Résumé
Folic acid antagonists, which include such common drugs as trimethoprim, triamterene, carbamazepine, phenytoin, phenobarbital and primidone, may increase the risk not only of neural-tube defects but also of cardiovascular defect, oral clefts, and urinary tract defects. Folate supplementation before conception and during the first trimester reduces the risk of having infants with neural-tube defects and has the potential to reduce the risk of having infants with other congenital malformations and Down’s syndrome. Long-term use of multivitamins containing folic acid may reduce risks for hypertension, colon cancer, and breast cancer. The fortification of enriched grain products with folic acid also reduces the number of middle-aged and older adults with hyperhomocyteinemia, which is known to be a risk factor for deep-vein thrombosis, myocardial infarction, dementia and Alzheimer’s disease, congestive heart failure, and osteoporotic fracture. Therefore, folate supplementation has the potential to reduce the risk of a wide variety of conditions and diseases. For example, treatment with folate and mecobalamin (B12) reduced risk of hip fracture successfully in elderly patients with hemiplegia following stroke in a Japanese population. However, compared with specifically supplemented/fortified foods, consumption of naturally-occurring levels of folate in non-supplemented/fortified foods has been shown to be relatively ineffective at increasing folate status. Therefore, advice to consume folate-rich foods as a means of optimizing folate status may be misleading. Rather, increased folate intake with supplements is highly recommended.<br>