The Inclusion of Folic Acid in Weekly Iron-Folic Acid Supplements Confers no Additional Benefit on Anemia Reduction in Nonpregnant Women: A Randomized Controlled Trial in Malaysia.

BACKGROUND: Weekly iron-folic acid (IFA) supplements are recommended for all menstruating women in countries where anemia prevalence is ≥20%; however, it is unknown whether the inclusion of folic acid in weekly IFA supplements reduces anemia. OBJECTIVES: We examined whether the inclusion of folic acid in weekly IFA supplements conferred any benefit on hemoglobin (Hb) concentration, anemia reduction, or iron status [ferritin and soluble transferrin receptor (sTfR)], over iron alone. METHODS: In this secondary analysis of a randomized controlled trial in Malaysia, n = 311 nonpregnant women (18-45 y old) received 60 mg Fe with either 0, 0.4, or 2.8 mg folic acid once-weekly for 16 wk. Fasting blood was collected at baseline and 16 wk. A generalized linear model (normal distribution with identity link) was used to assess Hb concentration at 16 wk (primary outcome). RESULTS: At baseline, 84% of women had low folate status (plasma folate < 14 nmol/L). At 16 wk, marginal mean (95% CI) Hb was 131 (130, 133), 131 (129, 132), and 132 (130, 133) g/L; ferritin was 58.2 (53.9, 62.5), 56.5 (52.2, 60.9), and 58.0 (53.7, 62.3) µg/L; and sTfR was 5.8 (5.5, 6.1), 5.8 (5.5, 6.1), and 5.9 (5.6, 6.2) mg/L in the 0, 0.4, and 2.8 mg/wk groups, respectively, with no differences between groups (P > 0.05). Baseline plasma folate concentration did not modify the effect of treatment on Hb concentration at 16 wk. Among all women, the risks of anemia [risk ratio (RR): 0.65; 95% CI: 0.45, 0.96; P = 0.03] and iron deficiency based on ferritin (RR: 0.30; 95% CI: 0.20, 0.44; P < 0.001) were lower at 16 wk than at baseline. CONCLUSIONS: Despite the low folate status among these nonpregnant Malaysian women, the inclusion of folic acid in weekly IFA supplements did not reduce anemia or improve iron status, over iron alone. However, the benefits of folic acid for neural tube defect prevention still warrant its retention in weekly IFA supplements.This trial was registered at www.anzctr.org.au as ACTRN12619000818134.

Weekly iron-folic acid supplements containing 2.8 mg folic acid are associated with a lower risk of neural tube defects than the current practice of 0.4 mg: a randomised controlled trial in Malaysia.

INTRODUCTION: Weekly iron-folic acid (IFA) supplements are recommended for all menstruating women in countries where anaemia prevalence is >20%. Anaemia caused by folate deficiency is low worldwide, and the need to include folic acid is in question. Including folic acid might reduce the risk of a neural tube defect (NTD) should a woman become pregnant. Most weekly supplements contain 0.4 mg folic acid; however, WHO recommends 2.8 mg because it is seven times the daily dose effective in reducing NTDs. There is a reluctance to switch to supplements containing 2.8 mg of folic acid because of a lack of evidence that this dose would prevent NTDs. Our aim was to investigate the effect of two doses of folic acid, compared with placebo, on red blood cell (RBC) folate, a biomarker of NTD risk. METHODS: We conducted a three-arm double-blind efficacy trial in Malaysia. Non-pregnant women (n=331) were randomised to receive 60 mg iron and either 0, 0.4, or 2.8 mg folic acid once weekly for 16 weeks. RESULTS: At 16 weeks, women receiving 0.4 mg and 2.8 mg folic acid per week had a higher mean RBC folate than those receiving 0 mg (mean difference (95% CI) 84 (54 to 113) and 355 (316 to 394) nmol/L, respectively). Women receiving 2.8 mg folic acid had a 271 (234 to 309) nmol/L greater mean RBC folate than those receiving 0.4 mg. Moreover, women in the 2.8 mg group were seven times (RR 7.3, 95% CI 3.9 to 13.7; p<0.0001) more likely to achieve an RBC folate >748 nmol/L, a concentration associated with a low risk of NTD, compared with the 0.4 mg group. CONCLUSION: Weekly IFA supplements containing 2.8 mg folic acid increases RBC folate more than those containing 0.4 mg. Increased availability and access to the 2.8 mg formulation is needed. TRAIL REGISTRATION NUMBER: This trial is registered with the Australian New Zealand Clinical Trial Registry (ACTRN12619000818134).

Scaled-up nutrition education on pulse-cereal complementary food practice in Ethiopia: a cluster-randomized trial.

BACKGROUND: Improving children's weight status through nutrition education (NE) for mothers about using pulses in complementary feeding has been demonstrated in pilot studies, but no effect on stunting was reported. The aim of the study was to assess the impact of a 9-month pulse-nutrition education program on improving mothers' knowledge, attitude, and practices (KAP) towards pulses, as well as its effect on children's diet diversity, and nutritional status. The NE was delivered by Health Extension Workers (HEWs). METHODS: A cluster randomized study was employed for the community-based interventional study. Twelve randomly selected villages in Sidama Zone, Southern Ethiopia were included in the study. A total of 772 mother-child pairs involved in the study; where 386 mother-child pairs in the intervention group received additional messages about pulse-cereal complementary food, and 386 pairs (the control) received only routine health education for 9 months. A survey on mothers' KAP and anthropometric measurements of the children were taken at baseline, midpoint, and end point. ANOVA and descriptive statistics were used to analyzed data. RESULTS: At baseline and end point, maternal KAP and the dietary diversity score of the children (mean age at end point 18.8 ± 2.9 mo) were assessed. Intervention mothers' KAP improved (p < 0.001) at midpoint and end point compared to that of the control group, as did frequency of pulse consumption and Dietary Diversity Score (DDS) among children. At 9 months, the prevalence of stunting, wasting, and underweight was significantly reduced in the intervention group compared to the control group (p = 0.001). CONCLUSIONS: NE delivered by HEWs improved KAP of mothers regarding pulse consumption and dietary diversity of children led to improved nutritional status of the children. Training HEWs on the use of pulses for complementary food may be an effective way to improve the health of children in Ethiopian communities. TRIAL REGISTRATION: Clinicaltrials.gov # NCT02638571 . Date of registration: 12/18/2015. Prospectively registered.

Dietary Choline Intake: Current State of Knowledge Across the Life Cycle.

Choline, an essential dietary nutrient for humans, is required for the synthesis of the neurotransmitter, acetylcholine, the methyl group donor, betaine, and phospholipids; and therefore, choline is involved in a broad range of critical physiological functions across all stages of the life cycle. The current dietary recommendations for choline have been established as Adequate Intakes (AIs) for total choline; however, dietary choline is present in multiple different forms that are both water-soluble (e.g., free choline, phosphocholine, and glycerophosphocholine) and lipid-soluble (e.g., phosphatidylcholine and sphingomyelin). Interestingly, the different dietary choline forms consumed during infancy differ from those in adulthood. This can be explained by the primary food source, where the majority of choline present in human milk is in the water-soluble form, versus lipid-soluble forms for foods consumed later on. This review summarizes the current knowledge on dietary recommendations and assessment methods, and dietary choline intake from food sources across the life cycle.

Variations in plasma choline and metabolite concentrations in healthy adults.

BACKGROUND: Plasma concentrations of choline and its metabolites might serve as biomarkers for the health outcomes of several pathological states such as cardiovascular disease and cancer. However, information about the reliability of biomarkers of choline status is limited. We investigated biological variations in repeated measures of choline and metabolites in healthy adults to assess them as biomarkers. METHODS: Blood samples were collected after an overnight fast at three-time points 12 days apart from 40 adults (mean age, 33 y; male, n = 21). A subset (n = 19; [male, n = 8]) provided one additional sample after a breakfast meal. Plasma free choline, betaine and dimethylglycine were measured using liquid chromatography-tandem mass spectrometry, and plasma phosphatidylcholine, sphingomyelin and lysophosphatidylcholine were measured using high-performance liquid chromatography. RESULTS: The biological variations observed for choline and metabolites were ≤ 13% for adult fasting samples. This corresponded to intra-class correlations (ICC) that ranged from 0.593 to 0.770 for fasting values for choline and metabolites. A similar ICC range was also obtained between fasting and post-prandial states. Although most post-prandial concentrations of choline and metabolites were significantly higher (P < .05) than fasting, all fell within a calculated reference interval. The participants were correctly classified in tertiles for fasting and post-prandial states for choline (68%) and metabolites (range = 32% phosphatidylcholine and 79% for sphingomyelin). CONCLUSIONS: These findings indicate that biological variations of choline and metabolites are low in healthy adults and values from a single blood sample can be used as a biomarker. However, choosing phosphatidylcholine as a biomarker is less reliable.

Randomized controlled trial assessing the efficacy of a reusable fish-shaped iron ingot to increase hemoglobin concentration in anemic, rural Cambodian women.

Background: Anemia affects 45% of women of childbearing age in Cambodia. Iron supplementation is recommended in populations in which anemia prevalence is high. However, there are issues of cost, distribution, and adherence. A potential alternative is a reusable fish-shaped iron ingot, which, when added to the cooking pot, leaches iron into the fluid in which it is prepared.Objective: We sought to determine whether there was a difference in hemoglobin concentrations in rural Cambodian anemic women (aged 18-49 y) who cooked with the iron ingot or consumed a daily iron supplement compared with a control after 1 y.Design: In Preah Vihear, 340 women with mild or moderate anemia were randomly assigned to 1) an iron-ingot group, 2) an iron-supplement (18 mg/d) group, or 3) a nonplacebo control group. A venous blood sample was taken at baseline and at 6 and 12 mo. Blood was analyzed for hemoglobin, serum ferritin, and serum transferrin receptor. Hemoglobin electrophoresis was used to detect structural hemoglobin variants.Results: Anemia prevalence was 44% with the use of a portable hemoglobinometer during screening. At baseline, prevalence of iron deficiency was 9% on the basis of a low serum ferritin concentration. There was no significant difference in mean hemoglobin concentrations between the iron-ingot group (115 g/L; 95% CI: 113, 118 g/L; P = 0.850) or iron-supplement group (115 g/L; 95% CI: 113, 117 g/L; P = 0.998) compared with the control group (115 g/L; 95% CI: 113, 117 g/L) at 12 mo. Serum ferritin was significantly higher in the iron-supplement group (73 µg/L; 95% CI: 64, 82 µg/L; P = 0.002) than in the control group at 6 mo; however, this significance was not maintained at 12 mo (73 µg/L; 95% CI: 58, 91 µg/L; P = 0.176).Conclusions: Neither the iron ingot nor iron supplements increased hemoglobin concentrations in this population at 6 or 12 mo. We do not recommend the use of the fish-shaped iron ingot in Cambodia or in countries where the prevalence of iron deficiency is low and genetic hemoglobin disorders are high. This trial was registered at clinicaltrials.gov as NCT02341586.

Comparison of four immunoassays to measure serum ferritin concentrations and iron deficiency prevalence among non-pregnant Cambodian women and Congolese children.

BACKGROUND: Global standardization of ferritin assays is lacking, which could have direct implications on the accurate measurement and comparability of ferritin concentration and iron deficiency (ID) prevalence rates in at-risk populations. METHODS: We measured serum ferritin concentrations using four immunoassays: the s-ELISA and the AxSYM™ analyzer were compared among 420 non-pregnant Cambodian women; the Centaur® XP analyzer, s-ELISA, and AxSYM™ analyzer were compared among a subset of 100 Cambodian women; and the s-ELISA and the Elecsys® 2010 analyzer were compared among 226 Congolese children aged 6-59 months. RESULTS: Median ferritin concentrations (adjusted for inflammation) ranged between 48 and 91 µg/L among Cambodian women and between 54 and 55 µg/L among Congolese children. ID prevalence ranged from 2% to 10% among Cambodian women and 5% to 7% among Congolese children. Bias between methods varied widely (-9 to 45 µg/L) among women, and was 43 µg/L among children. Bias was lower when ferritin values outside of the s-ELISA measurement range (>250 µg/L) were excluded. CONCLUSIONS: The observed differences in ferritin concentrations likely reflect different ferritin isoforms, antibodies, and calibrators used across assays and by different laboratories. However, despite differences in ferritin concentrations, ID prevalence was relatively similar and low across all methods.

Elevated levels of iron in groundwater in Prey Veng province in Cambodia: a possible factor contributing to high iron stores in women.

Iron is a natural element found in food, water and soil and is essential for human health. Our aim was to determine the levels of iron and 25 other metals and trace elements in groundwater from 22 households in Prey Veng, Cambodia. Water analyses were conducted using inductively coupled plasma-mass spectrometry and optical emission spectrometry. Compared to the 2011 World Health Organization guidelines for drinking water quality, aluminum, iron and manganese exceeded maximum levels (in 4.5, 72.7 and 40.9% of samples, respectively). Compared to the 2004 Cambodian drinking water quality standards, iron and manganese exceeded maximum levels (in 59.1 and 36.4% of samples, respectively). We found no evidence of arsenic contamination. Guidelines for iron were established primarily for esthetic reasons (e.g. taste), whereas other metals and elements have adverse effects associated with toxicity. Iron in groundwater ranged from 134 to 5,200 µg/L (mean ∼1,422 µg/L). Based on a daily consumption of 3 L groundwater, this equates to ∼0.4-15.6 mg iron (mean ∼4.3 mg/day), which may be contributing to high iron stores and the low prevalence of iron deficiency anemia in Prey Veng women. Elevated levels of manganese in groundwater are a concern and warrant further investigation.

Genetic hemoglobin disorders rather than iron deficiency are a major predictor of hemoglobin concentration in women of reproductive age in rural prey Veng, Cambodia.

BACKGROUND: Anemia is common in Cambodian women. Potential causes include micronutrient deficiencies, genetic hemoglobin disorders, inflammation, and disease. OBJECTIVES: We aimed to investigate factors associated with anemia (low hemoglobin concentration) in rural Cambodian women (18-45 y) and to investigate the relations between hemoglobin disorders and other iron biomarkers. METHODS: Blood samples were obtained from 450 women. A complete blood count was conducted, and serum and plasma were analyzed for ferritin, soluble transferrin receptor (sTfR), folate, vitamin B-12, retinol binding protein (RBP), C-reactive protein (CRP), and α1 acid glycoprotein (AGP). Hemoglobin electrophoresis and multiplex polymerase chain reaction were used to determine the prevalence and type of genetic hemoglobin disorders. RESULTS: Overall, 54% of women had a genetic hemoglobin disorder, which included 25 different genotypes (most commonly, hemoglobin E variants and α(3.7)-thalassemia). Of the 420 nonpregnant women, 29.5% had anemia (hemoglobin <120 g/L), 2% had depleted iron stores (ferritin <15 µg/L), 19% had tissue iron deficiency (sTfR >8.3 mg/L), <3% had folate deficiency (<3 µg/L), and 1% had vitamin B-12 deficiency (<150 pmol/L). Prevalences of iron deficiency anemia (IDA) were 14.2% and 1.5% in those with and without hemoglobin disorders, respectively. There was no biochemical evidence of vitamin A deficiency (RBP <0.7 µmol/L). Acute and chronic inflammation were prevalent among 8% (CRP >5 mg/L) and 26% (AGP >1 g/L) of nonpregnant women, respectively. By using an adjusted linear regression model, the strongest predictors of hemoglobin concentration were hemoglobin E homozygous disorder and pregnancy status. Other predictors were 2 other heterozygous traits (hemoglobin E and Constant Spring), parity, RBP, log ferritin, and vitamin B-12. CONCLUSIONS: Multiple biomarkers for anemia and iron deficiency were significantly influenced by the presence of hemoglobin disorders, hence reducing their diagnostic sensitivity. Further investigation of the unexpectedly low prevalence of IDA in Cambodian women is warranted.

25-Hydroxyvitamin D concentrations in children with Crohn's disease supplemented with either 2000 or 400 IU daily for 6 months: a randomized controlled study.

OBJECTIVES: To assess vitamin D status of pediatric patients with Crohn's disease (CD) and to compare their serum 25-hydroxyvitamin D (s-25OHD) with established cutoffs and assess whether 6 months of supplementation with 2000 IU/d, vs 400 IU/d, would reduce the group prevalence of vitamin D below these cutoffs. STUDY DESIGN: Subjects 8-18 years (n = 83) with quiescent CD were randomized to either 400 or 2000 IU vitamin D3/d for 6 months. RESULTS: Baseline mean ± SD s-25OHD was 24 ± 8 ng/mL; 13 subjects (16%) had an s-25OHD <16 ng/mL, 27 (33%) < 20 ng/mL, and 65 (79%) < 30 ng/mL. There was no significant difference between groups in achieving the cutoffs of 16 ng/mL or 20 ng/mL at 6 months; however, only 35% of the 400 IU group achieved the greater cutoff of 30 ng/mL compared with 74% in the 2000 IU group (P < .001). Baseline adjusted mean s-25OHD concentrations at 6 months were 9.6 ng/mL (95% CI 6.0-13.2, P < .001) greater in the 2000 IU than the 400 IU group. Disease activity was not affected by supplement dose. Few subjects exceeded safety marker cutoffs, and this did not differ by dose. CONCLUSIONS: At baseline, a high proportion of patients had a mean s-25OHD >20 ng/mL. 2000 IU vitamin D3/d is more effective in raising s-25OHD concentrations to > 30 ng/mL in children with CD than 400 IU/d, but both treatments were equally effective at achieving 16 or 20 ng/mL.

Methyl nutrients, DNA methylation, and cardiovascular disease.

Diet plays an important role in the development and prevention of cardiovascular disease (CVD), but the molecular mechanisms are not fully understood. DNA methylation has been implicated as an underlying molecular mechanism that may account for the effect of dietary factors on the development and prevention of CVD. DNA methylation is an epigenetic process that provides "marks" in the genome by which genes are set to be transcriptionally activated or silenced. Epigenomic marks are heritable but are also responsive to environmental shifts, such as changes in nutritional status, and are especially vulnerable during development. S-adenosylmethionine is the methyl group donor for DNA methylation and several nutrients are required for the production of S-adenosylmethionine. These methyl nutrients include vitamins (folate, riboflavin, vitamin B12, vitamin B6, choline) and amino acids (methionine, cysteine, serine, glycine). As such, imbalances in the metabolism of these nutrients have the potential to affect DNA methylation. The focus of this review is to provide an overview on the current understanding of the relationship between methyl nutrient status and DNA methylation patterns and the potential role of this interaction in CVD pathology.

Ontogeny and water temperature influences the antiviral response of the Pacific oyster, Crassostrea gigas.

Disease is caused by a complex interaction between the pathogen, environment, and the physiological status of the host. Determining how host ontogeny interacts with water temperature to influence the antiviral response of the Pacific oysters, Crassostrea gigas, is a major goal in understanding why juvenile Pacific oysters are dying during summer as a result of the global emergence of a new genotype of the Ostreid herpesvirus, termed OsHV-1 µvar. We measured the effect of temperature (12 vs 22 °C) on the antiviral response of adult and juvenile C. gigas injected with poly I:C. Poly I:C up-regulated the expression of numerous immune genes, including TLR, MyD88, IκB-1, Rel, IRF, MDA5, STING, SOC, PKR, Viperin and Mpeg1. At 22 °C, these immune genes showed significant up-regulation in juvenile and adult oysters, but the majority of these genes were up-regulated 12 h post-injection for juveniles compared to 26 h for adults. At 12 °C, the response of these genes was completely inhibited in juveniles and delayed in adults. Temperature and age had no effect on hemolymph antiviral activity against herpes simplex virus (HSV-1). These results suggest that oysters rely on a cellular response to minimise viral replication, involving recognition of virus-associated molecular patterns to induce host cells into an antiviral state, as opposed to producing broad-spectrum antiviral compounds. This cellular response, measured by antiviral gene expression of circulating hemocytes, was influenced by temperature and oyster age. We speculate whether the vigorous antiviral response of juveniles at 22 °C results in an immune-mediated disorder causing mortality.

Adiposity and the relationship between vitamin D and blood pressure.

OBJECTIVE: Circulating vitamin D (25OHD) concentrations are negatively associated with blood pressure (BP) but little is known about the mechanisms for this relationship. Adiposity is positively associated with BP and inversely with circulating 25OHD concentrations but no studies have assessed the relationship between plasma 25OHD and adiposity on BP. The goal of this study is to investigate if the association between plasma 25OHD and BP is mediated by adiposity. MATERIALS/METHODS: The relationship between plasma 25OHD, systolic and diastolic BP, and adiposity [BMI, waist circumference, visceral adipose tissue (VAT)] was assessed in a multi-ethnic cross-sectional study of Aboriginal (n=151), Chinese (n=190), European (n=170), and South Asian (n=176) participants by linear regression models. RESULTS: Plasma 25OHD concentrations were negatively associated with systolic (standardized B=-0.191, P<0.001) and diastolic BP (standardized B=-0.196, P<0.001) in models adjusted for age, sex, ethnicity, family history of CVD, smoking status, alcohol consumption, and physical activity. The negative relationship between plasma 25OHD concentrations and systolic and diastolic BP was attenuated after the addition of BMI, waist circumference, and VAT to the models, but the relationship remained significant. Plasma 25OHD concentrations accounted for 0.7% and 0.8% of the variance in systolic and diastolic BP, respectively. CONCLUSION: These findings suggest that the relationship between vitamin D and BP is independent of adiposity. Further studies are required to determine the mechanisms by which vitamin D affects BP.

The majority of older British Columbians take vitamin D-containing supplements.

OBJECTIVES: Health Canada recommends vitamin D supplements (10 microg/d) for Canadians aged > or = 50 years, but no data are available on adoption of this recommendation. Accordingly, this study was conducted to determine the current use of vitamin D supplements among British Columbian adults 50 years and over, and to explore relationships among vitamin D supplement use, socio-demographic variables, and knowledge, attitudes and beliefs about vitamin supplementation. METHODS: A population-representative stratified sample, recruited by random-digit dialling, completed a telephone-administered survey in late fall of 2008. Respondents provided details on supplements used in the past month (dosage, frequency, etc.) and demographic data, and responded to statements reflecting health beliefs about supplements, from which a Supplement Health Belief score was calculated. Eligible non-respondents indicated their age, sex, and whether they had used a supplement within the past month. RESULTS: Similar proportions of participants (n = 969) and non-respondents (n = 1,027) reported any supplement use in the past month. Among participants, 60% had used a vitamin D supplement (median intake among supplement users was 10 microg/d) and 3% exceeded the Tolerable Upper Intake Level of 50 microg/d. In multivariate analysis, vitamin D supplementation was significantly associated with female sex, not smoking, higher educational attainment, having a health care professional recommend supplement use, and a higher Supplement Health Belief score. CONCLUSION: Although most older adults used a vitamin D supplement, further dissemination of this recommendation is needed.

Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations.

Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease but lowering tHcy with B-vitamins, including folate, has generally not reduced vascular events in secondary prevention trials. Elevated plasma S-adenosylhomocysteine (AdoHcy) concentration may be a more sensitive indicator of vascular disease than plasma tHcy. However, unlike tHcy, plasma AdoHcy did not correlate with folate concentration in one study indicating that folate supplementation may not lower AdoHcy. Our aim was to determine whether providing B-vitamin supplements to healthy older people with elevated tHcy (>13 micromol/l) affects plasma AdoHcy and S-adenosylmethionine (AdoMet) concentrations. Healthy older participants (n 276; > or = 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B12 (500 microg) and vitamin B6 (10 mg), or placebo, for 2 years. Of these participants, we selected the first fifty participants in each treatment group and measured plasma AdoHcy and AdoMet. Plasma tHcy was 4.4 (95 % CI 3.2, 5.6; P < 0.001) micromol/l lower at 2 years in the vitamins group compared with the placebo group. At 2 years, there were no significant differences in plasma AdoMet (+4 % (95 % CI - 2, 11); P = 0.19), AdoHcy ( - 1 % (95 % CI - 10, 8); P = 0.61) or the AdoMet:AdoHcy ratio (0.22 (95 % CI - 0.04, 0.49); P = 0.10) between the two groups. In conclusion, B-vitamin supplementation of older people lowered plasma tHcy but had no effect on plasma AdoMet or AdoHcy concentration. If elevated plasma AdoHcy is detrimental, this may explain why B-vitamins have generally failed to reduce vascular events in clinical trials.

Differential expression of genes encoding anti-oxidant enzymes in Sydney rock oysters, Saccostrea glomerata (Gould) selected for disease resistance.

Sydney rock oysters (Saccostrea glomerata) selectively bred for disease resistance (R) and wild-caught control oysters (W) were exposed to a field infection of disseminating neoplasia. Cumulative mortality of W oysters (31.7%) was significantly greater than R oysters (0.0%) over the 118 days of the experiment. In an attempt to understand the biochemical and molecular pathways involved in disease resistance, differentially expressed sequence tags (ESTs) between R and W S. glomerata hemocytes were identified using the PCR technique, suppression subtractive hybridisation (SSH). Sequencing of 300 clones from two SSH libraries revealed 183 distinct sequences of which 113 shared high similarity to sequences in the public databases. Putative function could be assigned to 64 of the sequences. Expression of nine ESTs homologous to genes previously shown to be involved in bivalve immunity was further studied using quantitative reverse-transcriptase PCR (qRT-PCR). The base-line expression of an extracellular superoxide dismutase (ecSOD) and a small heat shock protein (sHsP) were significantly increased, whilst peroxiredoxin 6 (Prx6) and interferon inhibiting cytokine factor (IK) were significantly decreased in R oysters. From these results it was hypothesised that R oysters would be able to generate the anti-parasitic compound, hydrogen peroxide (H(2)O(2)) faster and to higher concentrations during respiratory burst due to the differential expression of genes for the two anti-oxidant enzymes of ecSOD and Prx6. To investigate this hypothesis, protein extracts from hemolymph were analysed for oxidative burst enzyme activity. Analysis of the cell free hemolymph proteins separated by native-polyacrylamide gel electrophoresis (PAGE) failed to detect true superoxide dismutase (SOD) activity by assaying dismutation of superoxide anion in zymograms. However, the ecSOD enzyme appears to generate hydrogen peroxide, presumably via another process, which is yet to be elucidated. This corroborates our hypothesis, whilst phylogenetic analysis of the complete coding sequence (CDS) of the S. glomerata ecSOD gene is supportive of the atypical nature of the ecSOD enzyme. Results obtained from this work further the current understanding of the molecular mechanisms involved in resistance to disease in this economically important bivalve, and shed further light on the anomalous oxidative processes involved.

Folate and vitamin B12 status of women of reproductive age living in Hanoi City and Hai Duong Province of Vietnam.

OBJECTIVES: To assess the folate and vitamin B12 status of a group of Vietnamese women of reproductive age and to estimate the rate of neural tube defects (NTD) based on red blood cell (RBC) folate concentrations. DESIGN AND SUBJECTS: A representative sample of non-pregnant women (15-49 years) living in Hanoi City (n 244) and Hai Duong Province (n 245). MEASURES: RBC folate, plasma vitamin B12 and plasma holo-transcobalamin (holoTC), a sensitive indicator of vitamin B12 status. RESULTS: Mean (95% CI) concentrations of RBC folate, plasma B12 and plasma holoTC were 856 (837, 876) nmol/l, 494 (475, 513) pmol/l and 78 (74, 82) pmol/l, respectively. Only 3% and 4% of women had plasma B12 and holoTC concentrations indicative of deficiency. No woman had an RBC folate concentration indicative of deficiency (<317 nmol/l). Only 47% of women had an RBC folate concentration > or = 905 nmol/l. Accordingly, we predict the NTD rate in these regions of Vietnam to be 14.7 (14.2, 15.1) per 10,000 pregnancies. CONCLUSION: There was no evidence of folate and vitamin B12 deficiency among this population of Vietnamese women. However, suboptimal folate status may be placing three out of five women at increased risk of NTD. Reductions in NTD rates are still possible and women would benefit from additional folic acid during the periconceptional period from either supplements or fortified foods.

Serum n-3 long-chain PUFA differ by sex and age in a population-based survey of New Zealand adolescents and adults.

A higher proportion of n-3 long-chain PUFA in tissue lipids has been associated with a lower risk of CVD and some cancers. Diet is an important predictor of n-3 long-chain PUFA composition; however, the importance of non-dietary factors such as sex and age is unclear. We measured the proportion of n-3 long-chain PUFA in serum phospholipid, cholesterol ester and TAG of 2793 New Zealanders 15 years or older who participated in the 1997 National Nutrition Survey to determine differences by sex and age. Women had lower proportions of EPA and docosapentaenoic acid in phospholipid, by 0.07 (P = 0.004) and 0.10 (P < 0.001) mol%, respectively, and a higher proportion of DHA by 0.16 mol% (P = 0.001) compared with men. Intake of fish fat did not differ between men and women. There was a positive association between age and the proportion of EPA and DHA in phospholipid (P < 0.001). The sex differences in EPA and DHA were similar at all ages. Similar sex and age differences in serum cholesterol ester n-3 long-chain PUFA were found; only age differences were found in serum TAG. Sex and age differences in n-3 long-chain PUFA occur in the general population. Men and women may need to be considered separately when examining the association between disease risk and biomarkers of n-3 fatty acids.

Red cell folate and predicted neural tube defect rate in three Asian cities.

BACKGROUND: Periconceptional folic acid reduces neural tube defect (NTD) risk. Red blood cell folate concentration is inversely associated with NTD risk. In many countries there is a lack of information on NTD rates. Red cell folate status in women of childbearing age may be a surrogate for NTD rates and may be helpful in identifying countries or regions most likely to benefit from improved folate status. OBJECTIVE: To predict NTD rates using red cell folate concentrations in women of childbearing age living in three Asian cities Design: Cross-sectional convenience samples of non-pregnant women living in Beijing (n=220), Kuala Lumpur (n=389), and Jakarta (n=129). RESULTS: Red cell folate concentrations were highest (p<0.001) in women from Jakarta at 872 nmol/L (95% CI; 833, 910) followed by Kuala Lumpur at 674 nmol/L (95% CI: 644, 704) and lowest in Beijing at 563 nmol/L (95% CI: 524, 601). Accordingly, predicted NTD rates were highest in Beijing at 30/10000 (95% CI: 27, 33), followed by Kuala Lumpur at 24/10000 (95% CI: 22, 25), and lowest in Jakarta at 15/10000 (95% CI: 14,15). CONCLUSION: Our red blood cell folate data suggests that of the three cities improving the folate status of women in Beijing would have the greatest impact on NTD rates.

Serum fatty acids as biomarkers of fat intake predict serum cholesterol concentrations in a population-based survey of New Zealand adolescents and adults.

BACKGROUND: The results of randomized controlled trials indicate that the amount and type of dietary fat are important predictors of serum cholesterol concentrations. However, the results of observational studies show weak or no association between dietary fat intake and serum cholesterol. Serum fatty acids are valid biomarkers of fat intake and may improve dietary estimates. OBJECTIVE: The objective was to ascertain whether serum fatty acids are associated with serum cholesterol concentrations in New Zealand adolescents and adults. DESIGN: The current study was a cross-sectional, national, population-based survey of 2793 New Zealanders aged > or =15 y who participated in the 1997 National Nutrition Survey. The fatty acid composition of serum cholesterol esters, phospholipids, and triacylglycerols was measured. RESULTS: A 1-SD increase in myristic acid (14:0) in serum cholesterol ester, phospholipids, and triacylglycerol corresponded with increases in serum cholesterol of 0.19, 0.13, and 0.10 mmol/L, respectively, after adjustment of the regression analysis for sex, age, body mass index, ethnicity, and smoking. The mean difference in cholesterol concentrations between persons in the highest and the lowest quintiles of serum cholesteryl-myristate was 0.48 mmol/L (P for trend < 0.001). A 1-SD increase in the proportion of linoleic acid (18:2n-6) in serum cholesterol ester, phospholipids, and triacylglycerol corresponded with decreases in serum cholesterol of 0.07, 0.07, and 0.05 mmol/L, respectively. The difference in mean serum cholesterol between the highest and lowest quintiles of cholesteryl-linoleate was 0.18 mmol/L (P for trend = 0.019). CONCLUSION: Saturated and polyunsaturated fat intakes, measured by using fatty acid biomarkers, are important predictors of serum cholesterol concentrations in New Zealand.