Isolation of complementary deoxyribonucleic acids encoding putative secreted and membrane-bound folate binding proteins from endometrium of swine.
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Two distinct forms of endometrial folate binding protein (FBP) cDNAs were isolated using reverse transcription-polymerase chain reaction and 3' and 5' rapid amplification of cDNA ends (RACE) procedures. On the basis of the absence or presence of an intact glycophosphatidylinositol linkage site in the C terminus of the predicted amino acid sequences, the two forms appear to encode secreted and membrane-bound forms of FBP. The cDNAs for the putative secreted and membrane forms encoded 252- and 249-amino acid proteins, respectively, that were 73% identical with each other and were 66-82% identical with other known FBPs. However, the nucleotide sequences within the 5' untranslated region and from codons 224 and 223 of the secreted and membrane forms, respectively, to the 3' ends of each RNA, were divergent. The divergence in the 3' ends of the two cDNAs was exploited to determine changes in concentrations of each mRNA in the endometrium during the estrous cycle and early pregnancy. Northern blots of endometrial total RNA probed with a putative secreted FBP specific probe indicated that mRNA concentrations do not change during early pregnancy. In contrast, blots probed with a putative membrane FBP specific probe indicated that mRNA concentrations increase dramatically from Day 15 to Day 24 of pregnancy. Finally, N-terminal amino acid sequencing of FBP purified from Day 15 pregnant uterine flushings matched the secreted form of FBP mRNA. These data are consistent with a role for putative secreted and membrane-bound forms of FBPs in the transport of folate to the developing swine conceptus during early pregnancy. (+info)
Serum levels of folic acid and vitamin B12 in Korean patients with vitiligo.
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The association of vitiligo and pernicious anemia has been previously documented. The low levels of folic acid and vitamin B12 were thought to be related to vitiligo. To date, there have been very few reports about the serum levels of folic acid and vitamin B12 in patients with vitiligo. Using radioimmunoassay, we measured the serum levels of folic acid and vitamin B12 in 100 Korean patients with vitiligo. The mean serum levels of folic acid and vitamin B12 were 6.31 +/- 2.82 ng/ml and 630.25 +/- 230.94 pg/ml, respectively, in patients with vitiligo. These levels showed no significant difference compared to the normal control group, suggesting that folic acid and vitamin B12 do not appear to play a role in the pathogenesis of vitiligo. (+info)
Maternal zinc supplementation does not affect size at birth or pregnancy duration in Peru.
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To estimate the effect of maternal zinc deficiency on pregnancy outcomes, we conducted a zinc supplementation trial in an urban shantytown in Lima, Peru, a population with habitual low zinc intakes. Beginning at 10-24 wk gestation, 1295 mothers were randomly assigned to receive prenatal supplements containing 60 mg iron and 250 (g folate, with or without 15 mg zinc. Women were followed up monthly during pregnancy. At birth, newborn weight was recorded, and crownheel length, head circumference and other circumferences and skinfold thicknesses were assessed on d 1. At delivery, 1016 remained in the study; duration of pregnancy was known for all women, and birth weight information was available for 957 newborns. No differences were noted in duration of pregnancy (39.4 +/- 2.2 vs. 39. 5 +/- 2.0 wk) or birth weight (3267 +/- 461 vs. 3300 +/- 498 g) by prenatal supplement type (iron + folate + zinc vs. iron + folate; P > 0.05), and there were no differences in the rates of preterm (<37 wk) or post-term (>42 wk) delivery, low birth weight (<2500 g) or high birth weight (>4000 g). Finally, there were no differences by prenatal supplement type in newborn head circumference, crownheel length, chest circumference, mid-upper arm circumference, calf circumference or skinfold thickness at any of three sites. Adjustment for covariates and confounding factors did not alter these results. Adding zinc to prenatal iron and folate tablets did not affect duration of pregnancy or size at birth in this population. (+info)
The role of folic acid in oral clefting.
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The objective of this study is to describe the role of periconceptional folic acid supplementation and assess it's potential in the prevention of foetal abnormalities, and consists of a review of the literature undertaken using an electronic and hand search. This includes research trials and methodology associated with folic acid supplementation. It is recommended that all women planning to conceive should supplement their diet with folic acid in order to prevent abnormalities in neural tube development, particularly if there is a history of a previously affected pregnancy. There is increasing evidence that folic acid supplementation may, in addition, reduce the incidence of oral facial clefting. Further research with multi-disciplinary approaches in biochemistry, genetics, gene/environment interactions, and embryology are indicated. (+info)
Effects of oral folic acid supplementation on endothelial function in familial hypercholesterolemia. A randomized placebo-controlled trial.
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BACKGROUND: Folates have been suggested to be of benefit in reducing cardiovascular risk. The present study was designed to examine whether oral folic acid supplementation could improve endothelial function as an intermediate end point for cardiovascular risk in patients with increased risk of atherosclerosis due to familial hypercholesterolemia (FH). METHODS AND RESULTS: In a prospective, randomized, double-blind, placebo-controlled study with crossover design, we evaluated the effects of 4 weeks of treatment with oral folic acid (5 mg PO) on endothelial function in FH. In 20 FH patients, forearm vascular function was assessed at baseline, after 4 weeks of folic acid treatment, and after 4 weeks of placebo treatment by venous occlusion plethysmography, with serotonin and sodium nitroprusside used as endothelium-dependent and -independent vasodilators. In addition, we examined the vasoconstrictor response to the NO synthase inhibitor N(G)-monomethyl-L-arginine to assess basal NO activity. In FH patients, folic acid supplementation restored the impaired endothelium-dependent vasodilation, whereas it did not significantly influence endothelium-independent vasodilation or basal forearm vasomotion. There was a trend toward improvement in basal NO activity. CONCLUSIONS: These data demonstrate that oral supplementation of folic acid can improve endothelial function in patients with increased risk of atherosclerotic disease due to hypercholesterolemia, without changes in plasma lipids. (+info)
Preventing neural tube defects. Survey of preconceptional use of folic acid.
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OBJECTIVE: To determine the proportion of women who take daily folic acid supplements in the month before conception and to identify factors associated with supplement use. DESIGN: Cross-sectional survey by self-administered questionnaire. SETTING: Tertiary care teaching hospital in Hamilton, Ont. PARTICIPANTS: Four hundred eighty-four (43%) of 1132 women who delivered normal babies between November 1997 and March 1998. MAIN OUTCOME MEASURES: Reports of daily vitamin supplement use in the month before pregnancy and after pregnancy, and having heard or read about the need to take folic acid before pregnancy; sources of information about folic acid; factors associated with preconceptional vitamin use. RESULTS: Thirty-four percent of respondents reported taking vitamins before conception (use ranged from 21% for those with unplanned pregnancies to 40% for those with planned pregnancies); 80% after conception. Of all respondents, 63% were aware of the need for preconceptional folic acid. Key information sources were family doctors and the mass media: the media were more important before conception, doctors after. Being older (30 years or more), having post-secondary education, and having a planned pregnancy were associated with knowing about the benefits of folic acid; knowledge, regular exercise, perceived good health, and planned pregnancy were associated with preconceptional use of vitamins. CONCLUSIONS: Even in this sample of well educated, English-speaking women, only one third took vitamin supplements before conception, which indicates that current educational efforts do not reach most women early enough. A coordinated, multi-pronged strategy that targets and involves physicians and capitalizes on opportunities to work with schools, public health outlets, and the media is needed. (+info)
Estimated folate intakes: data updated to reflect food fortification, increased bioavailability, and dietary supplement use.
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BACKGROUND: There is a critical need to estimate dietary folate intakes for nutrition monitoring and food safety evaluations, but available intake data are seriously limited by several factors. OBJECTIVE: Our objective was to update 2 national food consumption surveys to reflect folate intakes as a result of the recently initiated food fortification program and to correct folate intakes for the apparently higher bioavailability of synthetic folic acid (SFA; ie, folate added to foods or from dietary supplements) than of naturally occurring folate so as to express intakes as dietary folate equivalents. DESIGN: It was not possible to chemically analyze foods, so adjustments were made to food-composition data by using information about food ingredients and characteristics. Total folate intakes were estimated for several sex and age groups by using the modified data coupled with dietary supplement use. RESULTS: Within the limitations of the data, our findings suggested that 67-95% of the population met or surpassed the new estimated average requirement, depending on the sex and age group and survey. Nonetheless, some subgroups had estimated intakes below these standards. Estimated SFA intakes suggested that approximately 15-25% of children aged 1-8 y, depending on the survey, had intakes above the newly established tolerable upper intake level. We estimated that 68-87% of females of childbearing age had SFA intakes below the recommended intake of 400 microgram/d, depending on the age group and survey. CONCLUSION: There is a need to explore ways to improve folate intakes in targeted subgroups, including females of childbearing age, while not putting other population groups at risk of excessive intakes. (+info)
Fortification with low amounts of folic acid makes a significant difference in folate status in young women: implications for the prevention of neural tube defects.
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BACKGROUND: Mandatory fortification of grain products with folic acid was introduced recently in the United States, a policy expected to result in a mean additional intake of 100 microgram/d. One way of predicting the effectiveness of this measure is to determine the effect of removing a similar amount of folic acid as fortified food from the diets of young women who had been electively exposed to chronic fortification. OBJECTIVE: The objective was to examine the effect on folate status of foods fortified with low amounts of folic acid. DESIGN: We investigated the changes in dietary intakes and in red blood cell and serum concentrations of folate in response to removing folic acid-fortified foods for 12 wk from the diets of women who reportedly consumed such foods at least once weekly (consumers). RESULTS: Consumers (n = 21) had higher total folate intakes (P = 0.002) and red blood cell folate concentrations (P = 0.023) than nonconsumers (women who consumed folic acid-fortified foods less than once weekly; n = 30). Of greater interest, a 12-wk intervention involving the exclusion of these foods resulted in a decrease in folate intake of 78 +/- 56 microgram/d (P < 0.001), which was reflected in a significant reduction in red blood cell folate concentrations (P < 0.05). CONCLUSIONS: Cessation of eating folic acid-fortified foods resulted in removing 78 microgram folic acid/d from the diet. Over 12 wk this resulted in a lowering of red blood cell folate concentrations by 111 nmol/L (49 microgram/L). This magnitude of change in folate status in women can be anticipated as a result of the new US fortification legislation and is predicted to have a significant, although not optimal, effect in preventing neural tube defects. (+info)