Micronutrients and women of reproductive potential: Required dietary intake and consequences of dietary deficiency or excess. Part I-Folate, Vitamin B12, Vitamin B6

College of Medicine, Florida International University, Miami, FL 33199, USA.
The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians (Impact Factor: 1.37). 04/2010; 23(12):1323-43. DOI: 10.3109/14767051003678234
Source: PubMed


This two-part review highlights micronutrients for which either public health policy has been established or for which new evidence provides guidance as to recommended intakes during pregnancy. One pivotal micronutrient is folate, the generic name for different forms of a water-soluble vitamin essential for the synthesis of thymidylate and purines and, hence, DNA. For non-pregnant adult women the recommended intake is 400 μg/day dietary folate equivalent. For women capable of becoming pregnant an additional 400 μg/day of synthetic folic acid from supplements or fortified foods is recommended to reduce the risk of neural tube defects (NTD). The average amount of folic acid received through food fortification (grains) in the US is only 128 μg/day, emphasising the need for the supplemental vitamin for women of reproductive age. Vitamin B12 (cobalamin) is a cofactor required for enzyme reactions, including generation of methionine and tetrahydrofolate. B12 is found almost exclusively in foods of animal origin (meats, dairy products); therefore, vegetarians are at greatest risk for dietary vitamin B12 deficiency and should be supplemented. Vitamin B6 is required for many reactions, primarily in amino acid metabolism. Meat, fish and poultry are good dietary sources. Supplementation beyond routine prenatal vitamins is not recommended.

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    • "Folate, or vitamin B9, is most abundantly found in dark green leafy vegetables, but also in orange juice, legumes (e.g., black beans and kidney beans), nuts, asparagus, and strawberries. With the exception of liver, meat is not a good source of folate [17]. Folic acid is the synthetic form of folate and is usually more bioavailable than natural food folate. "
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    ABSTRACT: Nutritional deficiencies are preventable etiological and epigenetic factors causing congenital abnormalities, first cause of infant mortality. Folate deficiency has a well-established teratogenic effect, leading to an increasing risk of neural tube defects. This paper highlights the most recent medical literature about folate deficiency, be it maternal or paternal. It then focuses on associated deficiencies as nutritional deficiencies are multiple and interrelated. Observational and interventional studies have all been consistent with a 50-70% protective effect of adequate women consumption of folates on neural tube defects. Since strategies to modify women's dietary habits and vitamin use have achieved little progress, scientific as well as political effort is mandatory in order to implement global preventive public health strategies aimed at improving the alimentation of women in reproductive age, especially folic acid supplementation. Even with the recent breakthrough of fetal surgery for myelomeningocele, the emphasis should still be on prevention as the best practice rather than treatment of neural tube defects.
    Full-text · Article · Aug 2012 · Journal of pregnancy
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    • "NTDs may also be the result of vitamin B 12 deficiency, independent of the mother's folate status (Simpson et al., 2010). Studies are very limited with respect to the vitamin B 12 status and dietary intakes of the Nigerian population. "
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    ABSTRACT: Lindsay K.L., Gibney E.R. & McAuliffe F.M. (2012) Maternal nutrition among women from Sub-Saharan Africa, with a focus on Nigeria, and potential implications for pregnancy outcomes among immigrant populations in developed countries. J Hum Nutr Diet. Pregnant women in countries of Sub-Saharan Africa (SSA) are at risk of poor nutritional status and adverse outcomes as a result of poverty, food insecurity, sub-optimal healthcare facilities, frequent infections and frequent pregnancies. Studies from Nigeria, for example, have revealed a high prevalence of both under- and over-nutrition, as well as nutrient deficiencies, including iron, folate, vitamin D and vitamin A. Subsequently, obstetric complications, including hypertension, anaemia, neural tube defects, night-blindness, low birth weight and maternal and perinatal mortality, are common. Migration patterns from SSA to the Western world are on the rise in recent years, with Nigerians now representing the most prevalent immigrant African population in many developed countries. However, the effect of immigration, if any, on the nutritional status and pregnancy outcomes of these women in their host countries has not yet been studied. Consequently, it is unknown to what extent the nutritional deficiencies and pregnancy complications occurring in Nigeria, and other countries of SSA, present in these women post-emigration. This may result in missed opportunities for appropriate antenatal care of a potential high-risk group in pregnancy. The present review discusses the literature regarding nutrition in pregnancy among SSA women, using Nigeria as an example, the common nutrition-related complications that arise and the subsequent obstetric outcomes. The concept of dietary acculturation among immigrant groups is also discussed and deficiencies in the literature regarding studies on the diets of pregnant immigrant women are highlighted.
    Full-text · Article · May 2012 · Journal of Human Nutrition and Dietetics
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    • "If an anencephaly is recognized only late in gestation or even only at birth, the psychologic shock for the parents is usually prominent, and in their desperation to have at least some positive aspect in an otherwise hopeless situation parents have even requested in these rare situations to have organs transplanted from anencephalic donors (Holzgreve et al. 1987). NTDs have multiple etiologies and the role of folate, other vitamins and various micronutrients as factors in their etiology has been investigated from different angles for a long time now (Holzgreve et al., 1991, Simpson et al., 2010, 2011) A number of observational and interventional studies have demonstrated that folic acid (FA) supplementation before and in early pregnancy reduces the risk of having a NTD-affected offspring (Laurence et al., 1981; Milunsky et al. 1989; Smithells et al., 1980; Vergel et al., 1990). "

    Full-text · Chapter · Mar 2012
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