Last data update: Sep 30, 2024. (Total: 47785 publications since 2009)
Records 1-26 (of 26 Records) |
Query Trace: Qi YP[original query] |
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Folate and vitamin B(12) status and predicted neural tube defects risk among nonpregnant women of reproductive age from the Malawi National Micronutrient Survey, 2015-2016
Qi YP , Crider KS , Williams AM , Tripp K , Mapango C , Rhodes EC , Nyirenda E , Phiri F , Zhang M , Jabbar S , Pfeiffer CM , Pachón H , Zimmerman S , Williams JL . Birth Defects Res 2024 116 (3) e2329 BACKGROUND: Maternal folate and vitamin B(12) deficiency can lead to serious adverse pregnancy outcomes. There are no nationally representative estimates on folate and vitamin B(12) status among women of reproductive age (WRA) in Malawi. OBJECTIVE: We assessed folate and vitamin B(12) status among nonpregnant WRA in Malawi and predicted the risk of folate-sensitive neural tube defects (NTDs) were they to become pregnant. METHODS: Using data from the cross-sectional, nationally representative 2015-2016 Malawi Micronutrient Survey, we calculated the proportion of folate and vitamin B(12) deficiency and insufficiency by demographic characteristics among 778 nonpregnant WRA (15-49 years). We predicted NTD prevalence using red blood cell (RBC) folate distributions and a published Bayesian model of the association between RBC folate and NTD risk. Analyses accounted for complex survey design. RESULTS: Among WRA, 8.5% (95% CI: 6.2, 11.6) and 13.3% (10.0, 17.4) had serum (<7 nmol/L) and RBC folate (<305 nmol/L) deficiency, respectively. The proportion of vitamin B(12) deficiency (<148 pmol/L) and insufficiency (≤221 pmol/L) was 11.8% (8.6, 16.0) and 40.6% (34.1, 47.4), respectively. RBC folate insufficiency (<748 nmol/L, defined as the concentration associated with the threshold for elevated NTD risk: >8 cases per 10,000 births) was widespread: 81.4% (75.0, 86.4). The predicted NTD risk nationally was 24.7 cases per 10,000 live births. RBC folate insufficiency and higher predicted NTD risk were more common among WRA living in urban areas or with higher education. CONCLUSIONS: These findings highlight the importance of nutritional and NTD surveillance in Malawi and the opportunity for improving folate and vitamin B(12) nutrition among Malawian WRA. |
Vitamin B12 supplementation during pregnancy for maternal and child health outcomes
Finkelstein JL , Fothergill A , Venkatramanan S , Layden AJ , Williams JL , Crider KS , Qi YP . Cochrane Database Syst Rev 2024 1 (1) Cd013823 BACKGROUND: Vitamin B(12) deficiency is a major public health problem worldwide, with the highest burden in elderly people, pregnant women, and young children. Due to its role in DNA synthesis and methylation, folate metabolism, and erythropoiesis, vitamin B(12) supplementation during pregnancy may confer longer-term benefits to maternal and child health outcomes. OBJECTIVES: To evaluate the benefits and harms of oral vitamin B(12) supplementation during pregnancy on maternal and child health outcomes. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP) on 2 June 2023, and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials (RCTs), quasi-RCTs, or cluster-RCTs evaluating the effects of oral vitamin B(12) supplementation compared to placebo or no vitamin B(12) supplementation during pregnancy. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Four review authors independently assessed trial eligibility. Two review authors independently extracted data from included studies and conducted checks for accuracy. Three review authors independently assessed the risk of bias of the included studies using the Cochrane RoB 1 tool. We used GRADE to evaluate the certainty of evidence for primary outcomes. MAIN RESULTS: The review included five trials with 984 pregnant women. All trials were conducted in low- and middle-income countries, including India, Bangladesh, South Africa, and Croatia. At enrolment, 26% to 51% of pregnant women had vitamin B(12) deficiency (less than 150 pmol/L), and the prevalence of anaemia (haemoglobin less than 11.0 g/dL) ranged from 30% to 46%. The dosage of vitamin B(12) supplementation varied from 5 μg/day to 250 μg/day, with administration beginning at 8 to 28 weeks' gestation through to delivery or three months' postpartum, and the duration of supplementation ranged from 8 to 16 weeks to 32 to 38 weeks. Three trials, involving 609 pregnant women, contributed data for meta-analyses of the effects of vitamin B(12) supplementation compared to placebo or no vitamin B(12) supplementation. Maternal anaemia: there may be little to no difference for maternal anaemia by intervention group, but the evidence is very uncertain (70.9% versus 65.0%; risk ratio (RR) 1.08, 95% confidence interval (CI) 0.93 to 1.26; 2 trials, 284 women; very low-certainty evidence). Maternal vitamin B(12) status: vitamin B(12) supplementation during pregnancy may reduce the risk of maternal vitamin B(12) deficiency compared to placebo or no vitamin B(12) supplementation, but the evidence is very uncertain (25.9% versus 67.9%; RR 0.38, 95% CI 0.28 to 0.51; 2 trials, 272 women; very low-certainty evidence). Women who received vitamin B(12) supplements during pregnancy may have higher total vitamin B(12) concentrations compared to placebo or no vitamin B(12) supplementation (mean difference (MD) 60.89 pmol/L, 95% CI 40.86 to 80.92; 3 trials, 412 women). However, there was substantial heterogeneity (I(2) = 85%). Adverse pregnancy outcomes: the evidence is uncertain about the effect on adverse pregnancy outcomes, including preterm birth (RR 0.97, 95% CI 0.55 to 1.74; 2 trials, 340 women; low-certainty evidence), and low birthweight (RR 1.50, 95% CI 0.93 to 2.43; 2 trials, 344 women; low-certainty evidence). Two trials reported data on spontaneous abortion (or miscarriage); however, the trials did not report quantitative data for meta-analysis and there was no clear definition of spontaneous abortion in the study reports. No trials evaluated the effects of vitamin B(12) supplementation during pregnancy on neural tube defects. Infant vitamin B(12) status: children born to women who received vitamin B(12) supplementation had higher total vitamin B(12) concentrations compared to placebo or no vitamin B(12) supplementation (MD 71.89 pmol/L, 95% CI 20.23 to 123.54; 2 trials, 144 children). Child cognitive outcomes: three ancillary analyses of one trial reported child cognitive outcomes; however, data were not reported in a format that could be included in quantitative meta-analyses. In one study, maternal vitamin B(12) supplementation did not improve neurodevelopment status (e.g. cognitive, language (receptive and expressive), motor (fine and gross), social-emotional, or adaptive (conceptual, social, practical) domains) in children compared to placebo (9 months, Bayley Scales of Infant and Toddler Development Third Edition (BSID-III); 1 trial; low-certainty evidence) or neurophysiological outcomes (72 months, event-related potential measures; 1 trial; low-certainty evidence), though children born to women who received vitamin B(12) supplementation had improved expressive language domain compared to placebo (30 months, BSID-III; 1 trial; low-certainty evidence). AUTHORS' CONCLUSIONS: Oral vitamin B(12) supplementation during pregnancy may reduce the risk of maternal vitamin B(12) deficiency and may improve maternal vitamin B(12) concentrations during pregnancy or postpartum compared to placebo or no vitamin B(12) supplementation, but the evidence is very uncertain. The effects of vitamin B(12) supplementation on other primary outcomes assessed in this review were not reported, or were not reported in a format for inclusion in quantitative analyses. Vitamin B(12) supplementation during pregnancy may improve maternal and infant vitamin B(12) status, but the potential impact on longer-term clinical and functional maternal and child health outcomes has not yet been established. |
Strengthening capacity of health workers to diagnose birth defects in Ugandan hospitals from 2015 to 2021
Namale-Matovu J , Kusolo R , Serunjogi R , Barlow-Mosha L , Mumpe-Mwanja D , Niombi N , Kalibbala D , Williamson D , Valencia D , Moore CA , Mwambi K , Nelson LJ , Namukanja-Mayambala PM , Williams JL , Mai CT , Qi YP , Musoke P . BMC Med Educ 2023 23 (1) 766 BACKGROUND: Limited diagnostic capabilities, resources and health worker skills have deterred the advancement of birth defects surveillance systems in most low- and middle-income countries (LMICs). Empowering health workers to identify and diagnose major external birth defects (BDs) is crucial to establishing effective hospital-based BD surveillance. Makerere University-Johns Hopkins University (MU-JHU) Research Collaboration BD Surveillance System consists of three diagnostic levels: (1) surveillance midwives, (2) MU-JHU clinical team, and (3) U.S. Centers for Disease Control and Prevention (CDC) birth defects subject matter experts (SMEs) who provide confirmatory diagnosis. The diagnostic concordance of major external BDs by surveillance midwives or MU-JHU clinical team with CDC birth defects SMEs were estimated. METHODS: Study staff went through a series of trainings, including birth defects identification and confirmation, before surveillance activities were implemented. To assess the diagnostic concordance, we analyzed surveillance data from 2015 to 2021 for major external BDs: anencephaly, iniencephaly, encephalocele, spina bifida, craniorachischisis, microcephaly, anophthalmia/microphthalmia, anotia/microtia, cleft palate alone, cleft lip alone, cleft lip with cleft palate, imperforate anus, hypospadias, talipes equinovarus, limb reduction, gastroschisis, and omphalocele. Positive predictive value (PPV) as the proportion of BDs diagnosed by surveillance midwives or MU-JHU clinical team that were confirmed by CDC birth defects SMEs was computed. PPVs between 2015 and 2018 and 2019-2021 were compared to assess the accuracy of case diagnosis over time. RESULTS: Of the 204,332 infants examined during 2015-2021, 870 infants had a BD. Among the 1,245 BDs identified, 1,232 (99.0%) were confirmed by CDC birth defects SMEs. For surveillance midwives, PPV for 7 of 17 BDs was > 80%. For the MU-JHU clinical team, PPV for 13 of 17 BDs was > 80%. Among surveillance midwives, PPV improved significantly from 2015 to 2018 to 2019-2021, for microcephaly (+ 50.0%), cleft lip with cleft palate (+ 17.0%), imperforate anus (+ 30.0%), and talipes equinovarus (+ 10.8%). Improvements in PPV were also observed among MU-JHU clinical team; however, none were significant. CONCLUSION: The diagnostic accuracy of the midwives and clinical team increased, highlighting that BD surveillance, by front-line health care workers (midwives) in LMICs is possible when midwives receive comprehensive training, technical support, funding and continuous professional development. |
Folate and vitamin B12 usual intake and biomarker status by intake source in U.S. adults (19 y): National Health and Nutrition Examination Survey (NHANES) 2007-2018
Zhou Y , Wang A , Yeung LF , Qi YP , Pfeiffer CM , Crider KS . Am J Clin Nutr 2023 118 (1) 241-254 OBJECTIVES: Folate and vitamin B12 are important biomarkers of nutritional status of populations. This study aims to estimate folate and vitamin B12 usual intakes among US adults and examine folate and vitamin B12 biomarker status by intake source. METHODS: We analyzed data for U.S. adults (≥19 y) from National Health and Nutrition Examination Survey (NHANES) 2007-2018 (n=31,128), during which time voluntary corn masa flour fortification was started. Usual intake was estimated using National Cancer Institute (NCI) method. Folate intake included folate from natural foods and folic acid from four sources-enriched cereal grain products (ECGP), corn masa flour (CMF), ready-to-eat cereals (RTE), and folic acid containing supplements (SUP). Vitamin B12 is found in food and supplements. RESULTS: Median natural food folate intake (222 μg dietary folate equivalents (DFE)/d) was below the estimated average requirement (EAR) of 320 μg DFE/d. Proportions of those who consumed folic acid from ECGP/CMF only, ECGP/CMF+RTE, ECGP/CMF+SUP, and ECGP/CMF+RTE+SUP were 50%, 18%, 22%, and 10%, respectively. Median usual folic acid intakes (μg/d) were 236 (interquartile range: 152, 439) overall, and 134, 313, 496, 695 in the ECGP/CMF only, ECGP/CMF+RTE, ECGP/CMF+SUP, ECGP/CMF+RTE+SUP folic acid consumption groups, respectively. Overall, 2.0% (95% CI: 1.7%, 2.3%) of adults, all of whom used folic acid supplements, consumed greater than tolerable upper intake level (UL) of 1000 μg/d folic acid. Median usual vitamin B12 intake (μg/d) was 5.2 for vitamin B12 supplement non-users and 21.8 for users. Consumption of RTE and/or supplements with folic acid was associated with higher serum and RBC folate concentrations. Vitamin B12 supplement users had significantly higher serum vitamin B12 concentrations. CONCLUSIONS: Folic acid fortification plays a critical role in helping U.S. adults meet folate EAR. At current fortification levels, U.S. adults who do not consume supplements do not have usual folic acid intake exceeding the UL. |
Estimating the serum folate concentration that corresponds to the red blood cell folate concentration threshold associated with optimal neural tube defects prevention: A population-based biomarker survey in Southern India
Fothergill A , Crider KS , Rose CE , Bose B , Guetterman HM , Johnson CB , Jabbar S , Zhang M , Pfeiffer CM , Qi YP , Williams JL , Kuriyan R , Bonam W , Finkelstein JL . Am J Clin Nutr 2023 117 (5) 985-997 BACKGROUND: RBC folate concentrations are monitored at the population level, with a recommended threshold for optimal neural tube defect (NTD) prevention. A corresponding threshold for serum folate has not been established. OBJECTIVES: This study aimed to estimate the serum folate insufficiency threshold corresponding to the RBC folate threshold for NTD prevention and examine how this threshold is modified by vitamin B(12) status. METHODS: Participants were women (15-40 y; not pregnant or lactating; n = 977) from a population-based biomarker survey in Southern India. RBC folate and serum folate were measured via microbiologic assay. RBC folate deficiency (<305 nmol/L) and insufficiency (<748 nmol/L), serum vitamin B(12) deficiency (<148 pmol/L) and vitamin B(12) insufficiency (<221 pmol/L), elevated plasma MMA (>0.26 μmol/L), elevated plasma homocysteine (>10.0 μmol/L), and elevated HbA1c (≥6.5%) were evaluated. Bayesian linear models were used to estimate unadjusted and adjusted thresholds. RESULTS: Compared with adequate vitamin B(12) status, the estimated serum folate threshold was higher in participants with serum vitamin B(12) deficiency (72.5 vs. 28.1 nmol/L) or vitamin B(12) insufficiency (48.7 vs. 24.3 nmol/L) and elevated MMA (55.6 vs. 25.9 nmol/L). The threshold was lower in participants with elevated HbA1c (HbA1c ≥6.5% vs. <6.5%; 21.0 vs. 40.5 nmol/L). CONCLUSIONS: The estimated serum folate threshold for optimal NTD prevention was similar to previous reports (24.3 vs. 25.6 nmol/L) among participants with sufficient vitamin B(12) status. However, this threshold was more than 2-fold higher in participants with vitamin B(12) deficiency and substantially higher across all indicators of insufficient vitamin B(12) status (<221 pmol/L, elevated MMA, combined B(12), impaired vitamin B(12) status), and lower in participants with elevated HbA1c. Findings suggest a serum folate threshold for NTD prevention may be possible in some settings; however, it may not be appropriate in populations with high prevalence of vitamin B(12) insufficiency. Am J Clin Nutr 2023;xx:xx-xx. This trial was registered at https://clinicaltrials.gov as NCT04048330. |
A randomized trial of quadruple-fortified salt for anemia and birth defects prevention in southern India: Protocol design and methods
Finkelstein JL , Guetterman HM , Fothergill A , Johnson CB , Qi YP , Jabbar S , Zhang M , Pfeiffer CM , Rose CE , Yeung LF , Williams JL , Krisher JT , Ruth C , Roy Choudhury D , Venkatramanan S , Haas JD , Kuriyan R , Mehta S , Bonam W , Crider KS . Curr Dev Nutr 2023 7 (3) 100052 Background: Women of reproductive age are at an increased risk of anemia and micronutrient deficiencies. Evidence supports the role of periconceptional nutrition in the development of neural tube defects (NTDs) and other pregnancy complications. Vitamin B12 deficiency is a risk factor for NTDs and may modify folate biomarkers that predict NTD risk at the population level. There is an interest in mandatory fortification with vitamin B12 and folic acid for anemia and birth defect prevention. However, there are limited population-representative data needed to inform policy and guidelines. Objectives: This randomized trial will be conducted to evaluate the efficacy of quadruple-fortified salt (QFS; iron, iodine, folic acid, vitamin B12) in 1,000 households in Southern India. Methods: Women 18 to 49 y who are not pregnant or lactating and reside within the catchment area of our community-based research site in Southern India will be screened and invited to participate in the trial. After informed consent, women and their households will be randomized to receive one of the following 4 interventions: 1) double-fortified salt (DFS; iron, iodine), 2) DFS + folic acid (iron, iodine, folic acid), 3) DFS + vitamin B12 (iron, iodine, vitamin B12), or 4) DFS + folic acid and vitamin B12 (QFS; iron, iodine, folic acid, vitamin B12) for 12 mo. Structured interviews will be conducted by trained nurse enumerators to collect sociodemographic, anthropometric, dietary, health, and reproductive history data. Biological samples will be collected at baseline, midpoint, and endpoint. Whole blood will be analyzed for hemoglobin using Coulter Counter. Total vitamin B12 will be measured by chemiluminescence; red blood cell folate and serum folate will be evaluated using the World Health Organization-recommended microbiologic assay. Conclusions: The results of this randomized trial will help to evaluate the efficacy of QFS to prevent anemia and micronutrient deficiencies. Clinical trial registration numbers: NCT03853304 and Clinical Trial Registry of India REF/2019/03/024479. Registration number: NCT03853304 and REF/2019/03/024479. © 2023 The Author(s) |
Comparison of anemia screening methods using paired venous samples in women of reproductive age in Southern India
Fothergill A , Crider KS , Johnson CB , Raj MP , Guetterman HM , Bose B , Rose CE , Qi YP , Williams JL , Kuriyan R , Bonam W , Finkelstein JL . J Nutr 2022 152 (12) 2978-2992 BACKGROUND: Anemia is an important public health problem, and accurate estimates may inform policy and programs. Although hemoglobin assessment of venous blood via automated hematology analyzers (AHA) is recommended, most population-based surveys are based on analysis of capillary blood via portable hemoglobinometers to estimate anemia prevalence. OBJECTIVE: To evaluate screening methods for hemoglobin and anemia assessment using paired venous samples. DESIGN: Participants were women of reproductive age (15-40y) who were not pregnant or lactating. Paired venous whole blood samples (n = 896) were analyzed for hemoglobin (Hb) via portable hemoglobinometer (HemoCue 301) and Coulter Counter AHA. Anemia and severe anemia were defined as Hb <12.0 and <8.0 g/dL, respectively. Bland-Altman methods were used to assess level of agreement for Hb results (mean difference, standard deviation of differences, limits of agreement). Diagnostic accuracy parameters (sensitivity, specificity, positive predictive value, negative predictive value, accuracy) were calculated to evaluate HemoCue performance compared to the AHA reference, overall and by sociodemographic, nutritional, and metabolic characteristics. RESULTS: The estimated anemia prevalence was significantly lower via HemoCue vs. AHA (36.3% vs. 41.6%; p-value <0.0001). The HemoCue had 84.4% accuracy for anemia screening and 98.8% for severe anemia, compared to the AHA reference. The HemoCue had 74.8% sensitivity and 91.2% specificity, compared to AHA. HemoCue sensitivity was higher in WRA with iron deficiency (SF<15.0 g/L 81.6% vs. SF 15.0 g/L: 41.3%), and lower in WRA with metabolic risk factors, including overweight (BMI25.0 kg/m2; 63.9% vs. 78.8%), or elevated CRP (CRP>1.0 mg/L: 67.2% vs. 1.0 mg/L: 82.9%), trunk fat (TF>35%: 62.7% vs. 35%: 80.1), or whole-body fat (WBF >35%: 63.9% vs. 35%: 80.3%). CONCLUSION: Findings suggest that women with anemia may be incorrectly identified as not anemic via portable hemoglobinometer, and the anemia prevalence may be underestimated at the population level. Registration number: NCT04048330. |
Folic acid and the prevention of birth defects: 30 years of opportunity and controversies
Crider KS , Qi YP , Yeung LF , Mai CT , Head Zauche L , Wang A , Daniels K , Williams JL . Annu Rev Nutr 2022 42 423-452 For three decades, the US Public Health Service has recommended that all persons capable of becoming pregnant consume 400 μg/day of folic acid (FA) to prevent neural tube defects (NTDs). The neural tube forms by 28 days after conception. Fortification can be an effective NTD prevention strategy in populations with limited access to folic acid foods and/or supplements. This review describes the status of mandatory FA fortification among countries that fortify (n = 71) and the research describing the impact of those programs on NTD rates (up to 78% reduction), blood folate concentrations [red blood cell folate concentrations increased ∼1.47-fold (95% CI, 1.27, 1.70) following fortification], and other health outcomes. Across settings, high-quality studies such as those with randomized exposures (e.g., randomized controlled trials, Mendelian randomization studies) are needed to elucidate interactions of FA with vitamin B(12) as well as expanded biomarker testing. |
Vitamin B-12 malabsorption and renal function are critical considerations in studies of folate and vitamin B-12 interactions in cognitive performance: NHANES 2011-2014
Samson ME , Yeung LF , Rose CE , Qi YP , Taylor CA , Crider KS . Am J Clin Nutr 2022 116 (1) 74-85 BACKGROUND: Cognitive health is a public health concern among older adults. Dietary supplement (SUP) use is common and concerns have been raised about high folic acid intake among those with vitamin B-12 deficiency and exacerbation of poor cognitive performance (PCP). OBJECTIVES: We evaluated SUP use, usual folic acid intake, and blood folate and vitamin B-12 concentrations in relation to cognitive performance. METHODS: We used NHANES 2011-2014 data on adults aged ≥60 y (n = 2867) and estimated total usual folic acid intake from diet and supplements, vitamin B-12 intake from SUPs, blood folates, vitamin B-12 concentrations, vitamin B-12 insufficiency (≤258 pmol/L), high folate (serum folate ≥59 nmol/L or RBC folate ≥1609 nmol/L), and PCP (<34 on the Digit Symbol Substitution Test). We assessed folate distributions adjusted for multiple variables, including renal function. RESULTS: Compared with persons without PCP, adults with PCP were less likely to use supplements containing folic acid (mean ± SEE: 34.4% ± 2.4%) or vitamin B-12 (mean ± SEE: 47.5% ± 1.6%). Among vitamin B-12-insufficient adults, 18.0% ± 1.6% (mean ± SEE) reported taking a vitamin B-12 supplement. Among participants with high folate and insufficient vitamin B-12 concentrations, 34.3% ± 11.5% (mean ± SEE) reported taking vitamin B-12-containing supplements. Persons with high folate and normal vitamin B-12 concentrations had lower odds of PCP [aOR (adjusted odds ratio): 0.61; 95% CI: 0.45, 0.83] than persons with normal folate and vitamin B-12. Persons with high folate and normal methylmalonic acid (MMA) had lower odds of PCP (OR: 0.56; 95% CI: 0.40, 0.78) than those with normal folate and MMA concentrations. After adjustment for renal function, elevated risk of PCP was attenuated among persons with high folate and MMA. Concurrent high folate and insufficient vitamin B-12 concentrations were not associated with PCP. CONCLUSIONS: Differential associations between vitamin B-12 and MMA highlight the need to consider renal function in studies of high folate and low vitamin B-12 status. Consumption of vitamin B-12 supplements concurrent with low vitamin B-12 status may indicate vitamin B-12 malabsorption. |
Iron status and inflammation in women of reproductive age: A population-based biomarker survey and clinical study
Finkelstein JL , Fothergill A , Guetterman HM , Johnson CB , Bose B , Qi YP , Rose CE , Williams JL , Mehta S , Kuriyan R , Bonam W , Crider KS . Clin Nutr ESPEN 2022 49 483-494 Background: Women of reproductive age (WRA) are at increased risk for anemia and iron deficiency. However, there is limited population-level data in India, which could help inform evidence-based recommendations and policy. Aims: To conduct a population-based biomarker survey of anemia, iron deficiency, and inflammation in WRA in Southern India. Methods: Participants were WRA (15-40 y) who were not pregnant or lactating. Blood samples (n = 979) were collected and analyzed for hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and alpha-1 acid glycoprotein (AGP). Anemia and severe anemia were defined as Hb < 12.0 and < 8.0 g/dL. Serum ferritin was adjusted for inflammation using BRINDA methods. Iron deficiency was defined as SF <15.0 μg/L, iron insufficiency was defined as SF < 20.0 and < 25.0 μg/L, and iron deficiency anemia was defined as Hb < 12.0 g/dL and SF < 15.0 μg/L. Inflammation was defined as CRP > 5.0 mg/L or AGP > 1.0 g/L. Restricted cubic spline regression models were also used to determine if alternative SF thresholds should be used t to classify iron deficiency. Results: A total of 41.5% of WRA had anemia, and 3.0% had severe anemia. Findings from spline analyses suggested a SF cut-off of < 15.0 μg/L, consistent with conventional cut-offs for iron deficiency. 46.3% of WRA had SF < 15.0 μg/L (BRINDA-adjusted: 61.5%), 55.0% had SF < 20.0 μg/L (72.7%), 61.8% had SF < 25.0 μg/L (81.0%), and 30.0% had IDA (34.5%). 17.3% of WRA had CRP > 5.0 mg/L and 22.2% had AGP > 1.0 g/L. The prevalence of ID (rural vs. urban: 49.1% vs. 34.9%; p = 0.0004), iron insufficiency (57.8% vs. 43.8%; p = 0.0005), and IDA (31.8% vs. 22.4%; p = 0.01) were significantly higher in rural areas, although CRP levels were lower and there were no differences in elevated CRP or AGP. Conclusions: The burden of anemia and iron deficiency in this population was substantial, and increased after adjusting for inflammation, suggesting potential to benefit from screening and interventions. Registration number: NCT04048330. © 2022 The Author(s) |
Folic acid supplementation and malaria susceptibility and severity among people taking antifolate antimalarial drugs in endemic areas
Crider KS , Williams JL , Qi YP , Gutman J , Yeung LF , Mai CT , Finkelstein JL , Mehta S , Pons-Duran C , Menéndez C , Moraleda C , Rogers LM , Daniels K , Green P . Cochrane Database Syst Rev 2022 2022 (2) Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To examine the effects of folic acid supplementation, at various doses, on malaria susceptibility (risk of infection) and severity among people living in areas with various degrees of malaria endemicity. We will examine the interaction between folic acid supplements and antifolate antimalarial drugs. Specifically, we will aim to answer the following. Among uninfected people living in malaria endemic areas, who are taking or not taking antifolate antimalarials for malaria prophylaxis, does taking a folic acid-containing supplement increase susceptibility to or severity of malaria infection? Among people with malaria infection who are being treated with antifolate antimalarials, does folic acid supplementation increase the risk of treatment failure?. Copyright © 2022 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. |
Anemia and Vitamin B-12 and Folate Status in Women of Reproductive Age in Southern India: Estimating Population-Based Risk of Neural Tube Defects
Finkelstein JL , Fothergill A , Johnson CB , Guetterman HM , Bose B , Jabbar S , Zhang M , Pfeiffer CM , Qi YP , Rose CE , Williams JL , Bonam W , Crider KS . Curr Dev Nutr 2021 5 (5) nzab069 BACKGROUND: Women of reproductive age (WRA) are a high-risk population for anemia and micronutrient deficiencies. However, there are few representative population-level data from India, which could help inform evidence-based recommendations and policy. OBJECTIVE: To conduct a population-based biomarker survey of anemia and vitamin B-12 and folate status in WRA as part of a periconceptional surveillance program in southern India. METHODS: Participants were WRA (15-40 y) who were not pregnant or lactating. Whole blood (n = 979) was analyzed for hemoglobin via a Coulter counter (Coulter HMX). Plasma, serum, and RBCs were processed and stored at -80°C or less until batch analysis. Vitamin B-12 concentrations were measured via chemiluminescence; RBC and serum folate concentrations were evaluated via microbiological assay. Anemia and severe anemia were defined as hemoglobin <12.0 g/dL and <8.0 g/dL, respectively. Vitamin B-12 deficiency and insufficiency were defined as total vitamin B-12 <148 pmol/L and <221 pmol/L, respectively. Folate deficiency and insufficiency were defined as RBC folate <305 nmol/L and <748 nmol/L. A previously developed Bayesian model was used to predict neural tube defect (NTD) prevalence per 10,000 births. RESULTS: A total of 41.5% of WRA had anemia and 3.0% had severe anemia. A total of 48.3% of WRA had vitamin B-12 deficiency and 74.3% had vitamin B-12 insufficiency. The prevalence of RBC folate deficiency was 7.6%, and 79.3% of WRA had RBC folate <748 nmol/L, the threshold for optimal NTD prevention. Predicted NTD prevalence per 10,000 births based on RBC folate concentrations was 20.6 (95% uncertainty interval: 16.5-25.5). CONCLUSIONS: The substantial burden of anemia, vitamin B-12 deficiency, and RBC folate insufficiency in WRA in this setting suggests an opportunity for anemia and birth defects prevention. Findings will directly inform the development of a randomized trial for anemia and birth defects prevention in southern India.This study was registered at clinicaltrials.gov as NCT04048330. |
Impact of Voluntary Folic Acid Fortification of Corn Masa Flour on RBC Folate Concentrations in the U.S. (NHANES 2011-2018)
Wang A , Rose CE , Qi YP , Williams JL , Pfeiffer CM , Crider KS . Nutrients 2021 13 (4) Surveillance data have highlighted continued disparities in neural tube defects (NTDs) by race-ethnicity in the United States. Starting in 2016, the Food and Drug Administration (FDA) authorized voluntary folic acid fortification of corn masa flour to reduce the risk of neural tube defects (NTDs) among infants of Hispanic women of reproductive age. To assess the impact of voluntary corn masa fortification, cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 for Hispanic women of reproductive age with available red blood cell (RBC) folate concentrations were analyzed, with additional analyses conducted among Hispanic women whose sole source of folic acid intake was fortified foods (enriched cereal grain products (ECGP) only), excluding ready-to-eat cereals and supplements. RBC folate concentration (adjusted geometric mean) among Hispanic women of reproductive age did not differ between 2011-2016 and 2017-2018, though RBC folate concentration increased significantly among lesser acculturated Hispanic women consuming ECGP only. Concentrations of RBC folate for those born outside the U.S and residing in the U.S <15 years increased from 894 nmol/L (95% CI: 844-946) in 2011-2016 to 1018 nmol/L (95% CI: 982-1162; p < 0.001) in 2017-2018. Primarily Spanish-speaking Hispanic women of reproductive age who only consumed ECGP saw an increase from 941 nmol/L (95% CI: 895-990) in 2011-2016 to 1034 nmol/L (95% CI: 966-1107; p = 0.03) in 2017-2018. By subpopulation, we observed no significant changes in the proportion at risk of NTDs (<748 nmol/L) and no changes in the model-based estimated NTD rates following voluntary corn masa fortification. This analysis suggests that there is a remaining risk among Hispanics for folate sensitive NTDs, though continued monitoring of folate status in future NHANES data cycles will help inform the long-term efficacy of voluntary fortification of corn masa flour. |
Periconceptional surveillance for prevention of anaemia and birth defects in Southern India: protocol for a biomarker survey in women of reproductive age
Finkelstein JL , Fothergill A , Johnson CB , Guetterman HM , Bose B , Jabbar S , Zhang M , Pfeiffer CM , Qi YP , Rose CE , Krisher JT , Ruth CJ , Mehta R , Williams JL , Bonam W , Crider KS . BMJ Open 2020 10 (10) e038305 INTRODUCTION: Women of reproductive age (WRA) are a high-risk population for anaemia and micronutrient deficiencies. Evidence supports the role of periconceptional nutrition in the development of adverse pregnancy complications. However, in India, there are limited population-based data to guide evidence-based recommendations and priority setting. The objective of this study is to conduct a population-based biomarker survey of anaemia and vitamin B(12) and folate status in WRA as part of a periconceptional surveillance programme in Southern India. METHODS: WRA (15-40 years) who are not pregnant or lactating and reside within 50 km(2) of our community research site in Southern India will be screened and invited to participate in the biomarker survey at our research facility at Arogyavaram Medical Centre. After informed consent/assent, structured interviews will be conducted by trained nurse enumerators to collect sociodemographic, dietary, anthropometry, health and reproductive history data. Venous blood samples will be collected at enrolment; whole blood will be analysed for haemoglobin. Plasma, serum and red blood cells (RBCs) will be processed and stored <-80°C until batch analysis. Vitamin B(12) concentrations will be measured via chemiluminescence, and RBC and serum folate concentrations will be evaluated using the World Health Organisation (WHO)-recommended microbiological assay at our laboratory in Bangalore. A WHO surveillance system will also be established to determine the baseline prevalence of birth defects in this setting. ETHICS AND DISSEMINATION: This study has obtained clearance from the Health Ministry Screening Committee of the Indian Council of Medical Research. The study protocol was reviewed and approved by the Institutional Review Board at Cornell University and the Institutional Ethics Committees at Arogyavaram Medical Centre and St. John's Research Institute. Findings from this biomarker survey will establish the burden of anaemia and micronutrient deficiencies in WRA and directly inform a randomised trial for anaemia and birth defects prevention in Southern India. The results of this study will be disseminated at international research conferences and as published articles in peer-reviewed journals. TRIAL REGISTRATION NUMBERS: Clinical trials registration number NCT04048330, NCT03853304 and Clinical Trials Registry of India (CTRI) registration number REF/2019/03/024479. |
Demographic, physiologic, and lifestyle characteristics observed with serum total folate differ among folate forms: Cross-sectional data from fasting samples in the NHANES 2011-2016
Fazili Z , Sternberg MR , Potischman N , Wang CY , Storandt RJ , Yeung L , Yamini S , Gahche JJ , Juan W , Qi YP , Paladugula N , Gabey G , Pfeiffer CM . J Nutr 2019 150 (4) 851-860 BACKGROUND: Serum folate forms were measured in the US population during recent NHANES to assess folate status. OBJECTIVE: We describe post-folic acid-fortification concentrations of serum folate forms in the fasting US population >/=1 y from the NHANES 2011-2016. METHODS: We measured 5 biologically active folates and 1 oxidation product (MeFox) of 5-methyltetrahydrofolate (5-methyl-THF). We calculated geometric means of 5-methyl-THF, unmetabolized folic acid (UMFA), nonmethyl folate (sum of tetrahydrofolate, 5-formyltetrahydrofolate, and 5,10-methenyltetrahydrofolate), total folate (sum of above biomarkers), and MeFox by demographic, physiologic, and lifestyle variables; estimated the magnitude of variables on biomarker concentrations after covariate adjustment; and determined the prevalence of UMFA >2 nmol/L. RESULTS: After demographic adjustment, age, sex, and race-Hispanic origin were significantly associated with most folate forms. MeFox increased with age, while 5-methyl-THF, UMFA, and nonmethyl folate displayed U-shaped age patterns. Compared with non-Hispanic whites, non-Hispanic blacks had 23% lower predicted 5-methyl-THF but comparable UMFA; non-Hispanic Asians had comparable 5-methyl-THF but 28% lower UMFA; Hispanics, non-Hispanic Asians, and non-Hispanic blacks had approximately 20% lower MeFox. After additional physiologic and lifestyle adjustment, predicted UMFA and MeFox concentrations were 43% and 112% higher, respectively, in adults with chronic kidney disease and 17% and 15% lower, respectively, in adults consuming daily 1-<2 alcoholic beverages; 5-methyl-THF concentrations were 20% lower in adult smokers. The prevalence of UMFA >2 nmol/L was highest in persons aged >/=70 y (9.01%) and lowest in those aged 12-19 y (1.14%). During 2011-2014, the prevalence was 10.6% in users and 2.22% in nonusers of folic acid-containing supplements. CONCLUSIONS: In fasting persons >/=1 y, the demographic, physiologic, and lifestyle characteristics observed with serum total folate differed among folate forms, suggesting biological and/or genetic influences on folate metabolism. High UMFA was mostly observed in supplement users and older persons. |
Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation
Chen MY , Rose CE , Qi YP , Williams JL , Yeung LF , Berry RJ , Hao L , Cannon MJ , Crider KS . Am J Clin Nutr 2019 109 (5) 1452-1461 BACKGROUND: For women of reproductive age, a population-level red blood cell (RBC) folate concentration below the threshold 906 nmol/L or 400 ng/mL indicates folate insufficiency and suboptimal neural tube defect (NTD) prevention. A corresponding population plasma/serum folate concentration threshold for optimal NTD prevention has not been established. OBJECTIVE: The aim of this study was to examine the association between plasma and RBC folate concentrations and estimated a population plasma folate insufficiency threshold (pf-IT) corresponding to the RBC folate insufficiency threshold (RBCf-IT) of 906 nmol/L. METHODS: We analyzed data on women of reproductive age (n = 1673) who participated in a population-based, randomized folic acid supplementation trial in northern China. Of these women, 565 women with anemia and/or vitamin B-12 deficiency were ineligible for folic acid intervention (nonintervention group); the other 1108 received folic acid supplementation for 6 mo (intervention group). We developed a Bayesian linear model to estimate the pf-IT corresponding to RBCf-IT by time from supplementation initiation, folic acid dosage, methyltetrahydrofolate reductase (MTHFR) genotype, body mass index (BMI), vitamin B-12 status, or anemia status. RESULTS: Using plasma and RBC folate concentrations of the intervention group, the estimated median pf-IT was 25.5 nmol/L (95% credible interval: 24.6, 26.4). The median pf-ITs were similar between the baseline and postsupplementation samples (25.7 compared with 25.2 nmol/L) but differed moderately (+/-3-4 nmol/L) by MTHFR genotype and BMI. Using the full population-based baseline sample (intervention and nonintervention), the median pf-IT was higher for women with vitamin B-12 deficiency (34.6 nmol/L) and marginal deficiency (29.8 nmol/L) compared with the sufficient group (25.6 nmol/L). CONCLUSIONS: The relation between RBC and plasma folate concentrations was modified by BMI and genotype and substantially by low plasma vitamin B-12. This suggests that the threshold of 25.5 nmol/L for optimal NTD prevention may be appropriate in populations with similar characteristics, but it should not be used in vitamin B-12 insufficient populations. This trial was registered at clinicaltrials.gov as NCT00207558. |
Systematic review and Bayesian meta-analysis of the dose-response relationship between folic acid intake and changes in blood folate concentrations
Crider KS , Devine O , Qi YP , Yeung LF , Sekkarie A , Zaganjor I , Wong E , Rose CE , Berry RJ . Nutrients 2019 11 (1) The threshold for population-level optimal red blood cell (RBC) folate concentration among women of reproductive age for the prevention of neural tube defects has been estimated at 906 nmol/L; however, the dose-response relationship between folic acid intake and blood folate concentrations is uncharacterized. To estimate the magnitude of blood folate concentration increase in response to specific dosages of folic acid under steady-state conditions (as could be achieved with food fortification), a systematic review of the literature and meta-analysis was conducted. Of the 14,002 records we identified, 533 were selected for full-text review, and data were extracted from 108 articles. The steady-state concentrations (homeostasis) of both serum/plasma and RBC folate concentrations were estimated using a Bayesian meta-analytic approach and one-compartment physiologically-based pharmacokinetic models. RBC folate concentrations increased 1.78 fold (95% credible interval (CI): 1.66, 1.93) from baseline to steady-state at 375(-)570 microg folic acid/day, and it took a median of 36 weeks of folic acid intake (95% CI: 27, 52) to achieve steady-state RBC folate concentrations. Based on regression analysis, we estimate that serum/plasma folate concentrations increased 11.6% (95% CI: 8.4, 14.9) for every 100 microg/day folic acid intake. These results will help programs plan and monitor folic acid fortification programs. |
Development and Utility of a Birth Defects Surveillance Toolkit
Flores AL , Turay K , Valencia D , Hillard CL , Sekkarie A , Zaganjor I , Williams J , Qi YP , Cordero AM , Mulinare J , Botto LD , Peña-Rosas JP , Groisman B , Mastroiacovo P . J Glob Health Perspect 2018 0 According to the World Health Organization (WHO), an estimated 303,000 neonates die within their first month of age every year globally as a result of a birth defect. Neural tube defects, serious birth defects of the brain and spine, are among the most common and severe of these birth defects. Since some low- and middle-income countries lack comprehensive, accurate data documenting the burden of these defects, providing technical assistance to help build birth defects surveillance programs can accelerate the collection of data needed to demonstrate this burden and advance prevention initiatives. We developed a birth defects surveillance toolkit, a technical assistance tool for country staff to help them implement birth defects surveillance. An evaluation of the toolkit with partners in Africa was conducted to assess perceptions of the usefulness, effectiveness, and policy impact of the surveillance toolkit and surveillance-related technical assistance provided to countries thus far. Overall, respondents provided very positive feedback about the toolkit components. Recommendations for improvement included customization to country contexts, such as photos reflective of African babies; surveillance examples from other countries; and consistent use of terms. |
Modeling the impact of folic acid fortification and supplementation on red blood cell folate concentrations and predicted neural tube defect risk in the United States: have we reached optimal prevention
Crider KS , Qi YP , Devine O , Tinker SC , Berry RJ . Am J Clin Nutr 2018 107 (6) 1027-1034 Background: The US CDC and the Institute of Medicine recommend that women capable of becoming pregnant consume >/=400 microg synthetic folic acid/d to prevent neural tube defects (NTDs). The United States has 3 sources of folic acid: fortified enriched cereal grain products (ECGPs), fortified ready-to-eat (RTE) cereals, and dietary supplements. Objective: Our objectives were as follows: 1) to estimate the usual daily folic acid intake and distributions of red blood cell (RBC) folate concentrations among women consuming folic acid from different sources; 2) to assess the usual daily total folic acid intake associated with optimal RBC folate concentrations for NTD prevention; 3) to predict NTD prevalence; and 4) to estimate the number of preventable folate-sensitive NTDs. Design: NHANES data (2007-2012) for nonpregnant women of reproductive age (12-49 y) were used to estimate usual daily intakes of synthetic folic acid and natural food folate. We applied existing models of the relation between RBC folate concentrations and NTD risk to predict NTD prevalence. Results: Based on the distribution of overall RBC folate concentrations (4783 women), the predicted NTD prevalence was 7.3/10,000 live births [95% uncertainty interval (UI): 5.5-9.4/10,000 live births]. Women consuming folic acid from ECGPs as their only source had lower usual daily total folic acid intakes (median: 115 microg/d; IQR: 79-156 microg/d), lower RBC folate concentrations (median: 881 nmol/L; IQR: 704-1108 nmol/L), and higher predicted NTD prevalence (8.5/10,000 live births; 95% UI: 6.4-10.8/10,000 live births) compared with women consuming additional folic acid from diet or supplements. If women who currently consume folic acid from ECGPs only (48% of women) consumed additional folic acid sources, 345 (95% UI: 0-821) to 701 (95% UI: 242-1189) additional NTDs/y could be prevented. Conclusions: This analysis supports current recommendations and does not indicate any need for higher intakes of folic acid to achieve optimal NTD prevention. Ensuring 400 microg/d intake of folic acid prior to pregnancy has the potential to increase the number of babies born without an NTD. |
U.S. women of childbearing age who are at possible increased risk of a neural tube defect-affected pregnancy due to suboptimal red blood cell folate concentrations, National Health and Nutrition Examination Survey 2007 to 2012
Tinker SC , Hamner HC , Qi YP , Crider KS . Birth Defects Res A Clin Mol Teratol 2015 103 (6) 517-26 BACKGROUND: Red blood cell (RBC) folate concentrations are a potential biomarker of folate-sensitive neural tube defect (NTD) risk in the population. The purpose of this analysis was to describe women in the U.S. population with RBC folate concentrations below those associated with optimal NTD prevention. METHODS: We used data from the 2007 to 2012 National Health and Nutrition Examination Survey (NHANES) to assess the RBC folate status of U.S. women of childbearing age relative to risk categories for NTD risk based on RBC folate concentrations. We defined suboptimal RBC folate concentrations as those associated with a prevalence of ≥9 NTDs per 10,000 live births. RESULTS: Among nonpregnant women age 12 to 49 years, 22.8% (95% Confidence Interval: 21.1, 24.6) had suboptimal RBC folate concentrations. Women had greater odds of having a suboptimal RBC folate concentration if they did not use dietary supplements containing folic acid; had mandatorily fortified enriched cereal grain products as their only source of folic acid; were non-Hispanic black or Hispanic; or were current smokers. CONCLUSION: Based on RBC folate concentrations, we would predict that the majority of U.S. women of reproductive age are not at increased risk for folate sensitive NTDs in the presence of mandatory folic acid fortification. Prevention policies and programs can be aimed at population subgroups identified as having higher predicted risk for folate-sensitive NTDs based on RBC folate concentrations. |
Assessing the association between natural food folate intake and blood folate concentrations: a systematic review and Bayesian meta-analysis of trials and observational studies
Marchetta CM , Devine OJ , Crider KS , Tsang BL , Cordero AM , Qi YP , Guo J , Berry RJ , Rosenthal J , Mulinare J , Mersereau P , Hamner HC . Nutrients 2015 7 (4) 2663-86 Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992-3 2014) with both natural food folate intake alone and blood folate concentration among females aged 12-49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA) included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI): 4%, 9%) increase in red blood cell (RBC) folate concentration and a 7% (95% CrI: 1%, 12%) increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥450 mug dietary folate equivalents (DFE)/day could achieve the lower bound of an RBC folate concentration (~1050 nmol/L) associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births. |
Assessing the association between the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism and blood folate concentrations: a systematic review and meta-analysis of trials and observational studies.
Tsang BL , Devine OJ , Cordero AM , Marchetta CM , Mulinare J , Mersereau P , Guo J , Qi YP , Berry RJ , Rosenthal J , Crider KS , Hamner HC . Am J Clin Nutr 2015 101 (6) 1286-94 BACKGROUND: The methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism is a risk factor for neural tube defects. The T allele produces an enzyme with reduced folate-processing capacity, which has been associated with lower blood folate concentrations. OBJECTIVE: We assessed the association between MTHFR C677T genotypes and blood folate concentrations among healthy women aged 12-49 y. DESIGN: We conducted a systematic review of the literature published from January 1992 to March 2014 to identify trials and observational studies that reported serum, plasma, or red blood cell (RBC) folate concentrations and MTHFR C677T genotype. We conducted a meta-analysis for estimates of percentage differences in blood folate concentrations between genotypes. RESULTS: Forty studies met the inclusion criteria. Of the 6 studies that used the microbiologic assay (MA) to measure serum or plasma (S/P) and RBC folate concentrations, the percentage difference between genotypes showed a clear pattern of CC > CT > TT. The percentage difference was greatest for CC > TT [S/P: 13%; 95% credible interval (CrI): 7%, 18%; RBC: 16%; 95% CrI: 12%, 20%] followed by CC > CT (S/P: 7%; 95% CrI: 1%, 12%; RBC: 8%; 95% CrI: 4%, 12%) and CT > TT (S/P: 6%; 95% CrI: 1%, 11%; RBC: 9%; 95% CrI: 5%, 13%). S/P folate concentrations measured by using protein-binding assays (PBAs) also showed this pattern but to a greater extent (e.g., CC > TT: 20%; 95% CrI: 17%, 22%). In contrast, RBC folate concentrations measured by using PBAs did not show the same pattern and are presented in the Supplemental Material only. CONCLUSIONS: Meta-analysis results (limited to the MA, the recommended population assessment method) indicated a consistent percentage difference in S/P and RBC folate concentrations across MTHFR C677T genotypes. Lower blood folate concentrations associated with this polymorphism could have implications for a population-level risk of neural tube defects. |
The prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis did not increase among older U.S. adults after mandatory folic acid fortification
Qi YP , Do AN , Hamner HC , Pfeiffer CM , Berry RJ . J Nutr 2014 144 (2) 170-6 Whether folic acid fortification and supplementation at the population level have led to a higher prevalence of vitamin B-12 deficiency in the absence of anemia remains to be examined among a nationally representative sample of older U.S. adults. We assessed the prevalence of low vitamin B-12 status in the absence of anemia or macrocytosis before and after fortification among adults aged >50 y using cross-sectional data from the NHANES 1991-1994 (prefortification) and 2001-2006 (postfortification). We compared the prefortification and postfortification prevalence of multiple outcomes, including serum vitamin B-12 deficiency (<148 pmol/L) and marginal deficiency (148-258 pmol/L) with and without anemia (hemoglobin <130 g/L for men, <120 g/L for women) and with and without macrocytosis (mean cell volume >100 fL) using multinomial logistic regression, adjusting for age, sex, ethnicity, body mass index, C-reactive protein, and vitamin B-12 supplement use. Prefortification and postfortification serum vitamin B-12 deficiency without anemia [4.0 vs. 3.9%; adjusted prevalence ratio (aPR) (95% CI): 0.98 (0.67, 1.44)] or without macrocytosis [4.2 vs. 4.1%; aPR (95% CI): 0.96 (0.65, 1.43)] remained unchanged. Marginal deficiency without anemia [25.1 vs. 20.7%; aPR (95% CI): 0.82 (0.72, 0.95)] or without macrocytosis [25.9 vs. 21.3%; aPR (95% CI): 0.82 (0.72, 0.94)] were both significantly lower after fortification. After fortification, higher folic acid intake was associated with a lower prevalence of low serum B-12 status in the absence of anemia or macrocytosis. Results suggest that the prevalence of low serum B-12 status in the absence of anemia or macrocytosis among older U.S. adults did not increase after fortification. Thus, at the population level, we found no evidence to support concerns that folic acid adversely affected the clinical presentation of vitamin B-12 deficiency among older adults. |
Prenatal folic acid and risk of asthma in children: a systematic review and meta-analysis
Crider KS , Cordero AM , Qi YP , Mulinare J , Dowling NF , Berry RJ . Am J Clin Nutr 2013 98 (5) 1272-81 BACKGROUND: Childhood asthma has become a critical public health problem because of its high morbidity and increasing prevalence. The impact of nutrition and other exposures during pregnancy on long-term health and development of children has been of increasing interest. OBJECTIVE: We performed a systematic review and meta-analysis of the association of folate and folic acid intake during pregnancy and risk of asthma and other allergic outcomes in children. DESIGN: We performed a systematic search of 8 electronic databases for articles that examined the association between prenatal folate or folic acid exposure and risk of asthma and other allergic outcomes (eg, allergy, eczema, and atopic dermatitis) in childhood. We performed a meta-analysis by using a random-effects model to derive a summary risk estimate of studies with similar exposure timing, exposure assessment, and outcomes. RESULTS: Our meta-analysis provided no evidence of an association between maternal folic acid supplement use (compared with no use) in the prepregnancy period through the first trimester and asthma in childhood (summary risk estimate: 1.01; 95% CI: 0.78, 1.30). Because of substantial heterogeneity in exposures and outcomes, it was not possible to generate summary measures for other folate indicators (eg, blood folate concentrations) and asthma or allergy-related outcomes; however, the preponderance of primary risk estimates was not elevated. CONCLUSIONS: Our findings do not support an association between periconceptional folic acid supplementation and increased risk of asthma in children. However, because of the limited number and types of studies in the literature, additional research is needed. |
Near-elimination of folate-deficiency anemia by mandatory folic acid fortification in older US adults: reasons for geographic and racial differences in stroke study 2003-2007
Odewole OA , Williamson RS , Zakai NA , Berry RJ , Judd SE , Qi YP , Adedinsewo DA , Oakley GP Jr . Am J Clin Nutr 2013 98 (4) 1042-7 BACKGROUND: The United States implemented mandatory folic acid fortification of enriched cereal grains in 1998. Although several studies have documented the resulting decrease in anemia and folate deficiency, to our knowledge, no one has determined the prevalence of folate-deficiency anemia after fortification. OBJECTIVE: We determined the prevalence of folate deficiency and folate-deficiency anemia within a sample of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. DESIGN: The REGARDS cohort is a prospective cohort of 30,239 black and white participants living in the contiguous United States. We measured serum folate concentrations in a random sample of 1546 REGARDS participants aged ≥50 y with baseline hemoglobin and red blood cell mean corpuscular volume measurements. Folate deficiency was defined as a serum folate concentration <6.6 nmol/L (<3.0 ng/mL), and anemia was defined as a hemoglobin concentration <13 g/dL in men and <12 g/dL in nonpregnant women (WHO criteria). Folate-deficiency anemia was defined as the presence of both folate deficiency and anemia. RESULTS: The mean hemoglobin concentration was 13.6 g/dL, and 15.9% of subjects had anemia. The median serum folate concentration was 34.2 nmol/L (15.1 ng/mL), and only 2 of 1546 participants 0.1%) were folate deficient. Both subjects were African American women with markedly elevated C-reactive protein concentrations, macrocytosis, and normal serum cobalamin concentrations; only one subject was anemic. Overall, the prevalence of folate-deficiency anemia was <0.1% (1 of 1546 subjects). CONCLUSION: Our data suggest that, after mandatory folic acid fortification, the prevalence of folate-deficiency anemia is nearly nonexistent in a community-dwelling population in the United States. |
Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity
Chandler AL , Hobbs CA , Mosley BS , Berry RJ , Canfield MA , Qi YP , Siega-Riz AM , Shaw GM . Birth Defects Res A Clin Mol Teratol 2012 94 (11) 864-74 BACKGROUND: Maternal nutritional status has been evaluated to clarify its role in development of neural tube defects (NTDs). Maternal folate intake during pregnancy has been closely evaluated for its association with NTDs. The study objective was to examine associations between NTDs and other dietary periconceptional micronutrient intake, particularly nutrients involved in one-carbon metabolism or antioxidant activity. METHODS: Using data from the National Birth Defects Prevention Study, 1997-2005, logistic regression models were used to estimate the relative risk of NTDs based on maternal micronutrient intake. RESULTS: Results were stratified according to folic acid supplement use, race/ethnicity, and maternal body mass index. Analyses included 954 cases (300 with anencephaly, 654 with spina bifida) and 6268 controls. Higher intakes of folate, thiamin, betaine, iron, and vitamin A were associated with decreased risk of anencephaly among some ethnic and clinical groups. In some groups, higher intakes of thiamin, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, and retinol were associated with decreased risk of spina bifida. CONCLUSION: In addition to folic acid, other micronutrients, including thiamin, betaine, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, iron, retinol, and vitamin A, may decrease the risk of NTD occurrence. (Birth Defects Research (Part A) 2012. (c) 2012 Wiley Periodicals, Inc.) |
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