, folate deficiency can limit the production of red blood cells leading to megaloblastic anaemia, which is characterised by large immature red blood cells in the peripheral smear.

What is the difference between folate and folic acid?

Folate and folic acid are both forms of the water soluble vitamin B. Folate is the naturally occurring form of the vitamin found in a number of foods, especially vegetables, while folic acid is the synthetic form of the vitamin, and it is used for the fortification of foods (e.g. pasta, cereals, and bread )and the manufacture of supplements.

Food sources of folate

 As shown in figure 1, folate is found in a range of foods including leafy vegetables, pulses, and fruits. When consuming folate it is important to consider some factors such as cooking methods, and  bioavailability.

 Cooking methods can lead to nutrient losses for instance, 100g raw lentils contain 110μg folate, compared with 30μg in a similar proportion of food after cooking. Considering that folate is a soluble vitamin, thus dissolves in water, it is preferable to steam the vegetables rather than boil them.

Figure 1:Natural food sources of folate 

The term bioavailability is used to describe the rate to which a nutrient is more actively absorbed and becomes available in the body. In terms of folate, its bioavailability tend to be low with only about 10 per cent being absorbed by the body, particularly by the time food has been stored, prepared, and cooked. In contrast, the bioavailability of folic acid is much higher with about 90 per cent ingested and being absorbed by the body. Because of its high bioavailability, in 2007, the Food Standards Agency in the UK recommended that folic acid should be added compulsorily to either bread or flour.

Dietary recommendations

It is advised that in addition to dietary sources 0.4mg/day folic acid should be taken from supplement sources. While this is a general recommendation, the ranges of folic acid supplementation vary across Europe from 0.2mg-0.6mg per day, thus is it important to advise your doctor. For all women, folic acid should be taken one month before and at least 12 weeks after conception. In some instances, it may take up to three months to achieve an optimal red blood cell folate level, depending of the folate status in the body when conception occurs and the dose of folic acid taken.

Evidence supports that some women should have higher folate/folic acid requirements than of those of the general population. Women who have had a previous pregnancy affected by a neural-tube defect, women with diabetes, and women with a Body Mass Index of 25kg/m² or more, should take 5mg folic acid daily starting at least one month before conception.

Can folate be harmful if taken on excess?

Women cannot get too much folic acid from foods containing naturally folate. However, when taking folic acid tablets, it is important to be careful on the frequency and the dose of folic acid. Women should not consume more than the recommended amount of folic acid, unless recommended by their health professional. Taking large amounts of folic acid might hide a vitamin B₁₂ deficiency. Although increased folic acid consumption can correct anaemia associated with vitamin B₁₂ deficiency, it cannot correct the changes in the nervous system that result from B₁₂  deficiency which can lead to brain and nerve damage.

In summary,

It is important that women who are planning to become pregnant aim to eat a folate-rich diet, while topping this up with appropriate supplement sources. Supplements should be taken on a daily basis for at least one month before pregnancy and the first 12 weeks once pregnant. Finally, it is important to remember that not all women have the same folate requirements, with women having previous pregnancies with neural-tube defects, obese or diabetes needing higher levels.

References

Betti, C., Fekete, K., Dullemeijer, C., Trovato, M., Souverien, O.W, Cavelaars, A., Dhonukshe-Rutten, R., Massari, T., and Cetin, I. 2012. Folate Intake and Markers of Folate Status in Women of Reproductive Age, Pregnant and Lactating Women. Journal of Nutrition and Metabolism.

Hoyo, C., Murtha, A.P., Schildjraut, J.M., Forman, M.R., Calingaert, B., Demark-Wahnefried, W., Kurtzberg, J., Jirtle, R.L. and Murphy, S.K. 2011. Folic acid supplementation before and during pregnancy in the Newborn Epigenetics Study (NEST). Journal of Public Health. Vol. 11, np. 46

Nulty H.M. and Scott,l.M.,2008. Intake and status of folate and related B-vitamins: considerations and challenges in achieving optimal status. British Journal of Nutrition, vol. 99, no. 3, pp. S48–S54

Talaulikar, V. and Arulkumaran, S., 2011. Folic acid in pregnancy. Available from : http://ac.els-cdn.com/S1751721411000261/1-s2.0-S1751721411000261-main.pdf?_tid=a1456c2c-f6db-11e3-a2a7-00000aab0f01&acdnat=1403091071_014e55777c561cdefc6298e184262385

Food Standards Agency. Board Recommends mandatory fortification. May 2007. Available from <http://webarchive.nationalarchives.gov.uk/20120206100416/http://food.gov.uk/news/newsarchive/2007/may/folatefort>

Daly LE, Kirke PN, Molloy A, Weir DG, Scott JM. Folate levels and neural tube defects. Implications for prevention. JAMA 1995; 274: 1698e702