Public health significance of supplementation or fortification of grain products with folic acid

Authors: Selhub, Jacob; Rosenberg, Irwin

Submitted to: Food and Nutrition Bulletin
Publication Type: Proceedings
Publication Acceptance Date: 10/18/2005
Publication Date: 6/1/2008
Citation: Selhub, J., Rosenberg, I. 2008. Public health significance of supplementation or fortification of grain products with folic acid. Food and Nutrition Bulletin. 29(2)(Suppl):S173-S176.

Interpretive Summary: In 1998 the US has begun fortifying flour and grain products with folic acid. The program was intended to reduce the incidents of spina bifida, birth defects which were shown in early studies to be reduced when the women takes folic acid before pregnancy or/and during the first 6 weeks of pregnancy. However because this fortification is for the entire US population, this article discusses the need to do research to determine risks and benefits of this program. One of the risks is excessive intake of folic acid by elderly who often have a deficiency in vitamin B12. There is a chance of increased dementia and anemia and other illnesses in this population. Folic acid in supplement and fortified foods is a synthetic form of the vitamin which requires specific handling by the body in order to render it active. Without this folic acid could potentially be harmful.

Technical Abstract: The need for supplemental folate can be traced to the initial phase of the discovery of this vitamin as a micronutrient for the prevention of pregnancy related anemia. In the post discovery era, folic acid was used primarily to prevent deficiency as manifested by low blood folate levels and megaloblastic anemia. The need for population based supplementation evolved primarily with the discovery that preconceptional intake of folic acid could prevent NTD related births. What was important in this discovery was that unlike megaloblastic anemia where blood folate levels are clearly much lower than normal, folate status in women with NTD-affected births is mostly within the normal range, sometime in the low end of the normal range. Other examples of what appears to be increased benefit from supplemental folate in face of what is considered to be normal folate status, created the concept that certain segments of the population may require more folate than the local diet is capable of supplying because of altered folate-dependent metabolic activity. Folic acid is the parent compound of the folate vitamer family. It is not found in nature and is prepared by chemical synthesis. Because of its commercial availability in large quantities and high stability, folic acid is the form which is used for supplements and fortified foods. Fortification in the USA and Canada with folic acid, appears to have produced positive results. However certain recent data on excessive intake of folic acid appears to have some adverse effects and hence there is a need to continue monitoring for both benefits and risks when a fortification strategy is implemented.