Epidemiological survey of vitamin deficiencies in older Thai adults: implications for national policy planning

Vitamin E and cardiovascular diseases: an interest to public health?

Cardiovascular diseases (CVD) are the leading cause of death worldwide. From this perspective, the role of vitamin E and its metabolites in preventing CVD has been studied, being supported by the findings that low vitamin E concentrations are associated with an increased risk of cardiovascular events. Despite this, no studies have analysed the co-existence of vitamin E deficiency (VED) and CVD on the basis of population studies. Facing that, this study summarises information on the relationship between vitamin E status and CVD, providing a basis for understanding the determining and protective factors for its development. VED may be a public health problem since it has been observed to vary from 0·6% to 55·5% worldwide, with higher percentages in Asia and Europe, where CVD mortality rates stand out. Intervention studies with α-tocopherol supplementation do not confirm cardioprotective action of vitamin E, which may reflect that α-tocopherol alone does not provide cardiovascular protection to individuals, but the consumption of all isomers found in food. Considering that low concentrations of α-tocopherol can lead to a higher susceptibility to diseases involving oxidative stress in the population, in addition to the high and growing prevalence of CVD and VED, it is essential to investigate or reinterpret the mechanisms of action of vitamin E and its metabolites in the cardiovascular process to better understand the co-existence of CVD and VED. It is also important to implement public health policies and programmes aimed at promoting the consumption of natural food sources of vitamin E and healthy fats.

Interleukin-8 and neutrophil extracellular traps in children with lupus nephritis and vitamin C deficiency

BACKGROUND

Vitamin C is a potent scavenger of reactive oxygen species, which induce neutrophil extracellular trap (NET) formation. NETs are a major source of autoantigens and are involved in systemic lupus erythematosus (SLE) pathogenesis. We determined vitamin C status and evaluated NET formation and inflammatory cytokines in children with lupus nephritis.

METHODS

Serum vitamin C was measured in 46 patients (82.6% females, mean age 14.5 ± 0.3 years). Vitamin C levels < 0.3 mg/dL indicated vitamin C deficiency. Patients were divided into two groups according to serum vitamin C levels: normal and low (< 0.3 mg/dL). We compared NET formation and levels of SLE-related cytokines, including interleukin (IL)-8, IL-10, and tumor necrosis factor-α (TNF-α), between groups. NET formation was determined through measurement of serum citrullinated histone 3 levels and mRNA expression of peptidyl arginine deiminase-4 and assessment of the percentage of neutrophils with NETs by immunofluorescence.

RESULTS

Nine patients (19.6%) had vitamin C deficiency. Kidney pathology assessment at disease onset revealed that histological activity index and number of kidney biopsies containing crescentic glomeruli were higher in vitamin C-deficient patients, but chronicity index was not. NET formation and serum IL-8 were more prominent in vitamin C-deficient patients. Serum IL-8 levels were 12.9 ± 5.2 pg/mL in low vitamin C group and 5.2 ± 0.9 pg/mL in normal vitamin C group (p = 0.03). Serum IL-10 and TNF-α were similar between groups.

CONCLUSIONS

Our study demonstrated correlation among vitamin C deficiency, increased NET formation, and IL-8 upregulation in children with lupus nephritis. A prospective study is required to evaluate cause‒effect relationships of vitamin C status, NET formation and IL-8 expression.

Nutritional peripheral neuropathies

Nutritional peripheral neuropathies are a global problem, heavily influenced by geopolitical, cultural and socioeconomic factors. Peripheral neuropathy occurs most frequently secondary to B-vitamin deficiencies, which is suspected to increase in years to come due to the popularity of vegan and vegetarian diets and increased use of bariatric surgery.This review will focus on the common B-vitamins for which a causal link to peripheral neuropathy is more established (vitamins B1, B2, B6, B9 and B12). We will review the historical human and animal data on which much of the clinical descriptions of vitamin deficiencies are based and summarise current available tools for accurately diagnosing a nutritional deficiency. We will also review recently described genetic diseases due to pathogenic variants in genes involved in B-vitamin metabolism that have helped to inform the phenotypes and potential causality of certain B-vitamins in peripheral neuropathy (B2 and B9).Endemic outbreaks of peripheral neuropathy over the last two centuries have been linked to food shortages and nutritional deficiency. These include outbreaks in Jamaican sugar plantation workers in the nineteenth century (Strachan's syndrome), World War two prisoners of war, Cuban endemic neuropathy and also Tanzanian endemic optic neuropathy, which remains a significant public health burden today. An improved understanding of lack of which vitamins cause peripheral neuropathy and how to identify specific deficiencies may lead to prevention of significant and irreversible disability in vulnerable populations.

The Association Between Vitamin B1 Deficiency and Anemia Among Elderly Patients at a Rural Hospital in Japan: A Cross-Sectional Study

Background and objective Vitamin B1 deficiency can cause a variety of abnormalities in the neuropsychiatric, cardiovascular, and other systems. This condition can be rapidly corrected and prevented from progressing to irreversible sequelae through vitamin B1 supplementation. Therefore, early detection of and intervention in vitamin B1 deficiency are essential. We have previously demonstrated an association between vitamin B1 deficiency and appetite loss in hospitalized older adult patients in rural Japan. This study aimed to examine the additional predictors of vitamin B1 deficiency in patients with appetite loss and other symptoms suggestive of vitamin B1 deficiency. Material and methods This cross-sectional study involved 519 patients admitted to a rural hospital between April 2020 and March 2022. Data on vitamin B1 levels, age, sex, BMI, albumin levels, functional independence measure (FIM), hemoglobin levels, Charlson Comorbidity Index (CCI), and medications were collected from electronic medical records. Vitamin B1 deficiency was defined as serum vitamin B1 level <20 µg/dL. Data were analyzed using the Mann-Whitney U test, Student's t-test, and chi-square test, followed by multivariate logistic regression to examine the predictors of vitamin B1 deficiency. Results A total of 113 patients (21.5%) were found to be vitamin B1-deficient. Multivariate logistic regression showed that anemia was significantly associated with vitamin B1 deficiency [adjusted odds ratio (AOR): 1.71, 95% confidence interval (CI): 1.07-2.73, p<0.05]. Conclusion Based on our findings, anemia is significantly associated with vitamin B1 deficiency in hospitalized Japanese patients living in rural areas. Therefore, physicians should be mindful of the possibility of vitamin B1 deficiency in hospitalized patients with anemia.

The low prevalence rate of vitamin E deficiency in urban adults of Wuhan from central China: findings from a single-center, cross-sectional study

Background

Vitamin E is an essential nutrient in human body famous for its antioxidant and non-antioxidant functions. However, little is known about vitamin E deficiency status in urban adults of Wuhan from central China. Our aim is to describe the distribution of both circulating and lipid-adjusted serum vitamin E concentration in urban adults of Wuhan.

Methods

We hypothesized that the prevalence rate of vitamin E deficiency would be low in Wuhan in consideration of the Chinese food composition. A cross-sectional study with 846 adults was performed in a single-center. Concentrations of vitamin E were measured by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS).

Results

The median (interquartile range, IQR) of serum vitamin E concentration was 27.40 (22.89–33.20) μmol/L while that of serum vitamin E concentration adjusted by total cholesterol or the sum of cholesterol (TC) and triglyceride (TG) (the sum of cholesterol and triglyceride, TLs) were 6.20 (5.30–7.48) and 4.86 (4.10–5.65) mmol/mol, respectively. No significant difference of the circulating and TC-adjusted vitamin E concentration was found between male and female except for vitamin E/TLs. However, concentrations of vitamin E increased significantly (r = 0.137, P < 0.001) with age, but lipid-adjusted concentrations of vitamin E did not. On analysis of risk factors, the subjects characterized by hypercholesterolemia are more likely to exhibit higher circulating but lower lipid-adjusted vitamin E level due to adequacy of the serum carriers for delivery of vitamin E. Only 0.47% of the population were below 12 μmol/L of vitamin E defined as functional deficiency.

Conclusion

The prevalence rate of vitamin E deficiency in urban adults of Wuhan is low, which is important and useful to clinicians for clinical decision-making in public health practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-023-01103-9.

Usual intake of one-carbon metabolism nutrients in a young adult population aged 19-30 years: a cross-sectional study

One-carbon nutrients play an important role in epigenetic mechanisms and cellular methylation reactions. Inadequate intake of these nutrients is linked to metabolic perturbations, yet the current intake levels of these nutrients have rarely been studied in Asia. This cross-sectional study surveyed the usual dietary intake of one-carbon nutrients (folate, choline and vitamins B2, B6 and B12) among Thai university students aged 19-30 years (n 246). Socioeconomic background, health information, anthropometric data and 24-h dietary recall data were collected. The long-term usual intake was estimated using the multiple-source method. The average usual intake levels for men and women were (mean ± sd) 1⋅85 ± 0⋅95 and 2⋅42 ± 8⋅7 mg/d of vitamin B2, 1⋅96 ± 1⋅0 and 2⋅49 ± 8⋅7 mg/d of vitamin B6, 6⋅20 ± 9⋅5 and 6⋅28 ± 12 μg/d of vitamin B12, 195 ± 154 and 155 ± 101 μg dietary folate equivalent/d of folate, 418 ± 191 and 337 ± 164 mg/d of choline, respectively. Effect modification by sex was observed for vitamin B2 (P-interaction = 0⋅002) and choline (P-interaction = 0⋅02), where every 1 mg increase in vitamin B2 and 100 mg increase in choline intake were associated with a 2⋅07 (P = 0⋅01) and 0⋅81 kg/m² (P = 0⋅04) lower BMI, respectively, in men. The study results suggest that Thai young adults meet the recommended levels for vitamins B2, B6 and B12. The majority of participants had inadequate folate intake and did not achieve recommended intake levels for choline. The study was approved by the Ethics Committee at the Faculty of Medicine, Chiang Mai University. This trial was registered at www.thaiclinicaltrials.gov (TCTR20210420007).

Association between transient appetite loss and vitamin B1 deficiency in elderly patients with suspected deficiency

BACKGROUND

There is scarce evidence associating vitamin B1 levels and appetite loss duration in elderly patients with suspected B1 deficiency. We aimed to investigate this association in elderly hospitalized patients with suspected vitamin B1 deficiency in rural Japan.

METHODS

This cross-sectional study evaluated 309 elderly patients (aged ≥ 65 years) admitted to one rural Hospital between April 2017 and March 2019. We collected data on vitamin B1 level, age, sex, body mass index, albumin levels, area of residence, long-term care, dependent conditions, activities of daily living, Charlson comorbidity index, and appetite loss from the patients' electronic medical records. Vitamin B1 deficiency was defined as serum vitamin B1 levels <20 μg/dL. Data were analyzed using the Mann-Whitney U, Student's t, and chi-square tests, followed by multivariable logistic regression, to examine the association between vitamin B1 deficiency and appetite loss.

RESULTS

Eighty-eight (28.5%) patients had vitamin B1 deficiency. In multivariable logistic regression, appetite loss (for both < 1 and > 1 week) before admission to the hospital showed a significant association with vitamin B1 deficiency (adjusted odds ratio [AOR] =10.80, 95% confidence interval [CI]: 5.16-22.00, P < .001; and AOR = 5.77, 95% CI: 2.88-11.50, P < .001, respectively).

CONCLUSIONS

Appetite loss is associated with vitamin B1 deficiency in elderly Japanese patients living in rural areas. Therefore, physicians should be aware of the possibility of vitamin B1 deficiency in elderly patients with appetite loss and focus on early intervention.

Vitamin E status in healthy population in Asia: A review of current literature

Vitamin E is a lipid soluble antioxidant which mainly circulates as α-tocopherol in the human plasma. Its deficiency is associated with ataxia, neuropathy, anaemia and several other health conditions. Although substantial data on vitamin E status has been published worldwide, there is paucity of data on the extent of deficiency from most Asian countries, including India. Part of the problem is lack of validated biomarkers for vitamin E and no consensus on cut offs for defining deficiency and sufficiency. Thus, interpretation of the data on the vitamin E status is difficult. Limited available data from 31 studies on vitamin E status in healthy people from Asia, the most populated continent, has been collated for the purpose of this review. Broadly, the results suggest inadequate vitamin E status in most age groups, with the prevalence of deficiency reaching 67%, 80%, 56% and 72% in infants, children and adolescents, adults, elderly and pregnant women, respectively, based on varying cut offs. The findings are not surprising as both, vitamin E intakes and its status have not received too much attention in the past. Lack of conclusive data accentuates the need for more research on the vitamin E status across all age groups and to define age, gender and physiological state specific cut offs for vitamin E levels.

Association of physical activity, vitamin E levels, and total antioxidant capacity with academic performance and executive functions of adolescents

BACKGROUND

Although various studies have shown the effect of vigorous physical activity on academic achievements, no studies have investigated the effect of vitamin E levels on academic performance. The present study aimed to assess the association between physical activity, vitamin E levels and total antioxidant capacity on the academic performance and executive functions of adolescents aged 15-18 years.

METHODS

The physical activity of participants was assessed according to the time spent engaging in moderate and intense exercise programs. Participants were classified into three groups representing mild, moderate, and high activity. Serum total antioxidant capacity was measured using a colorimetric assay kit. Vitamin E was estimated by the α- and γ-tocopherol levels in fasting serum samples using high-performance liquid chromatography paired with a diode array detector. School grades (ranging from 1.0, very poor; to 10.0, outstanding) were obtained at the end of the academic year to evaluate academic performance and executive functions.

RESULTS

A total of 120 school students (mean age 16.36 ± 0.77 years; 70 boys, 50 girls) participated in the study. Academic performance was higher for students classified as moderately or highly active compared with those in the mild activity group. Serum levels of vitamin E, total antioxidant capacity, and leisure-time physical activity were also higher in the moderate and high activity groups. There was a significant correlation between age, gender, body mind index, α- and γ-tocopherol, total antioxidant capacity, leisure-time physical activity and academic performance.

CONCLUSIONS

The academic performance and executive function scores were found to be positively correlated with age, gender, α- and γ-tocopherol, total antioxidant capacity, and physical activity; and were negatively correlated with body mind index. Our findings indicate that physical activity should be promoted during and after school hours, along with a healthy balanced diet including vitamin E.

Associations among serum folate, waist-to-hip ratio, lipid profile, and eating habits with homocysteine in an elderly Thai population

A lower serum folate level is common in older populations and is associated with increased serum homocysteine concentration. In turn, an elevated homocysteine level is associated with increased risk of cardiovascular disease and age-related diseases. Contemporary studies of folate and dietary risk factors for cardiovascular disease among the elderly population in Thailand are lacking. This cross-sectional study aimed to investigate the relationships among serum folate, homocysteine level, and nutritional status in the elderly Thai. Three hundred individuals, aged 60 years and over, underwent anthropometric and physiological measurements, and biochemical parameters, and eating habits were also determined. Folate insufficiency was found in approximately 35% of subjects. Folate and homocysteine showed a significant inverse correlation. Serum homocysteine levels rose with increasing age. Folate deficiency and high waist-to-hip ratio were associated with 7-fold and 2.5-fold increased risk for hyperhomocysteinemia, respectively. There were positive correlations between homocysteine and waist-to-hip ratio and systolic blood pressure, but a negative correlation between homocysteine and high-density lipoprotein (r = -0.239, p < 0.01), which are markers for cardiovascular disease risk. Folate negatively correlated with body mass index, waist-to-hip ratio, and diastolic blood pressure, but positively with high-density lipoprotein (r = 0.162, p < 0.01). Investigation of eating habits showed that low consumption of green leafy vegetables and high consumption of sugary foods were associated with high homocysteine levels. Given associations between nutritional status and cardiovascular disease confirmed in this study, nutrition education, holistic health promotion, and appropriate behavioral modification of eating habits represent important measures for preventing premature cardiovascular disease in the elderly Thai population.

Thiamin deficiency in low- and middle-income countries: Disorders, prevalences, previous interventions and current recommendations

BACKGROUND

Thiamin deficiency is a major public health concern in several low- and middle-income countries (LMICs)-current attention to the problem is lacking.

AIM

This review discusses prevalence of thiamin insufficiency and thiamin-deficiency disorders (TDDs) in LMICs, outlines programmatic experience with thiamin interventions, and offers recommendations to improve public-health and research attention to thiamin in LMICs.

DISCUSSION

Thiamin insufficiency, i.e. low-blood-thiamin status, is endemic among several Southeast Asian countries: Cambodia (70-100% of infants and 27-100% of reproductive-age women); Laos (13% of hospitalized infants); Thailand (16-25% of children and 30% of elderly adults). Thiamin deficiency accounts for up to 45% of under-5 deaths in Cambodia, 34% of infant deaths in Laos, and 17% of infant deaths in Myanmar. Deficiency also exists in Africa, Asia, and the Americas, but these instances have typically been isolated. Exclusively breastfed infants of thiamin-deficient mothers are at highest risk for TDD and related death. Intervention strategies that have been employed to combat thiamin deficiency include food processing, fortification, supplementation, dietary diversification, and dietary behaviors, all of which have shown varying levels of effectiveness.

CONCLUSIONS

We recommend universal thiamin-fortification of context-specific staple-foods in LMICs as a promising solution, as well as thiamin supplementation, particularly for pregnant and lactating women. Food processing regulations, dietary diversification, and modification of dietary behaviors to increase consumption of thiamin-rich foods may provide benefits in some circumstances, especially in countries without universal fortification programs or in populations dependent on food aid.

Vitamin E deficiency in South Asian population and the therapeutic use of alpha-tocopherol (Vitamin E) for correction of anemia

Mild to moderate vitamin E deficiency because of inadequate consumption of vitamin E-rich foods and intestinal fat malabsorption is common in growing children, women of reproductive age and elderly South Asian population. Severe vitamin E deficiency may lead to peripheral and motor neurodegenerative diseases (e.g ataxia and motor skeletal myopathy), impaired immune response and free radical-induced hemolytic anemias. Vitamin E insufficiency and/or deficiency status in the general Pakistani population has not been sufficiently investigated. Moreover, there are challenges in determining vitamin E status in apparently healthy humans due to variations in their age, sources of consumed vitamin E and plasma lipid levels. Oxidative stress-induced reactive oxygen species have been shown to cause ineffective erythropoiesis and enhanced lysis of erythrocytes in some of the experimental animals and humans. Several studies on patients with various types of inherited hemolytic anemias, chronic renal disease, premature low birth infants and apparently healthy humans have shown that vitamin E might be therapeutically effective in the prevention and/ or treatment of anemia in these subjects.

Lifestyle behaviors and serum vitamin C in the Thai population in Bangkok Metropolitan

This study aimed to investigate the influence of lifestyle behaviors on the vitamin C levels in the circulating blood of the Thai population in Bangkok Metropolitan. The participants (n=250) included community workers (i.e., construction and business office workers) from the Bangkok Metropolitan, and the participants were placed in various behavior and lifestyle groups (Group I: reference; Group II: alcohol drinkers; Group III: outdoor workers; Group IV: smokers; and Group V: combined). The results showed that the lowest and highest vitamin C intakes were 7 and 27 mg/day in Groups IV and III, respectively. Group I (indoor workers free of smoking and drinking), had the highest total serum vitamin C level (39.7 µmol/L), while Group V (outdoor workers with smoking and drinking), had the lowest value (12.5 µmol/L). Furthermore, Group V had the highest prevalence (44 %) of total serum vitamin C deficiency (<11 µmol/L), while Group I had the lowest deficient indication (8 %). The vitamin C dietary intake and total serum levels were positively correlated in the reference group (Spearman's correlation=0.402, p < 0.05) but not in the other four groups. The significant adjusted odds ratio of inadequate total serum vitamin C (< 23 µmol/L) was 2.90 (CI: 1.15, 7.31) in Group IV and 3.73 (CI: 1.42, 9.81) in Group V. Moreover, the tendency to have an inadequate total serum vitamin C level was demonstrated in the following order: Group I < II < III < IV < V. Our results indicated that outdoor workers (Group III) and smokers (Group IV) had a greater likelihood of having a vitamin C deficiency than the reference group. A high percentage of deficiency was clearly observed among the outdoor workers with smoking and drinking behaviors (Group V).

Lactic acid fermentation as a tool for increasing the folate content of foods

Folate is an essential micronutrient involved in numerous vital biological reactions. The dietary consumption of naturally occurring vitamin B9 is often inadequate in many countries, and supplementation or fortification programs (using synthetic folic acid) are implemented to alleviate folate deficiency. Other food-based alternatives are possible, such as the use of lactic acid bacteria (LAB) to synthesize folate during fermentation. Many studies have been conducted on this topic, and promising results were reported for some fermented dairy products. However, in other studies, folate consumption by LAB or rather low folate production were observed, resulting in fermented foods that may not significantly contribute to the recommended B9 intake. In addition, the optimum conditions for folate biosynthesis by LAB are still not clear. The aim of this review was thus to (i) clarify the ability of LAB to produce folate in food products, (ii) check if the production of folate by LAB in various fermented foods is sufficient to meet human vitamin B9 requirements and (iii) suggest ways to optimize folate production by LAB in fermented food products.

Anemia in the Elderly in Northeastern Thailand: A Community-Based Study Investigating Prevalence, Contributing Factors, and Hematologic Features

This community-based study investigated anemia prevalence and certain hematologic features and their possible relationships to thalassemia and iron deficiency (ID) in a population of older people in Northeastern Thailand. Participants included 319 apparently healthy individuals ranging in age from 60 to 98 years, whose current health status was assessed by means of personal interviews. Blood samples were also collected to determine the following parameters: red blood cell indices, serum ferritin, C-reactive protein, hemoglobin profiles, and the α0-thalassemia gene. Based upon established WHO criteria, the overall prevalence of anemia was found to be 47.7%, increasing from 39% within the age group of 60-70 years to 68% in those >80 years. Factors considered to be significant contributors to anemia were classified as ID (3.6%), thalassemia (56.2%), and "unknown" (40.1%). Overall, only 2.4% of participants exhibited any ID. Hematologic changes appear to correlate with age. Our findings provide not only baseline information, potentially useful for implementing appropriate control measures, but also an enhanced awareness and understanding of the factors contributing to anemia among the elderly in the region.

An evidence-based systematic review of vitamin A by the natural standard research collaboration

An evidence-based systematic review of vitamin A by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated and reproducible grading rationale. This paper includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Association of Thr420Lys polymorphism in DBP gene with fat-soluble vitamins and low radial bone mineral density in postmenopausal Thai women

AIMS

To investigate the genetic markers for osteoporosis bone mineral density by the genotyping of rs7041, rs4588 and rs1352845 in the DBP gene with either bone mineral density or serum 25-hydroxycholecalciferol, retinol and α-tocopherol, among 365 postmenopausal Thai women.

MATERIALS & METHODS

The DBP genotypes were analyzed by a PCR restriction fragment-length polymorphism method. Serum 25-hydroxycholecalciferol was assessed using a commercial chemiluminescent immunoassay. Serum retinol and α-tocopherol were measured by reverse-phase high-performance liquid chromatography.

RESULTS

After adjustment for age >50 years, elder Thai subjects with low BMI (≤25 kg/m(2)) and carrying the rs4588 CC genotype had a higher risk of radial bone mineral density osteoporosis (odds ratio: 6.29; p = 0.048). The rs1352845 genotype also had a statistical association with total hip bone mineral density; however, it disappeared after adjustment for age and BMI. No association was found in fat-soluble vitamins with bone mineral density.

CONCLUSION

DBP genotypes may influence the osteoporosis bone mineral density in postmenopausal Thai women.

Vitamin E deficiency in developing countries

In addition to its role as a potent antioxidant, vitamin E is involved in a wide range of physiological processes, ranging from immune function and control of inflammation to regulation of gene expression and cognitive performance. Results from multiple studies suggest that poor nutritional status and higher prevalence of other oxidative stressors such as malaria and HIV infection predispose populations in developing countries for vitamin E deficiency. Although direct comparison between study outcomes is complicated by varied definitions of vitamin E deficiency, data trends indicate that children and the elderly are more vulnerable age groups and that men may be at higher risk for deficiency than women. Public health initiatives aimed at improving the vitamin E status of high-risk populations in developing countries would be prudent to counteract oxidative stress, improve immune function, and protect against neurologic and cognitive deficits. Additional research is needed to establish dose-response relationships of various interventions and to develop cost-effective, culturally-appropriate, and targeted programs.

Biomarkers of cobalamin (vitamin B12) deficiency and its application

Cobalamin (vitamin B12) deficiency in the elderly is an under recognized problem in daily clinical practice. It seems to be important because the deficiency of this vitamin can lead to irreversible neurological damage, anemia, osteoporosis, and cerebrovascular and cardiovascular diseases. Some clinical abnormalities that we thought were related to the normal aging changes may actually be caused by cobalamin deficiency, such as lack of ankle jerk reflex. The prevalence of cobalamin deficiency increases with age (ranges from 0.6% to 46% depending on the population studies and criteria for diagnosis). Other than clinical manifestations, there are some biomarkers for detection of cobalamin deficiency: the red blood cell mean corpuscular volume (MCV); serum cobalamin level; plasma holotranscobalamin; serum methylmalonic acid (MMA) levels and serum homocysteine levels. The interpretation and the application of these biomarkers are here presented.

Thalassemia and iron deficiency in a group of northeast Thai school children: relationship to the occurrence of anemia

The cross-sectional study assessed anemia, thalassemia, and hemoglobinopathies, as well as iron deficiency, among 190 northeastern Thai school children aged 10 to 11 years. The aim was to analyze the reasons for anemia among the group. Hemoglobin concentration and other hematological parameters were determined using an automated blood cell counter. Beta-thalassemia and other hemoglobinopathies were identified by high performance liquid chromatography (HPLC) analysis of hemoglobin. Alpha-thalassemia was identified by polymerase chain reaction (PCR) and related techniques. Iron deficiency was assessed using serum ferritin (SF) <20 ng/ml as indicator. Based on the WHO criteria, anemia was defined by hemoglobin (Hb) level <11.5 g/dl. Twenty five out of 190 children (13.2%; 95% CI = 8.7-18.8%) were anemic. Iron deficiency was found in only two out of 190 children (1.0%; 95% CI = 0.1-3.8%), but the two iron deficient children were not anemic. The proportion of thalassemia and hemoglobinopathies among the group was 61.1% (95% CI = 53.7-68.0%). As underlying reasons for anemia, thalassemia and hemoglobinopathies were found in 22 out of 25 (88.0%) anemic children. Beta-thalassemia and homozygous Hb E seem to be important, while this was less obvious for heterozygous α-thalassemia and heterozygous Hb E.

CONCLUSION

The results suggest that thalassemia and hemoglobinopathies may be major contributing factors to the occurrence of anemia in this area among the children's population.

Aflatoxin-albumin adducts and correlation with decreased serum levels of vitamins A and E in an adult Ghanaian population

A study of aflatoxin (AF) exposure and the levels of vitamins A and E was carried out with a group of 507 Ghanaian participants. AFB(1)-albumin adducts (AFB-AA) were measured by radioimmunoassay and vitamins A and E were measured by high-performance liquid chromatography (HPLC). The average level of serum AFB-AA was 0.94 +/- 0.64 (range = 0.1-4.44) pmol mg(-1) albumin. Mean levels of vitamins A and E were 1.32 +/- 0.48 (range = 0.41-4.85) micromol l(-1) and 15.68 +/- 4.12 (range = 6.35-30.40) micromol l(-1), respectively. A significantly negative correlation was found between serum AFB-AA and vitamin A levels (r = -0.110, p = 0.013). An even stronger, significant negative, correlation was found between serum AFB-AA and vitamin E levels (r = -0.149, p < 0.001). Serum AFB-AA levels were statistically higher (median = 0.985 pmol mg(-1) albumin) in subjects who had low levels of both vitamins A and E as compared with the levels (median = 0.741 pmol mg(-1) albumin) subjects who had high vitamins A and E levels (p(trend) = 0.001). To verify these findings, blood samples were again collected from 165 of the 507 people 3 months after the initial collection. Significantly negative correlations were confirmed between levels of serum AFB-AA and both vitamins A (r = -0.232, p = 0.003) and E (r = -0.178, p = 0.023). Again, high serum AFB-AA concentrations (median = 1.578 pmol mg(-1) albumin) were found in subjects with low levels of vitamins A and E compared with the concentrations (median = 1.381 pmol mg(-1) albumin) in subjects with high levels of vitamins A and E (p(trend) = 0.002). These data show that AF exposure was associated with decreased levels of serum vitamins A and E in high-risk human populations, which may significantly influence the incidence of AF-related adverse health effects.

Serum concentration and dietary intake of vitamins A and E in low-income South African elderly

BACKGROUND & AIMS

Adequate dietary intake of antioxidants is vital for the promotion of health, well being and longevity of the elderly. This study assessed the prevalence of vitamin A (retinol) and vitamin E (alpha-tocopherol) deficiency in a population of low-income South African elderly.

METHODS

Serum vitamin A and vitamin E concentrations were determined in 235 persons aged 60-93 years in Sharpeville, South Africa. Dietary assessment was done using 24-h recall. Weight and height were measured to determine body mass index.

RESULTS

The mean and standard deviation of serum levels in the elderly were 1.41+/-1.4 micromol/L for vitamin A and 2.1+/-1.1 mg/l for vitamin E. The proportion with deficient serum vitamin A was 28.2% and 26.5% for men and women respectively and 20.5% and 20.9% respectively for deficient vitamin E concentrations. Almost one-third of the subjects consumed less than 100% of the Estimated Average Requirement for both vitamins. Mean vitamin A intake was 426+/-666 microg in men and 368+/-811 microg in women, mean vitamin E intake for men and women was 5.4+/-5.2 microg and 4.0+/-0.5 mg respectively. The predominant macronutrient consumed was carbohydrate. No relationship existed between biochemical and dietary intake parameters of vitamins A and E.

CONCLUSIONS

These findings indicate poor dietary intake and high prevalence of vitamins A and E deficiency among this elderly population. Sustainable community-based interventions are needed to address this nutritional vulnerability in this community.

The reduced folate carrier (RFC) is cytotoxic to cells under conditions of severe folate deprivation. RFC as a double edged sword in folate homeostasis

The reduced folate carrier (RFC), a bidirectional anion transporter, is the major uptake route of reduced folates essential for a spectrum of biochemical reactions and thus cellular proliferation. However, here we show that ectopic overexpression of the RFC, but not of folate receptor alpha, a high affinity unidirectional folate uptake route serving here as a negative control, resulted in an approximately 15-fold decline in cellular viability in medium lacking folates but not in folate-containing medium. Moreover to explore possible mechanisms of adaptation to folate deficiency in various cell lines that express the endogenous RFC, we first determined the gene expression status of the following genes: (a) RFC, (b) ATP-driven folate exporters (i.e. MRP1, MRP5, and breast cancer resistance protein), and (c) folylpoly-gamma-glutamate synthetase and gamma-glutamate hydrolase (GGH), enzymes catalyzing folate polyglutamylation and hydrolysis, respectively. Upon 3-7 days of folate deprivation, semiquantitative reverse transcription-PCR analysis revealed a specific approximately 2.5-fold decrease in RFC mRNA levels in both breast cancer and T-cell leukemia cell lines that was accompanied by a consistent fall in methotrexate influx, serving here as an RFC transport activity assay. Likewise a 2.4-fold decrease in GGH mRNA levels and approximately 19% decreased GGH activity was documented for folate-deprived breast cancer cells. These results along with those of a novel mathematical biomodeling devised here suggest that upon severe short term (i.e. up to 7 days) folate deprivation RFC transport activity becomes detrimental as RFC, but not ATP-driven folate exporters, efficiently extrudes folate monoglutamates out of cells. Hence down-regulation of RFC and GGH may serve as a novel adaptive response to severe folate deficiency.