Methionine in the multifactorial etiology of neural tube defect affected pregnancies

PURPOSE: Research in the last 40 years has provided evidence of the role of dietary nutrients in the development of NTDs. Failure of the neural tube to close is one of the most frequent and severe fetal developmental defects. The etiology of NTDs is complex encompassing genetic, dietary, and environmental factors. With regard to diet, it appears that in humans, a combination of low levels of methionine, folate, and Vitamin B(12) may lead to the occurrence of NTDs. The purpose of this study was to explore the relationship between maternal dietary intake of methionine and the risk of having a NTD affected pregnancy.METHODS: It was hypothesized that women with high maternal dietary methionine intake were at a decreased risk for NTDs. Combinations of methionine and folate without supplements, methionine and folate with supplements, and methionine and Vitamin B(12) and NTD risk were also examined. Data from a case-control study of 170 NTD-affected pregnancies and 269 controls were provided by a CDC sponsored NTD Surveillance, Prevention, and Research Project.RESULTS: There was an approximately 30-55% reduction in NTD risk among women whose average daily dietary intake of methionine was greater than the lowest quartile of intake (>1580 mg/day). The odds ratios (95% CI) associated with the 3 quartiles of methionine intake greater than 1580 mg/day after adjusting for Kcal, race, and BMI were 0.72 (0.4030-1.288), 0.68 (0.3390-1.347), and 0.45 (0.1830-1.088).CONCLUSIONS: These findings indicate a reduction in the risk of having a NTD affected pregnancy is associated with maternal periconceptional dietary intake of methionine.