			Home About us Contact

Folic Acid Supplementation (folic + acid_supplementation)

Distribution by Scientific Domains

Medical Sciences	56%
Life Sciences	43%

Selected Abstracts

Hyperhomocysteinemia in Children Treated with Antiepileptic Drugs Is Normalized by Folic Acid Supplementation

EPILEPSIA, Issue 10 2005
Martina Huemer
Summary:,Purpose: To assess the prevalence of hyperhomocysteinemia in pediatric patients treated with antiepileptic drugs (AEDs) and to evaluate the effect of folic acid supplementation on plasma total homocysteine (tHcy) concentrations in hyperhomocysteinemic patients. Methods: 123 patients from three regional hospitals participated in the study. Patients with hyperhomocysteinemia were included in a 3-month double-blind randomized trial testing oral folic acid supplementation (1 mg/day) versus placebo. Results: Hyperhomocysteinemia (tHcy >10.4 ,mol/L) was present in 19 of 123 patients. Patients with hyperhomocysteinemia were older (13.7 ± 4 vs. 11.0 ± 3.9 years) and had significantly lower folate and cobalamin concentrations. Multidrug (two or more) AED treatment and duration of therapy correlated significantly with elevated total homocysteine (tHcy) and low folate. In contrast, polymorphisms in the methylene tetrahydrofolate reductase gene (MTHFR 677 C,T, 1298 A,C, 1793 G,A) had no significant impact on tHcy. Nine of 19 patients with hyperhomocysteinemia were randomized to placebo, whereas the remaining 10 patients received folic acid supplementation. Folic acid supplementation resulted in a significant increase of folate and decrease of tHcy, whereas both parameters remained unchanged in the placebo group. Conclusions: Hyperhomocysteinemia is present in 15.5% of children receiving long-term AED treatment. Multidrug treatment and long duration of therapy enhance the risk for hyperhomocysteinemia. Folic acid supplementation significantly reduces tHcy. We recommend assessment of serum folate and plasma tHcy in children receiving AEDs. [source]

Prevalence and risk factors for anaemia in pregnant women: a population-based prospective cohort study in China

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 4 2009
Qiaoyi Zhang
Summary Maternal anaemia is a common pregnancy complication in developing countries; however, its epidemiology remains largely unexplored in China. This study was designed to explore the epidemiology and risk factors of anaemia during pregnancy. A prospective cohort study was conducted, using data from a population-based pregnancy-monitoring system in 13 counties in East China (1993,96). Women who delivered singleton infants at 20,44 weeks with at least one haemoglobin assessment during pregnancy were included (n = 164 667). The prevalence of anaemia (haemoglobin < 10 g/dL) during pregnancy as well as in each trimester was estimated. Multivariable log-binomial regression models were used to evaluate risk factors. The overall prevalence of anaemia in pregnancy was 32.6%, with substantial variations across trimesters (11.2%, 20.1% and 26.2% in the 1st, 2nd and 3rd trimesters respectively). Risk factors for anaemia included older maternal age, education below junior high school (prevalence rate ratio [RR] 1.10, 95% confidence interval [CI] 1.08, 1.12), farming occupation (1.05, 95% CI 1.03, 1.06), and mild pregnancy-induced hypertension (PIH) (RR 1.09, 95% CI 1.05, 1.13) and severe PIH (RR 1.13, 95% CI 1.06, 1.19). Peri-conception folic acid use was associated with a reduced risk for anaemia in the 1st trimester (RR 0.75, 95% CI 0.72, 0.78). Initiating prenatal care after the 1st trimester was associated with increased risk of anaemia in the 2nd and 3rd trimesters. Our study found anaemia during pregnancy is highly prevalent in this indigenous Chinese population. The risk increases with the severity of hypertensive disorders. Folic acid supplementation during the peri-conception period is associated with reduced risk of 1st trimester anaemia. [source]

Peri-conceptual folic acid supplementation in type 1 diabetes

PRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 4 2001
C.J. Wills Specialist Registrar in Diabetes, Endocrinology
Abstract Aim To document peri-conceptual folic acid supplementation in women with type 1 diabetes mellitus (DM) attending the diabetic ante-natal clinic of a university teaching hospital. Methods Women with pre-existing type 1 DM who booked at the diabetes antenatal clinic at University Hospital, Nottingham over 3 years (1996,98) took part in a telephone survey about folic acid supplements. Results Data was available on 50 women, 65 pregnancies. Folic acid supplements were used before 50.7% (33) pregnancies, all planned, and started on confirmation of pregnancy in 34% (22), at a mean gestation of 5.8 weeks. No folic acid was used before or during 10 (15.4%) pregnancies. 75.4% (49) pregnancies were planned. 24 planned pregnancies were in women who had never had pre-pregnancy counselling. 70.8%(17) of these were in multiparous women, and folic acid was taken before 41.1% (seven) of such pregnancies. Lack of awareness was the predominant reason for failure to take folic acid supplements in all groups. Conclusions Folic acid was taken before conception in only half of the pregnancies in the survey, due to lack of awareness of its importance. Three-quarters of pregnancies were planned but a disappointing number of women had pre-pregnancy counselling, probably due to poor advertising and the assumption that women who had been pregnant before did not need such a session. Women with DM should be informed about folic acid and offered pre-pregnancy counselling. It should not be assumed that women who have had a pregnancy know about folic acid. Copyright © 2001 John Wiley & Sons, Ltd. Key Points Folic acid supplementation prior to conception and in the first trimester helps to prevent neural tube defects. Almost half of the women in this survey failed to take folic acid prior to conception. Women who did not take folic acid were unaware of its importance. We need to ensure that women with diabetes understand the importance of folic acid. [source]

Plasma vitamin values and antiepileptic therapy: Case reports of pregnancy outcomes affected by a neural tube defect

BIRTH DEFECTS RESEARCH, Issue 1 2007
Mirande Candito
Abstract BACKGROUND: Folic acid supplementation reduces the occurrence of neural tube defects (NTDs); however, it is not clear whether it protects against teratogenic effects of antiepileptic drugs. METHODS: We report the cases of four pregnant women receiving valproic acid therapy, who all had NTD-affected offspring, despite periconceptional 5 mg/day of folic acid supplementation (cases), and investigated homocysteine metabolism, linked with folate metabolism. Their plasma homocysteine, folates, and vitamin B6 and B12 results were compared with values of two other women, who were also receiving valproic acid and folic acid complement, but who had normal pregnancies (valproic acid controls), and values of 40 pregnant women who had normal pregnancies and were not receiving any therapy (controls without therapy). Because of the possible existence of a genetic susceptibility, polymorphisms in homocysteine metabolism were sought. RESULTS: Two cases showed a decreased phosphopyridoxal level, compared with levels in the controls not receiving therapy. The genotype TT (C677T) is an NTD genetic susceptibility, but it was observed in only one valproic acid control. Various polymorphisms were observed in the cases, but were also common in the controls. Several studies have reported that valproic acid therapy lowers vitamin B6 levels. Our case with the greatest decrease in plasma phosphopyridoxal, who was taking periconceptional folic acid plus pyridoxine therapy, had a normal second pregnancy outcome. CONCLUSIONS: In addition to folates, other vitamins, such as vitamin B6, may have played a role in NTDs in our patients taking an antiepileptic drug. Birth Defects Research (Part A) 2007. © 2006 Wiley-Liss, Inc. [source]

Folic acid supplementation on red kidney bean-induced diarrhoea and enteric bacterial translocation into mesenteric lymph nodes in rats: a pilot study

ACTA PAEDIATRICA, Issue 1 2002
R Shoda
Deaths following childhood diarrhoea, a major health problem in developing countries, are often associated with malnutrition and septicaemic complications. Folic acid has been used in the treatment of acute and chronic diarrhoea in the tropics. Using a rat model, we evaluated the protective effect of large doses of folic acid on diarrhoea, small intestinal bacterial overgrowth and translocation of enteric bacteria into mesenteric lymph nodes induced by a raw red kidney bean-based diet containing lectin (phytohemagglutinin). Long-Evans rats in 2 groups of 5 each (60 g to 70 g in weight, 28 d old) were used. All 10 rats, individually kept in metabolic cages, received a raw red kidney bean-based diet for 10 d, and 5 of them also received a daily folic acid supplement (160 ,g/g feed) both during and for 10 d before the experiment. The faecal weight was measured and a quantitative aerobic bacterial culture of the small intestinal mucosal scrapings and of the mesenteric lymph nodes was made. Folic acid supplementation did not reduce faecal output nor did it prevent loss of body weight associated with lectin-induced diarrhoea. However, the mean total count of enteric bacteria translocated to the mesenteric lymph nodes was significantly reduced in the supplemented rats (1.27 ± 0.61 vs 2.66 ± 0.84, p= 0.028) and a trend towards reduced bacterial count in the small intestinal mucosal scrapings (0.40 ± 0.89 vs 1.42 ± 1.31, p= 0.16) was documented. A significant positive correlation was also seen between the bacterial count in the jejunal mucosal scrapings and in the mesenteric lymph nodes. Conclusion: Although large-dose folic acid supplementation did not prevent diarrhoea and malnutrition induced by a lectin-based diet, it substantially reduced the count of enteric bacteria translocated into the mesenteric lymph nodes and showed a trend towards a reduction in indigenous bacteria adhering to jejunal mucosa. These findings could be of relevance in the prevention of septicaemic complications following many clinical conditions, including diarrhoea with malnutrition in children known to have bacteraemic and septicaemic complications. [source]

Congenital malformations in infants whose mothers reported the use of folic acid in early pregnancy in Sweden.

CONGENITAL ANOMALIES, Issue 4 2007
A prospective population study
ABSTRACT The use of folic acid prior to conception is generally recommended for the prevention of birth defects, notably neural tube defects. In a previous study from Sweden, based on interviews of women in early pregnancy, no such effect was found on the general malformation rate, but data for neural tube defects were scarce. Using data from the Swedish Medical Birth Register for the years 1995,2004, 20 891 women were identified who reported the use of folic acid in early pregnancy, but not of anticonvulsants. These women were compared to all other women who gave birth during the study period. Malformations in the infants born were identified from multiple sources. No reduction in the general malformation rate was seen among infants born to women who reported the use of folic acid (OR = 1.09, 95% CI 1.02,1.17) and no effect of neural tube defect rate was seen (RR = 1.35, 95% CI 0.82,2.22), based on 16 infants with neural tube defect whose mother reported the use of folic acid. No effect was seen on the rates of other malformations except for cardiac defects, where a statistically significant increased risk (notably for severe defects) was found (OR = 1.19, 95% CI 1.05,1.35). The effect of various deficiencies in data collection is discussed, but is unlikely to explain the lack of protective effect noticed. So far, it has not been possible to demonstrate a beneficial effect of folic acid supplementation on malformation risk in Sweden. A more complete ascertainment and detailed timing and dosage of folic acid use in a prospective study is recommended. [source]

Hyperhomocysteinemia in Children Treated with Antiepileptic Drugs Is Normalized by Folic Acid Supplementation

Uremic hyperhomocysteinemia: A randomized trial of folate treatment for the prevention of cardiovascular events

HEMODIALYSIS INTERNATIONAL, Issue 2 2007
Areuza C. A. VIANNA
Abstract Homocysteine is a risk factor for atherosclerosis in the general population, and serum homocysteine levels are almost universally elevated in chronic renal failure patients. When such patients are treated with dialysis, cardiovascular disease accounts for more than 50% of their mortality, which, in some proportion, may be pathophysiologically related to the elevated serum homocysteine levels. From April 2003 to March 2005, we conducted a 2-year, double-blind, randomized, placebo-controlled trial of 186 patients with end-stage kidney disease due to any cause, who were older than 18 years and stable on hemodialysis. Patients were assigned to receive either oral folic acid 10 mg 3 times a week immediately after every dialysis session under nurse supervision or an identical-appearing placebo for the entire study. On admission, plasma total homocysteine (tHcy) levels were above 13.9 ,mol/L in 96.7% of patients (median 25.0 ,mol/L, range 9.3,104.0 ,mol/L). In the placebo group, tHcy levels remained elevated at 6, 12, and 24 months, while oral folate significantly decreased tHcy to a median value of 10.5 (2.8,20.3) ,mol/L, (p<0.01). During the study, 38 patients (folic acid group 17 vs. placebo group 21; p=0.47) died from cardiovascular disease. Kaplan,Meier life table analysis dealing with the incidence of cardiovascular events, both fatal and nonfatal (myocardial infarction, arrhythmias, angina, heart failure, cerebrovascular accident), showed that 2 years of folic acid treatment and the lowering of the homocysteine blood levels had no effect on cardiovascular events (p=0.41; hazard ratio 1.24, 95% CI 0.74,2.10). However, the carotid artery intima-media wall thickness measured in a blinded fashion decreased from 1.94 ± 0.59 mm to 1.67 ± 0.38 mm (p<0.01) after 2 years of folate therapy. In this short-term study of uremic patients, 2 years of folic acid supplementation normalized the tHcy blood levels in 92.3% of patients but did not change the incidence of cardiovascular events compared with the control group. However, ultrasonography of the common carotid arteries performed at entry and 24 months later showed a significant decrease in intima-media thickness with folate supplementation. This suggests that early folate supplementation may benefit patients with chronic renal failure by preventing cardiovascular deterioration. [source]

The effect of oral folic acid upon plasma homocysteine, endothelial function and oxidative stress in patients with type 1 diabetes and microalbuminuria

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 4 2008
F. Wotherspoon
Summary Aims:, The purpose of this study was to investigate the effect of oral folic acid supplementation upon plasma homocysteine (HCY), endothelial function and oxidative stress on patients with type 1 diabetes and microalbuminuria to test the hypothesis that oral folic acid would lower plasma HCY and thereby improve endothelial function and reduce oxidant stress in this high-risk group of patients. Methods:, We measured plasma HCY, forearm blood flow, total antioxidant status and whole blood glutathione at baseline and after 2 months treatment with oral folic acid or placebo in 16 patients with type 1 diabetes and microalbuminuria. Results:, Plasma HCY fell by 25% in the folic acid group but there was no difference in endothelial function or markers of oxidant stress in the treatment group. Conclusions:, Oral folic acid supplementation successfully lowered plasma HCY levels in patients with type 1 diabetes and microalbuminuria, however this was not associated with improvements in endothelial function or markers of oxidant stress. [source]

G1793A polymorphisms in the methyl- enetetrahydrofolate gene: Effect of folic acid on homocysteine levels

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 8 2006
Sandra Soares Melo
Abstract Mutations or polymorphisms in the gene of the enzyme methylenetetrahydrofolate (MTHFR) are associated with hyperhomocysteinemia and possibly with an elevated risk for vascular diseases. A study was conducted on 83 individuals with type 2 diabetes in order to determine the allelic and genotypic frequencies of the G1793A mutation and to assess the effect of folic acid supplementation on plasma homocysteine concentrations. The patients were attended by the Diabetes and Hypertension Program , Balneario Camboriu/SC and received daily supplements containing 1 mg of folic acid for 3 months. DNA was previously extracted from leukocytes and the G1793A mutation was detected by PCR-RFLP. Blood samples were collected during the basal period and after supplementation for the determination of homocysteine by HPLC, and of folic acid and vitamin B12 by RIA. The allele frequency for the G1793A mutation was 3.01% and no homozygous individuals with mutant alleles were detected. Hyperhomocysteinemia was diagnosed in 27.71% of the patients, folic acid deficiency in 15.66%, and vitamin B12 deficiency in 7.23%. Plasma homocysteine concentrations were inversely correlated with folic acid (r = ,0.27, p = 0.01) and vitamin B12 (r = ,0.21; p = 0.05) concentrations. The individuals with a heterozygous genotype for the G1793A mutation showed borderlines or deficient values in folic acid and vitamin B12 concentrations compared to individuals with a normal genotype. Hyperhomocysteinemia and the vitamin deficiencies presented by type 2 diabetic individuals, included with a heterozygous genotype for the G1793A mutation in the MTHFR gene, reached normal values by daily folic acid supplementation. [source]

Factors influencing twins and zygosity

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2005
Gary V. D. Hankins
Summary Zygosity is influenced by many factors. Monozygotic twins occur spontaneously in approximately 1 in 250 births and are felt to increase twofold with ovulation induction techniques. Monozygotic twinning also increases in proportion to the number of blastocysts transferred during in vitro fertilisation. In contrast, dizygotic twinning appears to be influenced by race, genetic factors, maternal age, fertility enhancing drugs, folic acid supplementation, and maternal nutritional status. [source]

A population-based birth defects surveillance system in the People's Republic of China

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2003
Song Li
Summary We describe a unique birth defects surveillance system in the People's Republic of China. The system was instituted in March 1992 as a component of an evaluation of the effectiveness of a public health campaign using periconceptional folic acid supplementation to prevent neural tube defects, and currently surveys birth cohorts of , 150 000 infants per year. Local health care providers collect information in the form of detailed written descriptions and photographs of affected infants. The system allows for detection of birth defects at the local level with later definitive classification and coding; however, information is limited to structural anomalies that are visible on physical examination. This birth defects surveillance system provides an extensive database of infants with major and minor external structural anomalies, including the unique feature of a photographic record for most cases. These data can be used for aetiological studies, descriptive epidemiology and identification of unusual trends. [source]

Genetic factors associated with skin cancer in renal transplant patients

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2-3 2007
Mary Elizabeth Laing
Background: Non-melanoma skin cancer represents a significant cause of morbidity and mortality among renal transplant recipients. Established risk factors that increase susceptibility to skin cancer after transplantation include skin type, sun exposure and level of immunosuppression. Methods: A comprehensive literature review was carried out to discuss relevant genetic polymorphism for the development of skin cancer in organ transplant recipients. These include genetic polymorphisms in glutathione S -transferase, interleukin-10, retinoblastoma and p53 genes. We also discuss genetic polymorphisms in the folate pathway, melanocortin 1 receptor and vitamin D receptor recently discovered in our group. Results: No single factor is causative in cutaneous carcinogenesis in transplant recipients. Interactions of some of the above mechanisms with known environmental factors lead to increased risk. Conclusion: Polymorphisms in methylenetetrahydrofolate reductase are potentially correctable with folic acid supplementation; however, further evaluation is required in adequately powered prospective clinical trials. Avoidance of known oncogenic environmental factors and genetic risk evaluation may improve outcomes in transplant patients. [source]

Peri-conceptual folic acid supplementation in type 1 diabetes

Methotrexate catabolism to 7-hydroxymethotrexate in rheumatoid arthritis alters drug efficacy and retention and is reduced by folic acid supplementation

ARTHRITIS & RHEUMATISM, Issue 8 2009
Joseph E. Baggott
Objective To assess the catabolism of methotrexate (MTX) to 7-hydroxy-MTX (7-OH-MTX) in patients with rheumatoid arthritis as well as the effect of folic acid and folinic acid on this catabolism. Methods Urinary excretion of MTX and its catabolite, 7-OH-MTX, was measured in 2 24-hour urine specimens collected after MTX therapy. Urine samples were collected from patients after the sixth and seventh weekly doses of MTX. MTX and 7-OH-MTX concentrations were determined by high-performance liquid chromatography mass spectrometry. Swelling and pain/tenderness indices were used to measure symptoms before and at 6 and 7 weeks of therapy. Patients received either folic acid or folinic acid supplements (1 mg/day) from week 6 to week 7. Results Folic acid inhibited aldehyde oxidase (AO), the enzyme that produces 7-OH-MTX, but folinic acid did not. Excretion of 7-OH-MTX (determined as a percentage of the dose of MTX or as mg 7-OH-MTX/gm creatinine) was not normally distributed (n = 39). Patients with marked improvement in swelling and pain/tenderness indices had a lower mean 7-OH-MTX excretion level (P < 0.05). Patients who received folic acid supplements had decreased 7-OH-MTX excretion (P = 0.03). Relatively high 7-OH-MTX excretion was correlated with relatively high MTX excretion and with relatively low MTX retention in vivo (P < 0.05) (n = 35). Conclusion Our findings of a non-normal distribution of 7-OH-MTX excretion suggest that there are at least 2 phenotypes for this catabolism. Decreased 7-OH-MTX formation suggests folic acid inhibition of AO and a better clinical response, while increased 7-OH-MTX formation may interfere with MTX polyglutamylation and binding to enzymes and, therefore, may increase MTX excretion and decrease MTX retention and efficacy in vivo. [source]

A Festschrift in Honor of Professor R.W. Smithells

BIRTH DEFECTS RESEARCH, Issue 4 2009
Mary Seller
This issue of Birth Defects Research Part A: Clinical and Molecular Teratology, comprises a Festschrift, a tribute to Professor R. W. (Dick) Smithells (1924-2002). In the 1970s, Dick initiated a study on the prevention of neural tube defects (NTD) by periconceptional multivitamin and folic acid supplementation of ,at risk' women. A significantly positive result was obtained,the first time that the primary prevention of any congenital malformation had ever been achieved. This important discovery stimulated an explosion of similar and related studies, and over the years, an extension of research into many closely allied but disparate fields. The papers in this Festschrift tell some of this story. However, the story itself has, as yet, no ending, because despite Dick's pioneering work and all our accumulated knowledge, the precise cause of NTD, and its mechanism, remains unknown. The authors contributing to this issue dedicate their work to the memory of Dick, and together with many other scientists, doctors and patients worldwide acknowledge and pay homage to his inspiration, industry and foresight. Birth Defects Research (Part A), 2009. © 2009 Wiley-Liss, Inc. [source]

Cardiovascular abnormalities in Folr1 knockout mice and folate rescue,

BIRTH DEFECTS RESEARCH, Issue 4 2007
Huiping Zhu
Abstract BACKGROUND: Periconceptional folic acid supplementation is widely believed to aid in the prevention of neural tube defects (NTDs), orofacial clefts, and congenital heart defects. Folate-binding proteins or receptors serve to bind folic acid and 5-methyltetrahydrofolate, representing one of the two major mechanisms of cellular folate uptake. METHODS: We herein describe abnormal cardiovascular development in mouse fetuses lacking a functional folate-binding protein gene (Folr1). We also performed a dose-response study with folinic acid and determined the impact of maternal folate supplementation on Folr1 nullizygous cardiac development. RESULTS: Partially rescued preterm Folr1,/, (formerly referred to as Folbp1) fetuses were found to have outflow tract defects, aortic arch artery abnormalities, and isolated dextracardia. Maternal supplementation with folinic acid rescued the embryonic lethality and the observed cardiovascular phenotypes in a dose-dependant manner. Maternal genotype exhibited significant impact on the rescue efficiency, suggesting an important role of in utero folate status in embryonic development. Abnormal heart looping was observed during early development of Folr1,/, embryos partially rescued by maternal folinic acid supplementation. Migration pattern of cardiac neural crest cells, genetic signals in pharyngeal arches, and the secondary heart field were also found to be affected in the mutant embryos. CONCLUSIONS: Our observations suggest that the beneficial effect of folic acid for congenital heart defects might be mediated via its impact on neural crest cells and by gene regulation of signaling pathways involved in the development of the pharyngeal arches and the secondary heart field. Birth Defects Research (Part A) 2007. © 2007 Wiley-Liss, Inc. [source]

Folic acid,containing supplement consumption during pregnancy and risk for oral clefts: A meta-analysis,

BIRTH DEFECTS RESEARCH, Issue 1 2007
Rachel L. Badovinac
Abstract BACKGROUND: There is equivocal evidence in the published literature that folic acid supplementation during pregnancy may protect against the common congenital anomalies cleft lip with or without cleft palate (CLP) and cleft palate alone (CP). We undertook this meta-analysis to test the hypothesis that nonsyndromic oral cleft birth prevalences are different for those whose mothers took folic acid,containing supplements and for those whose mothers did not. METHODS: Human studies published in English were identified through MEDLINE, bibliography reviews, and contacting experts in the field. Within strata of prospective and case-control studies, CLP, CP, and all clefts, respectively, were analyzed using either a fixed or random effects model, as appropriate. We assessed for publication bias using Begg and Mazumdar's rank correlation and Egger's regression-based tests. RESULTS: Five prospective studies were analyzed, yielding combined relative risks of 0.51 (95% CI: 0.32, 0.95) for CLP, 1.19 (95% CI: 0.43, 3.28) for CP, and 0.55 (95% CI: 0.32, 0.95) for all clefts. Twelve case-control studies were assessed, which resulted in combined relative risks of 0.77 (95% CI: 0.65, 0.90) for CLP, 0.80 (95% CI: 0.69, 0.93) for CP, and 0.78 (95% CI: 0.71, 0.85) for all clefts. CONCLUSIONS: In aggregate, our results support the hypothesis of a protective effect of folic acid,containing supplement intake during pregnancy on the risk for oral clefts, although this conclusion is tempered by the potential for bias and uncontrolled confounding. Birth Defects Research (Part A), 2007. © 2006 Wiley-Liss, Inc. [source]

Plasma vitamin values and antiepileptic therapy: Case reports of pregnancy outcomes affected by a neural tube defect

Folate concentrations and folic acid supplementation among women in their first trimester of pregnancy in a rural area with a high prevalence of neural tube defects in Shanxi, China

BIRTH DEFECTS RESEARCH, Issue 6 2006
Le Zhang
Abstract BACKGROUND: Although an information campaign concerning periconceptional folic acid supplementation was launched in 1998 in Shanxi Province, China, the prevalence of neural tube defects in rural areas was reported as high as 140 per 10,000 births in 2002. The blood folate concentrations and the practice of folic acid supplementation among pregnant women in rural areas of the province are described. METHODS: A total of 483 pregnant women (mean gestation, 8.1 weeks) in a rural area of Shanxi were interviewed. Nonfasting blood samples and information on folic acid supplementation were collected. Folate concentrations in plasma and erythrocytes were determined by a microbiological assay. RESULTS: The mean concentrations of plasma and erythrocyte folate for pregnant women was 10.4 nmol/liter and 375.8 nmol/liter, respectively. Deficiencies of plasma and erythrocyte folate were observed in 20.9% and 47.6% of women, respectively. Seasonal variations were noted in the prevalence of folate deficiency, with significantly lower plasma folate concentrations in spring and summer and lower erythrocyte folate concentrations in seasons other than summer. Among pregnant women, <10% reported having taken or currently taking folic acid, and virtually no women (0.6%) took folic acid as recommended. CONCLUSIONS: Women in rural areas had low plasma and erythrocyte folate levels, and folate deficiency was highly prevalent in the area. Few women followed the recommendations regarding folic acid supplementation, and the information campaign in Shanxi was unsuccessful. These findings suggest the urgent need for combined strategies in rural areas to fortify grain with folic acid and promote folic acid supplements for childbearing-age women. Birth Defects Research (Part A) 76:461,466, 2006. © 2006 Wiley-Liss, Inc. [source]

Evaluation of infant methylenetetrahydrofolate reductase genotype, maternal vitamin use, and risk of high versus low level spina bifida defects,

BIRTH DEFECTS RESEARCH, Issue 3 2003
Kelly A. Volcik
BACKGROUND Several studies have suggested that homozygosity for the C677T 5,10-methylenetetrahydrofolate reductase (MTHFR) variant is a potential risk factor for neural tube defects (NTDs), as individuals homozygous for the C677T allele have slightly elevated homocysteine concentrations under conditions of low folic acid intake. It has been hypothesized that maternal folic acid supplementation prevents NTDs by partially correcting reduced MTHFR activity associated with the variant form of the enzyme. METHODS Genomic DNA was extracted from newborn screening blood spots obtained from 145 infants with spina bifida (SB) and 260 nonmalformed control infants. The MTHFR C677T genotype was determined by restriction enzyme digestion of PCR amplification products with Hinf1. We investigated whether infant MTHFR genotype influenced the risk for the anatomic level of the SB lesion (high vs. low); we also explored whether maternal vitamin use influenced this risk. RESULTS Compared to controls, the frequency of SB infants with the homozygous 677 TT genotype was greatest in those infants with high level SB defects (26%; odds ratio [OR] = 2.9; 95% confidence interval [CI] = 0.9,10.1) than for those with low level SB defects (22%; OR = 1.8; 95% CI = 0.9,3.2). Furthermore, homozygous 677TT infants whose mothers did not use vitamins containing folic acid had a modestly increased risk of SB (OR = 1.8; 95% CI = 0.8,3.9), with this risk increasing more than three-fold (OR = 5.5; 95% CI = 0.8,28.1) for those infants with high level SB defects whose mothers did not use vitamins. CONCLUSIONS Based upon our observations, it is suggested that the association between the infant MTHFR homozygous variant genotype and spina bifida risk may be conditional upon both lesion level and maternal vitamin use. Birth Defects Research (Part A) 67:154,157, 2003. © 2003 Wiley-Liss, Inc. [source]

Toward understanding the genetic basis of neural tube defects

CLINICAL GENETICS, Issue 4 2007
Z Kibar
Neural tube defects (NTDs) represent a common group of severe congenital malformations that result from failure of neural tube closure during early development. Their etiology is quite complex involving environmental and genetic factors and their underlying molecular and cellular pathogenic mechanisms remain poorly understood. Animal studies have recently demonstrated an essential role for the planar cell polarity pathway (PCP) in mediating a morphogenetic process called convergent extension during neural tube formation. Alterations in members of this pathway lead to NTDs in vertebrate models, representing novel and exciting candidates for human NTDs. Genetic studies in NTDs have focused mainly on folate-related genes based on the finding that perinatal folic acid supplementation reduces the risk of NTDs by 60,70%. A few variants in these genes have been found to be significantly associated with an increased risk for NTDs. The candidate gene approach investigating genes involved in neurulation has failed to identify major causative genes in the etiology of NTDs. Despite this history of generally negative findings, we are achieving a rapid and impressive progress in understanding the genetic basis of NTDs, based mainly on the powerful tool of animal models. [source]