Assessment Of Folate Status Research Articles

Prevalence, risk factors, and treatment of anemia in hospitalized older patients across geriatric and nephrological settings in Italy

Anemia is a common but often underdiagnosed and undertreated geriatric syndrome in hospitalized older patients. In this retrospective multicenter study, we aimed at characterizing the prevalence, risk factors, diagnostic and treatment approach to anemia in older patients admitted to acute care hospitals, focusing on differences between nephrology and geriatrics units. Prevalence and risk factors for anemia, diagnostic inertia (lack of iron, vitamin B12, and folate status assessment), replacement inertia (omitted treatment with iron, vitamin B12 or folic acid), and erythropoiesis-stimulating agents (ESA) inertia were explored. 1963 patients aged 82.7 (6.8) years were included in the study; 66.7% of the study population had anemia; among anemic patients, diagnostic inertia and replacement inertia were common with rates of 22–31% and 50–87%, respectively; omitted treatment with ESA affected 67.2% of patients and was more prevalent in geriatric units. In most cases, patients with ESA inertia were not routinely screened for iron tests. COPD, cancer, eGFR 45–60 ml/min were associated with increased tendency to ESA inertia. In conclusion, anemia had a high prevalence in older patients discharged from acute care units, but it is often underdiagnosed and undertreated.

The Continued Need for the Routine Assessment of Folate Status.

The Choosing Wisely initiative recommended cessation of folate measurement, suggesting folate supplementation in macrocytic anemia. This study reviewed the need for continued blood folate testing at a large SafetyNet county teaching hospital. Red blood cell (RBC) folate, vitamin B12, iron, ferritin, and hemoglobin results were obtained for utilization review. Of the 593 RBC folate results, 69 (11.7%) were deficient and 30 (5%) had high values. Collectively, 369 (73.9%) had normal vitamin B12 levels, 342 (70%) had low hemoglobin, 184 (62.5) had normal and 57 (19.4%) had low ferritin, 122 (38.2%) had normal and 188 (59%) had low iron levels. Atotal of 41 (12%) had normal folate, low ferritin, low hemoglobin, and low iron, suggestive of iron deficiency anemia. There were 11 patients who exhibited low folate, low or normal ferritin, low hemoglobin, and low iron levels, suggesting combined folate and iron deficiency anemias. This study highlights the need for institutions to assess the applicability of national recommendations to their local population.

Assessment of folate status among women of childbearing age from 2000 to 2020

Objective: To analyze the folate status among women of childbearing age worldwide from 2000 to 2020, and explore the impact of socioeconomic factors on folate status, so as to provide support for the formulation of relevant supplementary policies in China in the future. Methods: The "folate" "folic acid" "deficiency" "status" "women" "childbearing" and "reproductive" were used as Chinese and English keywords to systematically search CNKI and PubMed database. Global Health Data Exchange database (GDHx), Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia datasets (BRINDA) and Ground Work publications were systematically searched with "micronutrients" and "nutrition" as keywords. The retrieval time was from January 1, 2000 to August 31, 2020, and the language was restricted to English and Chinese. After title, abstract and full-text screening, a total of 45 literatures were included. The folate status of women of childbearing age in the eligible literature was analyzed, and the income and folate status were tested by Kruskal Wallis H test and Nemenyi test. Results: The M (Q1, Q3) of serum folate deficiency rate and erythrocyte folate insufficiency rate in women of childbearing age were 15.0% (3.5%, 37.0%) and 49.0% (22.0%, 83.0%). There were great differences in serum folate status and serum folate deficiency rate among women of childbearing age in different income countries. The serum folate deficiency rate of women of childbearing age in low-income countries was significantly higher than that in middle and high-income countries. Conclusion: The folate status of women of childbearing age in most countries has not reached the ideal state from 2000 to 2020. More studies on folate supplementation programs should be carried out.

Sociodemographic and clinical determinants of folate deficiency among sickle cell anemia patients in Kano, North Western Nigeria

Context Folate deficiency is common among sickle cell anemia (SCA) patients and could be influenced by factors such as clinical and social conditions. Sociodemographic and clinical determinants of folate deficiency have not been previously investigated among SCA patients in this environment. Aims The aim was to determine the sociodemographic and clinical factors associated with folate deficiency in SCA patients accessing care at Aminu Kano Teaching Hospital, Kano. Settings and design This was a cross-sectional study involving 110 SCA participants at steady state. Patients and methods Sociodemographic and clinical data of the participants were collated, while their folate status was determined using Roche Elecsys 2010. Statistical analysis Data were analyzed with SPSS version 21.0 and level of significance was set at P less than or equal to 0.05. Results The mean age of the participants was 14.9±7.1 years and the majority of them were men (58, 52.7%), students (96, 87.3%), and jaundiced (66, 60.0%). Age, sex, occupation of the participants, and mother’s level of education were significantly associated with folate deficiency (P Conclusion Sociodemographic and clinical characteristics are important determinants of folate deficiency in SCA. We therefore recommend periodic assessment of folate status as part of the standard care to SCA patients to prevent complications of folate deficiency.

Point-of-Care Assessment of Folate Status in Women of Reproductive Age Using a Fluorescence Lateral Flow Assay.

Folate is an essential vitamin to the development of a fetus in early pregnancy. Maternal folate supplementation around the time of conception has been shown to decrease the risk of neural tube defects (NTDs), a class of serious birth defects. The closure of the neural tube before the 28th day after conception necessitates that the folate intake must take place before most women know that they are pregnant. Therefore, screening women of reproductive age for folate status would allow for an improved understanding of the need for supplementation in women who could become pregnant as well as the effectiveness of current supplementation and fortification recommendations. Current folate assessment is limited to labbased assays which require expensive equipment, trained personnel, and are time-intensive. Our point-of-care diagnostic test quantifies levels of folate in human serum with the use of a lateral flow assay and a portable imaging device. We have designed an assay which uses fluorescent particles, folate binding protein, and antibodies to measure serum folate. This test could be used in resource-limited settings, where access to laboratory infrastructure is limited and where knowledge of folate status in women of reproductive age is lacking. By increasing our understanding of folate status around the world, we can improve implementation of folic acid supplementation and fortification and therefore reduce the risk of NTDs.

Improving maternal folate status to prevent infant neural tube defects: working group conclusions and a framework for action.

As infectious disease control programs achieve increasing success, further reductions in child mortality in low- and middle-income countries (LMICs) will require focused prevention strategies for birth defects and other noninfectious diseases. Neural tube defects (NTDs) can cause early death or lifelong disability. Preventing NTDs provides a feasible, significant opportunity to decrease the toll of birth defects and contribute to further reducing child mortality globally. The Micronutrient Forum convened a technical consultation on Folate Status in Women and Neural Tube Defects Prevention to develop a roadmap to inform and prioritize investments in NTD prevention in LMICs; help guide implementation efforts in terms of the feasibility of interventions and the potential for acceleration; and identify research and knowledge gaps. Here, we describe the impetus for and approach to the consultation and present the conclusions and a framework for developing a roadmap for action to accelerate NTD prevention in LMICs. The framework (1) provides options for action on folate status assessment; (2) outlines a way forward to develop and implement a time-bound global action plan for NTD prevention; and (3) identifies common impediments to NTD prevention, broad strategies to overcome or minimize these impediments, and basic building blocks necessary to accelerate action.

Folic acid intake and folate status and colorectal cancer risk: A systematic review and meta-analysis

To evaluate the controversies among the studies assessing the association between folic acid intake or folate status and colorectal cancer risk. PubMed, Cochrane library and references of related articles were searched from January 2000 to September 2016. Studies on folic acid intake or folate status and colorectal cancer or adenoma risk were included. Full text review was conducted for potentially eligible studies. Quality assessment was performed. Random-effects meta-analysis was used to estimate risk ratio and 95% Confidence Intervals. Analysis was conducted by Comprehensive Meta-Analysis software. Folic acid supplement intake showed no significant effect on colorectal cancer risk in meta-analysis of randomized controlled trials, RR: 1.07(95% CI: 0.86-1.43). The effect on risk was not significant in cohort studies either; RR=0.96(95% CI: 0.76-1.21). However, there was significant reduced colorectal cancer risk in total folate intake in cohort studies; 0.71 (95% CI: 0.59-0.86). Odds Ratio was also significantly reduced in case control studies; 0.77 (95% CI: 0.62-0.95). Nevertheless once folate status was measured as Red Blood Cell folate content, no significant effect on colorectal cancer risk was observed; 1.05 (95% CI: 0.85-1.30). The differences in bioavailability and metabolism of synthetic folic acid and natural dietary folate as well as variation in the baseline characteristics of subjects and various methods of folate status assessment might be the main reasons for these controversies. Findings of present study highlightthe importance of individualized folic acid supplement intake given the fact that the beneficiary effects of long term folic acid supplementation is not confirmed.

Assessment of Folate Status in Obese Patients: Should We Measure Folate in Serum or in Red Blood Cells?

Recent studies revealed that obesity is associated with decreased serum but at the same time increased red blood cell (RBC) folate concentrations compared with lean subjects, thus casting doubt upon the agreement between serum and RBC folate measurements for assessing folate status. This work aimed to determine whether these two metrics lead to the same classification of folate status in obese patients. RBC and serum folate concentrations were measured with a chemiluminescent immunoassay in 263 adults with body mass index ≥30kg/m2 and without previous bariatric surgery. Among them, 68.1% were eligible for bariatric surgery. Each serum and RBC folate result was classified as deficient or not according to thresholds recommended by the kit manufacturer (model A) or by the World Health Organization (model B). The agreement between serum and RBC folate results was evaluated using the proportion of overall agreement and the prevalence-adjusted bias-adjusted kappa (PABAK) statistics. The overall percentage agreements between serum and RBC measurements were 91.6% (95% CI 87.6-94.7%) and 92.4% (95% CI 88.5-95.3%) with PABAK coefficients of 0.87 (95% CI 0.82-0.93) and 0.88 (95% CI 0.83-0.94) in the models A and B, respectively, corresponding to almost perfect agreement. The same was true in the subgroup of patients eligible for bariatric surgery. Gender, age, and BMI did not influence the quality of agreement between the two parameters. The present study showed that folate measurements in serum and in RBC display similar performances to assess folate status in obese patients.

Quantitation of 5-Methyltetrahydrofolic Acid in Dried Blood Spots and Dried Plasma Spots by Stable Isotope Dilution Assays.

Because of minimal data available on folate analysis in dried matrix spots (DMSs), we combined the advantages of stable isotope dilution assays followed by LC-MS/MS analysis with DMS sampling to develop a reliable method for the quantitation of plasma 5-methyltetrahydrofolic acid in dried blood spots (DBSs) and dried plasma spots (DPSs) as well as for the quantitation of whole blood 5-methyltetrahydrofolic acid in DBSs. We focused on two diagnostically conclusive parameters exhibited by the plasma and whole blood 5-methyltetrahydrofolic acid levels that reflect both temporary and long-term folate status. The method is performed using the [2H4]-labeled isotopologue of the vitamin as the internal standard, and three steps are required for the extraction procedure. Elution of the punched out matrix spots was performed using stabilization buffer including Triton X-100 in a standardized ultrasonication treatment followed by enzymatic digestion (whole blood only) and solid-phase extraction with SAX cartridges. This method is sensitive enough to quantify 27 nmol/L whole blood 5-methyltetrahydrofolic acid in DBSs and 6.3 and 4.4 nmol/L plasma 5-methyltetrahydrofolic acid in DBSs and DPSs, respectively. The unprecedented accurate quantification of plasma 5-methyltetrahydrofolic acid in DBSs was achieved by thermal treatment prior to ultrasonication, inhibiting plasma conjugase activity. Mass screenings are more feasible and easier to facilitate for this method in terms of sample collection and storage compared with conventional clinical sampling for the assessment of folate status.

Haematological implications of folate food fortification

Reports from some Western countries indicate that mandatory folate food fortification (FFF) has substantially reduced the prevalence of folate deficiency, leading to calls for folate testing following FFF to be limited to specific indications such as macrocytic anaemia. This is premature for low-income countries, where folate deficiency is predominantly the result of poor intake coupled with the increasing demand in pregnancy. There is also evidence that HIV infection is prejudicial to folate nutrition, and low-income HIV-infected women and their offspring could be among the most susceptible to folate deficiency. In assessing folate nutrition, the value of serum folate has been compromised by FFF, and both serum and red cell folate are necessary for optimal assessment of folate status. Although the limited data available suggest that large-scale masking of vitamin B12 deficiency by FFF has not occurred, it has been suggested that B12 be incorporated into folate-fortified foods. However, significant B12 deficiency is usually due to malabsorption, and physiological doses added to food would be of questionable value because they would not be absorbed. Extensive work, especially randomised clinical trials, must be done before dietary intervention with B12 on a national scale can be justified.

Red cell or serum folate: what to do in clinical practice?

Folate deficiency has been linked to diverse clinical manifestations and despite the importance of accurate assessment of folate status, the best test for routine use is uncertain. Both serum and red cell folate assays are widely available in clinical laboratories; however, red cell folate is the more time-consuming and costly test. This review sought to evaluate whether the red cell assay demonstrated superior performance characteristics to justify these disadvantages. Red cell folate, but not serum folate, measurements demonstrated analytical variation due to sample pre-treatment parameters, oxygen saturation of haemoglobin and haematocrit. Neither marker was clearly superior in characterising deficiency but serum folate more frequently showed the higher correlation with homocysteine, a sensitive marker of deficiency. Similarly, both serum and red cell folate were shown to increase in response to folic acid supplementation. However, serum folate generally gave the greater response and was able to distinguish different supplementation doses. The C677T polymorphism of methylenetetrahydrofolate reductase alters the distribution of folate forms in red cells and may thereby cause further analytical variability in routine red cell folate assays. Overall, serum folate is cheaper and faster to perform than red cell folate, is influenced by fewer analytical variables and provides an assessment of folate status that may be superior to red cell folate.

Quantitation of Whole-Blood Total Folate within Defined MTHFR C677T Genotype Groups by Isotope Dilution–Liquid Chromatography–Tandem Mass Spectrometry Differs from Microbiologic Assay1–3

Standardization of folate measurement is needed for accurate assessment of folate status. We compared the measurement of whole-blood folate by isotope dilution–liquid chromatography–tandem MS (ID-LC-MS/MS) with the historical gold standard microbiological assay (MA) using 3 common calibrators within the frame of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. Seventy-three whole-blood samples with an even distribution of MTHFR C677T genotypes (24 CC, 24 CT, 24 TT) were prepared, and total folate was determined by ID-LC-MS/MS and MA using the following calibrators: 5-methyltetrahydrofolate (5-methylTHF) (Merck), folic acid (FA) (Merck), and FA (Sigma). To compare the methods, 5-formyltetrahydrofolate (5-formylTHF) was excluded in the ID-LC-MS/MS summation of total folate, because it is likely that the majority of 5-formylTHF detected is a pyrazino-s-triazine oxidation product of 5-methylTHF. MA whole-blood folate measured by using the FA calibrators was consistently higher than with the 5-methylTHF calibrator. Differences between dilutions and analysis of spiked whole-blood samples showed a nonlinear response, with overrecovery of 5-methylTHF by ~23% toward the higher end of the MA calibration range. Significant proportional biases between ID-LC-MS/MS and MA were found in all comparisons except when the MA was calibrated with 5-methylTHF and a higher sample dilution of 1:1600 (regression slope: 1.05; P= 0.31; intercept-21, P = 0.16). Calibration bias and matrix effects in the MA underscore the need for a formally accepted whole-blood folate reference method. ID-LC-MS/MS procedures have the potential to offer a high degree of accuracy; however, further work is needed to determine the origin of the pyrazino-s-triazine derivative.

Folate status assessment history: implications for measurement of biomarkers in NHANES

This article presents a historical perspective on the different methods used to measure folate status in populations and clinical settings. I discuss some of the advantages and limitations of these procedures. For >50 y researchers have used microbiological assay methods to assess folate status in clinical settings and in population-based studies, such as NHANES. Serum and red blood cell folate values obtained with the Lactobacillus casei assay have formed the basis for current ranges and cutoffs for the establishment of folate sufficiency and for the current dietary reference intakes for folate. Over the past 30 y competitive folate protein binding assays, which are available in kit form, have supplanted microbiological assays in many clinical laboratories because of their ease of use. Several NHANES cycles have used these assays. Folate concentrations obtained with these kits are lower than those from microbiological assays and show a wide variation between different protein binding assay kits. This variation has complicated the setting of values for normal ranges of folate status and the comparison of status changes between different NHANES cycles. The recent development of mass spectrometry methods for folate opens up the possibility of measurement of individual folate vitamers such as folic acid. Past experience with microbiological and competitive protein binding assays indicates some of the technical problems that research will need to address before this promise becomes reality.

Update on Folate and Human Health

Folate is an essential B vitamin found naturally in a variety of foods such as leafy vegetables, citrus fruits, liver, and lentils. There are many forms of folate, and folic acid is the form used in folate supplements and food fortification. Folate is involved in many reactions requiring the transfer of 1-carbon units, being essential for both DNA and RNA synthesis. Although folate was first demonstrated to be important for human health more than 70 years ago, only recently have health professionals begun to understand the full range of its physiological functions. For example, several controlled clinical trials have shown that increased consumption of folic acid may decrease the risk of neural tube defects. Other observational studies suggest inverse relationships between folate and risk for a variety of chronic diseases such as cancer and cardiovascular disease; controlled clinical trials to confirm these associations, however, are either in process or have tended not to support a simple cause-and-effect relationship. Assessment of folate status can involve both biochemical and dietary data, and it is important that clinicians understand the appropriate uses and limitations of these assessment tools. Because of the potential public health benefit of higher folate intakes on decreasing risk of neural tube defects, the Food and Drug Administration launched a national folic acid food fortification program that became fully effective in 1998. Dietary and biochemical analysis suggests that folate status has increased since the initiation of this program, although there is concern that folate intake now may be too high in some individuals. Still others argue that folate intake remains too low to achieve the original intended effect. Clearly, continued monitoring of this program is warranted. Although much has been learned about folate during the past 80 years, there is still much to ascertain about the mechanisms by which it exerts its numerous effects on human health

Liquid Chromatography–Tandem Mass Spectrometry Analysis of Folate and Folate Catabolites in Human Serum

Folate status is associated with several chronic diseases; thus accurate assessment of folate status has become important in the clinical setting and in epidemiological studies. The diversity of folate forms complicates the task of assaying endogenous folate. We developed and validated an assay that measures various forms of folate in addition to folate catabolites in human serum. We added ascorbic acid to serum samples from 168 healthy blood donors and 39 patients with renal failure, and precipitated the proteins with acetonitrile containing (13)C-labeled folate forms as internal standards. The supernatant was evaporated and the analytes redissolved in water. We then used liquid chromatography-tandem mass spectrometry to quantify 5-methyltetrahydrofolate (5mTHF), 4-alpha-hydroxy-5-methyltetrahydrofolate (hmTHF), folic acid (FA), 5-formyltrahydrofolate (5fTHF), p-aminobenzoylglutamate (pABG), and p-acetamidobenzoylglutamate (apABG). Detection limits were 0.07-0.52 nmol/L, and the assay was linear to 140 nmol/L for all analytes. The mean serum folate concentration from 168 blood donors was 22.7 nmol/L, of which 85.8% was 5mTHF, 12.1% hmTHF, 2.1% FA, and 0.0% 5fTHF. In the same individuals, the mean concentrations of pABG and apABG were 0.07 nmol/L and 0.47 nmol/L, respectively. The concentrations of folate catabolites were 22-30 times higher in 39 patients with renal failure. This folate assay correlated well with the microbiologic assay (r(2) = 0.92) and with measurement of serum folate as pABG equivalents (r(2) = 0.93). This method based on liquid chromatography-tandem mass spectrometry measures the most abundant folate species and 2 folate catabolites in human serum.

The importance of using folate intake expressed as dietary folate equivalents in predicting folate status

In order to achieve valid assessments of folate status, folate food composition data needs to be expressed in the same chemical form and units as the recommendations for folate intakes. Dietary folate (e.g. both naturally occurring and synthetic folic acid) and supplemental folic acid intakes were assessed twice in a cross-sectional study, using a validated dietary assessment method, the Food Choice Map, and two databases: the Canadian Nutrient File (CNF 2001), where folate was expressed as μg, and an updated version of the CNF 2001, where folate was expressed as dietary folate equivalents (DFEs). A fasting blood sample was used to measure serum folate. Statistically significant mean differences ( p < 0.05) were observed in the energy adjusted mean daily folate intakes from the original CNF (471 ± 216 μg/d; mean ± S.D.) versus those obtained from the updated database (648 ± 358 μg DFE/d; mean ± S.D.). No significant correlation was observed between the folate intakes assessed by the two versions of the database ( r = 0.1). Folate intakes estimated from either database were significantly correlated irrespective of folate supplement usage. Using the Estimated Average Requirement (EAR) as the nutritional cut-off point and serum folate as a biological cut-off point, folate intakes estimated as μg DFEs/d predict folate status better than the μg/d estimation. Assessment of folate nutritional status is incomplete if content values in the food composition database do not account for (1) the differences in bioavailability between naturally occurring folate and synthetic folic acid found as a food fortificant, and (2) folate supplement usage.

Review of the Magnitude of Folate and Vitamin B12 Deficiencies Worldwide

Human deficiencies of folate and vitamin B12 result in adverse effects which may be of public health significance, but the magnitude of these deficiencies is unknown. Therefore, we examine the prevalence data currently available, assess global coverage of surveys, determine the frequency with which vitamin status assessment methods are used, and identify patterns of status related to geographical distribution and human development. Surveys were identified through PubMed and the Vitamin and Mineral Nutrition Information System at the World Health Organization (WHO). Since different thresholds were frequently used to define deficiency, measures of central tendency were used to compare blood vitamin concentrations among countries. The percentage of countries with at least one survey is highest in the WHO Regions of South-East Asia and Europe. Folate and vitamin B12 status were most frequently assessed in women of reproductive age (34 countries), and in all adults (27 countries), respectively. Folate status assessment surveys assessed plasma or serum concentrations (55%), erythrocyte folate concentrations (21%), or both (23%). Homocysteine was assessed in one-third of the surveys of folate and vitamin B12 status (31% and 34% respectively), while methylmalonic acid was assessed in fewer surveys of vitamin B12 status (13%). No relationship between vitamin concentrations and geographical distribution, level of development, or population groups could be identified, but nationally representative data were few. More representative data and more consistent use of thresholds to define deficiency are needed in order to assess whether folate and vitamin B12 deficiencies are a public health problem.

Assessment of the potential effect of incremental increases in folic acid intake on neural tube defects in Australia and New Zealand

Objective: To estimate the number of neural tube defects that could be prevented in Australia and New Zealand by increasing levels of folic acid intake.Methods: Available data on prevalence of neural tube defects in Australia and New Zealand, folic acid supplement use and serum folate were used in a published model to estimate the number of neural tube defects that could be prevented in Australia and New Zealand for increments of folic acid intake from 0.1 mg daily to 1 mg daily.Results: An increase of 0.2 mg folic acid per day was estimated to result in the prevention of 49 (95% CI 27–84) neural tube defects per year in Australia and 11 (95% CI 6–18) in New Zealand. A separate estimation for Indigenous Australians found that 0.2mg of folic acid daily could prevent 7 (95% CI 4–11) neural tube defects in Indigenous infants per year.Conclusions: These data should be useful in considering primary preventive strategies for neural tube defects, including the possible introduction of mandatory fortifcation of food with folic acid. The estimates are imprecise because of limitations in the data used in the model.Implications: More representative and precise data on neural tube defects, serum folate levels and use of folic acid supplements from all Australian States and New Zealand are needed to refne the output from the model and to provide a baseline assessment of folate status against which to measure the effects of any future interventions to prevent neural tube defects.

Plasma folate as marker of folate status in epidemiological studies: the European Investigation into Cancer and Nutrition (EPIC)-Potsdam study.

Folate deficiency is often discussed as a potential risk factor for CVD and some cancers. Reliable assessment of folate status in large-scale epidemiological studies is therefore of major importance. The present study assessed the value of plasma folate (PF) compared with erythrocyte folate (EF) as a marker of folate status in 363 participants in the European Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort. EF and PF, total homocysteine (tHcy), pyridoxine, cobalamin, creatinine, total protein and packed cell volume were determined; glutamate carboxypeptidase (GCP) C1561T, reduced folate carrier (RFC) G80A and methylenetetrahydrofolate (MTHFR) C677T polymorphisms were analysed. Anthropometric measurements were taken and dietary intake was assessed with the EPIC-Potsdam food-frequency questionnaire. Comparison of EF and PF with factors that may modulate their concentrations was performed. Cross-classification of blood folates in quintile categories resulted in correct classification into the same or adjacent category of 75.5 % of all subjects. Age, BMI, pyridoxine and cobalamin, fruit and vegetable intake, and vitamin supplementation 24 h before blood draw were positively associated with EF and with PF. For tHcy an inverse association was found. Participants with the MTHFR 677TT genotype showed significantly elevated EF concentrations compared with those with 677CT genotype; EF and PF were more strongly correlated (r 0.78, P<0.0001) for participants with MTHFR 677TT genotype than for those with the 677CC or 677CT genotype. In summary, our present results indicate that plasma folate seems to be a suitable marker for assessment of folate status for use in large-scale epidemiological studies.

Assessment of Folate Status: Measurement of Homocysteine versus Vitamin B12 and Folate

Abstract This study was based on 63 subjects (mean age 50 ± 9) including 41 patients with clinical and objective investigational evidence of vascular disease (age 30-66 years) and 22 control subjects (age 26-54 years). Dietary intake of folate was estimated from a food questionnaire of folate (Q.folate). There was no statistically significant difference between controls and patients for dietary folate. Also the plasma folate level did did noly slightly differ between the controls and patients (6.68 ± 2.52 ng/mL versus 5.62 +4.16 ng/mL, not significant). Patients had higher average homocysteine concentrations than control subjects (12.93 ± 8.79 vs 9.07 ± 3.08 μmol/l, p&lt;0.05). A significant relationship was observed in controls between plasma folate concentrations and the homocysteine levels (rs = - 0.538; p&lt;0.01), and the folate questionnaire (rs = 0.697; p&lt;0.001). We found in controls significant positive correlation between vitamin B12 and vitamin B6 (rs = 0.475, p&lt;0.05). By contrast, no association v/as found in patients between folate and homocysteine concentrations and the dietary nutrient intake of folate. On the other hand vitamin B12 is inversely associated with homocysteine (rs = -0.333, p&lt;0.05). These data provide further evidence that plasma homocysteine is an independent risk factor for myocardial infraction. Homocysteine is a valuable functional index of micronutrient status and intakes for people, which can assist the development of the public health. In our population, folate was the most important determinant of plasma homocysteine, even in subjects with apparently adequate nutritional status of this vitamin.