Why Countries Around The World Differ In Their Recommendations About Folic Acid Supplementation Before and During Pregnancy
Far too many advisers of nutrition and public health think folic acid is naturally found in foods. The body does not metabolize folic acid in the same way it does folate which is in foods such as lentils, beans, spinach and other greens. Five countries recommend folate and folic acid consumption around conception above and beyond World Health Organisation (WHO) guidelines, while five others dismiss supplementation as unnecessary, report finds.
Researchers from the Institute of Food Research and Newcastle University have confirmed that the body processes synthetically-produced folic acid differently to the natural counterpart found in vegetables. This leads to unmetabolized folic acid circulating in the bloodstream which is eventually metabolized by the liver, but the process is slow, inefficient and possibly toxic.
Portugese researchers looked at the recommendations of 36 different countries and found that the majority (69.4%) followed World Health Organisation (WHO) recommendations of a healthy diet plus folic acid supplementation of 400 micrograms per day from preconception (4-12 weeks) until the end of the first trimester of pregnancy (8-12 weeks).
The report, published in Public Health Nutrition, included: Australia, Austria, Belgium - Flanders, Brazil, Bulgaria, Canada, China, Denmark, Estonia, Finland, France, Germany, Hong Kong, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Russia, Singapore, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, the UK and the US.
Folate is a very important B vitamin, and low levels may be involved in certain carcinogenic processes. If more people could supplement their folate intake from fruits and legumes, rather than from a folic acid supplement it could condition the population to regulate from a natural source as synthetic fortification is far inferior to natural sources of folate. These foods have other cancer-fighting properties and can help protect against other chronic diseases.
"Interestingly, five countries (13.9 % - Finland, France, Sweden, Singapore and Taiwan) considered that a healthy diet containing adequate amounts of folate may be enough, with no need for supplementation," wrote the researchers from the Institute of Public Health of the University of Porto, University of Porto Medical School and the Universidade Catolica Portuguesa/Porto.
Mandatory fortification was seen in Australia, Brazil, Canada, South Africa and the US - where supplementation was also recommended.
A study published in PloS One, investigated whether folic acid supplementation is linked to an increased risk for the progression of established mammary tumours using a rat model after previous research suggested a link between high intakes of the B vitamin and breast cancer risk.
As the UK considers whether to follow the example of the USA, Canada and Australia and 70+ other nations in introducing mandatory folic acid fortification programmes, the researchers are urging the government to either consider using a different folate form, or further investigate the implications of excess folic acid.
For just over 40% of the countries, the dosage for women with a high risk of neural tube defects was up to 4-5 mg per day.
All of the countries issued advice on healthy diet and/or folate-rich food.
Advice to expect
The timings for supplementation also differed across countries. About 33% said at least four weeks before conception, as stated in the D-A-CH (Germany, Austria and Switzerland) recommendations.
About 27% of them stated supplementation should begin when planning pregnancy or when there was a chance of becoming pregnant/capable of becoming pregnant, in line with the US's Institute of Medicine (IOM).
Nearly 14% mentioned at least 12 weeks before pregnancy. Two countries referred to 4-8 weeks or 8-12 weeks before conception, two advocated when contraception was stopped and one country recommended at least eight weeks before stopping contraception.
Most said supplementation should be maintained until the end of the first trimester (12 weeks) or almost (ten or 8-12 weeks), but Canada, China and USA recommended supplementation until the end of pregnancy.
Some countries - Singapore and South Africa - advised women to ask a health care professional.
Fortify with Folates
"We only carry out studies and don't make policy decisions, but we'd hope that future decisions about fortification with folic acid take into account our central finding -- that we don't metabolise folic acid in the same way as natural folates," stated research leader Paul Finglas.
"Where fortification does happen, we'd suggest the forms of methyltetrahydrofolic acid (the natural form of the vitamin in food and main circulating form in the body) could be considered as an alternate fortificant to folic acid now that more stable synthetic forms have been made available commercially."
Researchers have reported that 86% of folic acid in the hepatic portal vein (which carries blood from the gut to the liver) remains unmetabolized, while almost all of the natural folate was converted correctly.