Is there a physiological role of vitamin C in iron absorption?

Effect of process parameters on vitamins and sensory acceptability in micronutrient-fortified soymilk prepared by small-scale batch processing

Effects of holding time before cooling, cooling method, and light or dark refrigerated storage on the stability of vitamin A, vitamin C, thiamine, riboflavin, and folate were investigated in fortified and unfortified soymilk. Vitamin C loss (6%) and mild vitamin A isomerization occurred when soymilk was held hot after fortification. Cooling bottled soymilk at ambient temperature or in an ice-water bath did not affect any vitamins. Loss of riboflavin (18%) and vitamin A isomerization occurred during 12 days of light-exposed refrigerated storage, in contrast to no vitamin degradation during dark refrigerated storage. A sensory panel of youth and children indicated no significant preferences between fortified and unfortified soymilk except for color, where the lighter-colored unfortified soymilk was preferred. Acceptable vitamin stability and sensory characteristics can be achieved in fortified soymilk produced in small-scale batch processes with appropriate management of production and storage conditions.

A Prospective Study on the Relationship between Iron Supplement Intake, Hemoglobin Concentration, and Risk of Parkinsonism

The findings regarding whether the greater iron level or intake is a risk factor to Parkinson's disease (PD) or parkinsonism was not clear. The purpose of this study is to establish a consistent association between iron supplementation and parkinsonism risk, we conducted a large-scale prospective cohort study using comprehensive longitudinal data from the UK Biobank. The longitudinal cohort data of 385,898 participants (including 911 cases) who were middle to old aged British adults and joined the UK Biobank study from 2006 to 2010 and were followed up until 2018 was analyzed. The associations between iron supplement intake, hemoglobin levels and all cause subsequent parkinsonism risk after corrections of potential confounders (sex, age, household income, education length, employment status, deprivation level, body mass index, physical activity level, household numbers, smoking and drinking levels, health status, blood pressure) were investigated. Analyses revealed that (a) iron supplementation was significantly associated with higher parkinsonism risk, (b) greater hemoglobin was weakly and insignificantly associated with lower parkinsonism risk, and (c) multivitamin or vitamin C supplement intake was not significantly associated with parkinsonism risk. Regardless of whether the subjects were classified as anemic, normal, or polycythemic or in the hemoglobin level quintile, there was no nonlinear association between hemoglobin and parkinsonism risk. Parkinsonism risk did not differ between participants reporting supplementary iron intake with or without vitamin C or multivitamin supplement intake. Furthermore, polygenic risk score of PD negatively correlated with hemoglobin level, while it did not associate with intake of iron supplement or multivitamin or vitamin C supplement intake. The results suggest excessive iron intake may increase parkinsonism risk. Interventional studies are warranted to examine whether iron intake restriction is beneficial for individuals without clinical iron deficiency.

Vitamin C mitigates hematological and biochemical alterations caused by di(2-ethylhexyl) phthalate toxicity in female albino mice, Mus musculus

Di(2-ethylhexyl) phthalate (DEHP) is ubiquitous environmental contaminant and identified as endocrine-disrupting chemical (EDC), present in plastics as plasticizer. Due to its versatile use, human exposure level reaches to danger limit. The main focus of our study is to see the effect of vitamin C on hematological and biochemical alterations caused by Di(2-ethylhexyl) Phthalate toxicity in female albino mice, Mus musculus. It is found to cause defects of the liver, kidney, and lungs. Its anti-androgenic nature brings the main focus on its toxicity associated with reproductive and endocrine system. In this experimental study, 18 young female Swiss albino mice, Mus musculus, were used and divided into 3 groups of 6 animals each as control (corn oil vehicle), DEHP group (100 mg/kg body weight dissolved in corn oil), and DEHP + vitamin-C group (100 mg/kg body weight each, dissolved in corn oil and double distilled water, respectively) for 90 days. In this research, serum metabolites were evaluated to study the effect of DEHP on glucose, total protein, and lipid profile along with some hematological, enzymological, and oxidative stress parameters. Simultaneously, we compared the effectiveness of vitamin-C against DEHP toxicity to mitigate the serum homeostasis disturbance. In present study, we observed, in DEHP-treated animals, glucose, triglycerides, very-low-density lipoprotein (VLDL), total protein, alkaline phosphatase (ALP), acid phosphatase (ACP), and alanine aminotransferase (ALT) levels increased remarkably, whereas total cholesterol, high-density lipoproteins (HDL), aspartate aminotransferase (AST), total RBC count, total WBC count, and hemoglobin (Hb) level significantly decreased as compared to control group. In addition, we noticed there was a decrease in superoxide dismutase (SOD) and increase in levels of lipid peroxidation (MDA) and interleukin-6 (IL-6) in DEHP treatment group as compared to control group. The results indicated vitamin C had a better improving effect against DEHP toxicity on balancing metabolic abnormalities and inflammation-related comorbidities.

Iron Deficiency Anemia in Pregnancy

Anemia is defined as a low red blood cell count, a low hematocrit, or a low hemoglobin concentration. In pregnancy, a hemoglobin concentration of less than 11.0 g/dL in the first trimester and less than 10.5 or 11.0 g/dL in the second or third trimester (depending on the guideline used) is considered anemia. Anemia is the most common hematologic abnormality in pregnancy. Maternal anemia is associated with adverse fetal, neonatal and childhood outcomes, but causality is not established. Maternal anemia increases the likelihood of transfusion at delivery. Besides hemodilution, iron deficiency is the most common cause of anemia in pregnancy. The American College of Obstetricians and Gynecologists recommends screening for anemia with a complete blood count in the first trimester and again at 24 0/7 to 28 6/7 weeks of gestation. Mild anemia, with a hemoglobin of 10.0 g/dL or higher and a mildly low or normal mean corpuscular volume (MCV) is likely iron deficiency anemia. A trial of oral iron can be both diagnostic and therapeutic. Mild anemia with a very low MCV, macrocytic anemia, moderate anemia (hemoglobin 7.0-9.9 g/dL) or severe anemia (hemoglobin 4.0-6.9 g/dL) requires further investigation. Once a diagnosis of iron deficiency anemia is confirmed, first-line treatment is oral iron. New evidence suggests that intermittent dosing is as effective as daily or twice-daily dosing with fewer side effects. For patients with iron deficiency anemia who cannot tolerate, cannot absorb, or do not respond to oral iron, intravenous iron is preferred. With contemporary formulations, allergic reactions are rare.

Fabrication of Biopolymer Based Nanoparticles for the Entrapment of Chromium and Iron Supplements

The objective of this study was to encapsulate iron and chromium into novel nanoparticles formulated using chitosan (CS), dextran sulfate (DS) and whey protein isolate (WPI) for oral drug delivery. Empty and loaded CS-DS nanoparticles were prepared via complex coacervation whilst whey protein nanocarriers were produced by a modified thermal processing method using chitosan. The physiochemical properties of the particles were characterized to determine the effects of formulation variables, including biopolymer ratio on particle size and zeta potential. Permeability studies were also undertaken on the most stable whey protein–iron nanoparticles by measuring Caco-2 ferritin formation. A particle size analysis revealed that the majority of samples were sub-micron sized, ranging from 420–2400 nm for CS-DS particles and 220–1000 nm for WPI-CS samples. As expected, a higher chitosan concentration conferred a 17% more positive zeta potential on chromium-entrapped WPI nanoparticles, whilst a higher dextran volume decreased the size of CS-DS nanoparticles by 32%. The addition of iron also caused a significant increase in size for all samples, as seen where the loaded WPI samples were 296 nm larger than the empty particles. Caco-2 iron absorption revealed that one formulation, which had the lowest particle size (226 ± 10 nm), caused a 64% greater iron absorption compared to the ferrous sulfate standard. This study describes, for the first time, the novel design of chromium- and iron-entrapped nanoparticles, which could act as novel systems for oral drug delivery.

The Role of Intravenous Iron in the Treatment of Anemia Associated with Cancer and Chemotherapy

Cancer-related anemia (CRA) is a commonly occurring problem for patients with cancer regardless of whether they are receiving treatment with chemotherapy or immunotherapy. It may result from one or more processes (decreased production, increased destruction, or increased loss of red blood cells, RBC). Perturbations in iron availability form the primary basis for anemia in many patients with cancer-related anemia. Functional iron deficiency (FID) anemia is a condition in which the patient has adequate or increased iron stores, but this iron pool is not available for erythropoiesis. Erythropoiesis-stimulating agents (ESAs) were the original treatment for FID; over time, however, if the supply of iron cannot keep pace with increased RBC synthesis driven by ESAs, FID may eventually lead to the lack or loss of ESA responsiveness. Subsequent clinical trials reported that intravenous (IV) iron could enhance the erythropoietic response to ESAs. This chapter reviews the pathogenesis of FID and summarizes the literature on the treatment of cancer- and chemotherapy-induced anemia. Clinical trials using IV iron with or without ESAs are reviewed in addition to the currently available IV iron products. The consensus conclusions from these trials, as well as guideline recommendations, support the use of IV iron in these patients to enhance ESA responsiveness, decrease ESA dosage, and reduce RBC transfusions. Little data have been published on the long-term safety of IV iron or its impact on tumor growth. This paper also briefly explores novel approaches for the treatment of FID anemia, which has relevance in treating not only cancer patients but also patients with benign inflammatory disorders.

Vitamin C Content in Fruits: Biosynthesis and Regulation

Throughout evolution, a number of animals including humans have lost the ability to synthesize ascorbic acid (ascorbate, vitamin C), an essential molecule in the physiology of animals and plants. In addition to its main role as an antioxidant and cofactor in redox reactions, recent reports have shown an important role of ascorbate in the activation of epigenetic mechanisms controlling cell differentiation, dysregulation of which can lead to the development of certain types of cancer. Although fruits and vegetables constitute the main source of ascorbate in the human diet, rising its content has not been a major breeding goal, despite the large inter- and intraspecific variation in ascorbate content in fruit crops. Nowadays, there is an increasing interest to boost ascorbate content, not only to improve fruit quality but also to generate crops with elevated stress tolerance. Several attempts to increase ascorbate in fruits have achieved fairly good results but, in some cases, detrimental effects in fruit development also occur, likely due to the interaction between the biosynthesis of ascorbate and components of the cell wall. Plants synthesize ascorbate de novo mainly through the Smirnoff-Wheeler pathway, the dominant pathway in photosynthetic tissues. Two intermediates of the Smirnoff-Wheeler pathway, GDP-D-mannose and GDP-L-galactose, are also precursors of the non-cellulosic components of the plant cell wall. Therefore, a better understanding of ascorbate biosynthesis and regulation is essential for generation of improved fruits without developmental side effects. This is likely to involve a yet unknown tight regulation enabling plant growth and development, without impairing the cell redox state modulated by ascorbate pool. In certain fruits and developmental conditions, an alternative pathway from D-galacturonate might be also relevant. We here review the regulation of ascorbate synthesis, its close connection with the cell wall, as well as different strategies to increase its content in plants, with a special focus on fruits.

Dietary patterns, bone lead and incident coronary heart disease among middle-aged to elderly men

BACKGROUND

Most absorbed lead ends up in the bone, where it can be measured as a biomarker of cumulative exposure, elevations of which have been shown to predict a higher risk of coronary heart disease (CHD). Knowledge about the role of dietary patterns is critical to the development of effective interventions for the cardiovascular toxicity of cumulative lead exposure.

METHODS

594 men, free of CHD at baseline, were followed from August 1991 to June 2011 in the Normative Aging Study. Bone lead concentrations were measured by K-shell-X-ray fluorescence. Dietary patterns were identified using principal components analysis. Two dietary patterns were identified: a 'prudent' pattern characterized by high intake of fruit, vegetables, legumes, tomatoes, poultry, and seafood; and a 'Western' pattern, with high intake of red meat, processed meat, refined grains, high-fat dairy products, high-energy drinks, fries, butter and eggs. Cox proportional hazard models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. Effect modification on the multiplicative scale was examined through cross-product interaction terms.

RESULTS

137 men developed incident CHD events during 5071 person-years of follow-up. After adjusting for age, body mass index, total energy intake, smoking status, total cholesterol to high-density lipoprotein ratio, education and occupation, an HR of incident CHD was 1.64 (95% CI: 1.27-2.11) with each doubling in patella lead concentration in the low prudent diet group (< median prudent score); and the HR decreased to 1.07 (95% CI: 0.86-1.34) in the high prudent diet (≥ median prudent score) (p-for-interaction = 0.01), suggesting protective effects of prudent diet against lead-related CHD. By contrast, the association between tibia lead and CHD was non-significantly larger in the low Western diet group (HR = 1.43, 95% CI: 1.14-1.80) compared with the high Western diet group (HR = 1.08, 95% CI: 0.86-1.34) (p-for-interaction = 0.06). No significant effect modifications were detected by Western diet in the patella lead-CHD association and by prudent diet in the tibia lead-CHD association.

CONCLUSIONS

Prudent diet may reduce the risk of development of CHD in relation to patella lead. However, these findings need to be interpreted with caution, given the modest sample size.

Enzymatic treatment of pork protein for the enhancement of iron bioavailability

The typical intervention for iron-deficiency anaemia is through oral supplementation with iron salts, which have unpleasant side effects. Therefore, there is a need for the development of supplements which will be absorbed more effectively and may have fewer side effects. This study investigated the effects of partially hydrolysed pork proteins on the bioavailability of non-haem iron. The peptides were derived using either pepsin or a combination of bacterial and fungal proteases, and their ability to deliver iron was evaluated in a rat intestine epithelial tissue model. The greatest iron absorption was achieved with peptides hydrolysed by pepsin of low molecular weight (<6-8 kDa). The peptides hydrolysed with bacterial and fungal enzymes may have bound to the iron too strongly, affecting bioavailability. Finally, hydrolysing proteins using pepsin in the presence of iron produces a complex that resulted in more ferritin expression than mixing the peptides with iron after hydrolysis.

Assessing national nutrition security: The UK reliance on imports to meet population energy and nutrient recommendations

Nutrition security describes the adequacy of the food supply to meet not only energy but also macronutrient and micronutrient requirements for the population. The aim of this study was to develop a method to assess trends in national nutrition security and the contribution of imports to nutrition security, using the UK as a case study. Food supply data from FAO food balance sheets and national food composition tables were used to estimate the nutrient content of domestically produced food, imported food and exported food. Nutrition security was defined as the total nutrient supply (domestic production, minus exports, plus imports) to meet population-level nutrient requirements. The results showed that the UK was nutrition secure over the period 1961–2011 for energy, macronutrients and key micronutrients, with the exception of total carbohydrates and fibre, which may be due to the loss of fibre incurred by processing cereals into refined products. The supply of protein exceeded population requirements and could be met with domestic production alone. Even excluding all meat there was sufficient protein for population requirements. The supply of total fat, saturated fat and sugar considerably exceeded the current dietary recommendation. As regards nutrition security in 2010, the UK was reliant on imported foods to meet energy, fibre, total carbohydrate, iron, zinc and vitamin A requirements. This analysis demonstrates the importance of including nutrients other than energy to determine the adequacy of the food supply. The methodology also provides an alternative perspective on food security and self-sufficiency by assessing the dependency on imports to meet population level nutritional requirements.

Modern iron replacement therapy: clinical and pathophysiological insights

Iron deficiency, with or without anemia, is extremely frequent worldwide, representing a major public health problem. Iron replacement therapy dates back to the seventeenth century, and has progressed relatively slowly until recently. Both oral and intravenous traditional iron formulations are known to be far from ideal, mainly because of tolerability and safety issues, respectively. At the beginning of this century, the discovery of hepcidin/ferroportin axis has represented a turning point in the knowledge of the pathophysiology of iron metabolism disorders, ushering a new era. In the meantime, advances in the pharmaceutical technologies are producing newer iron formulations aimed at minimizing the problems inherent with traditional approaches. The pharmacokinetic of oral and parenteral iron is substantially different, and diversities have become even clearer in light of the hepcidin master role in regulating systemic iron homeostasis. Here we review how iron therapy is changing because of such important advances in both pathophysiology and pharmacology.

Increasing ascorbate levels in crops to enhance human nutrition and plant abiotic stress tolerance

Ascorbate (or vitamin C) is an essential human micronutrient predominantly obtained from plants. In addition to preventing scurvy, it is now known to have broader roles in human health, for example as a cofactor for enzymes involved in epigenetic programming and as regulator of cellular iron uptake. Furthermore, ascorbate is the major antioxidant in plants and underpins many environmentally induced abiotic stress responses. Biotechnological approaches to enhance the ascorbate content of crops therefore have potential to improve both human health and abiotic stress tolerance of crops. Identifying the genetic basis of ascorbate variation between plant varieties and discovering how some 'super fruits' accumulate extremely high levels of ascorbate should reveal new ways to more effectively manipulate the production of ascorbate in crops.

Vitamin C: the known and the unknown and Goldilocks

Vitamin C (Ascorbic Acid), the antiscorbutic vitamin, cannot be synthesized by humans and other primates, and has to be obtained from diet. Ascorbic acid is an electron donor and acts as a cofactor for fifteen mammalian enzymes. Two sodium-dependent transporters are specific for ascorbic acid, and its oxidation product dehydroascorbic acid is transported by glucose transporters. Ascorbic acid is differentially accumulated by most tissues and body fluids. Plasma and tissue vitamin C concentrations are dependent on amount consumed, bioavailability, renal excretion, and utilization. To be biologically meaningful or to be clinically relevant, in vitro and in vivo studies of vitamin C actions have to take into account physiologic concentrations of the vitamin. In this paper, we review vitamin C physiology; the many phenomena involving vitamin C where new knowledge has accrued or where understanding remains limited; raise questions about the vitamin that remain to be answered; and explore lines of investigations that are likely to be fruitful.

Management of gastroparesis-associated malnutrition

Gastroparesis (GP) is a chronic debilitating dysmotility characterized by unrelenting nausea, vomiting, bloating, early satiety, postprandial fullness and abdominal pain. Patients with GP experience other associated conditions, including gastroesophageal reflux disease, gastric bezoars and small bowel bacterial overgrowth. Furthermore, GP is associated with poor quality of life, increased emergency room visits, hospitalizations and subsequent increased healthcare costs. Currently, the managements of GP consist of glycemic control, antiemetics, prokinetics and the use of gastric electrical stimulation. However, most GP patients are at risk for significant nutritional abnormalities. As such, it is essential to screen and diagnose malnutrition in these patients. Poor oral intake in such patients could be supplemented by enteral tube feeding. Parenteral nutrition, although a last resort, is associated with a number of complications and should be used only for the short term. In summary, a systematic approach including initial nutritional screening, diet recommendations, medical therapy, nutritional re-evaluation and enteral and parental nutrition should be considered in complex GP patients.

Nutrient and plant secondary compound composition and iron-binding capacity in leaves and green stems of commonly used plant browse (Carolina willow; Salix caroliniana) fed to zoo-managed browsing herbivores

Plant secondary compounds are diverse structurally, and associated biological effects can vary depending on multiple factors including chemical structure and reaction conditions. Phenolic compounds such as tannins can chelate dietary iron, and supplementation of animal species sensitive to iron overload with tannins may prevent/treat iron overload disorder. We assessed the nutrient and phenolic composition and iron-binding capacity of Carolina willow (Salix caroliniana), a plant fed to zoo-managed browsing herbivores. Based on studies in other plant species and the chemical structures of phenolic compounds, we hypothesized that the concentration of condensed tannins in willow would be inversely related to the concentration of phenolic glycosides and directly related to iron-binding capacity. Our results indicated that willow nutrient composition varied by year, season, and plant part, which could be taken into consideration when formulating animal diets. We also found that the predominant plant secondary compounds were condensed tannins with minimal phenolic glycosides. Instead of binding to iron, the willow leaf extracts reduced iron from the ferric to ferrous form, which may have prooxidative effects and increase the bioavailability of iron depending on animal species, gastrointestinal conditions, and whole animal processes. We recommend identifying alternative compounds that effectively chelate iron in vitro and conducting chelation therapy trials in vivo to assess potential effects on iron balance and overall animal health.

[Approach to the diagnosis and treatment of chronic anemia secondary to gastrointestinal diseases]

Iron deficiency anemia is the most common type of anemia and can cause asthenia, cognitive and functional impairment, and decompensation of underlying diseases. Iron deficiency anemia is not a disease but is the result of a potentially serious medical problem. Consequently, patients should always undergo investigation of the underlying cause. In men and postmenopausal women, the condition is caused by gastrointestinal loss and malabsorption of iron. In this group, recommended procedures are gastroscopy, colonoscopy and serological testing for celiac disease. If the results of these tests are negative, repeat examinations and iron therapy should be considered. In treatment-refractory or recurrent anemia, the small intestine should be investigated. In this case, the procedure of choice is capsule endoscopy. Iron deficiency anemia should always be treated until iron deposits have returned to normal levels. A wide variety of preparations are available, in both oral and parental formulations.

Brassica foods as a dietary source of vitamin C: a review

Brassica genus includes known horticultural vegetables with major economical importance worldwide, and involves vegetables of economical importance being part of the diet and source of oils for industry in many countries. Brassicales own a broad array of health-promoting compounds, emphasized as healthy rich sources of vitamin C. The adequate management of pre- and postharvest factors including crop varieties, growth conditions, harvesting, handling, storage, and final consumer operations would lead to increase or preserve of the vitamin C content or reduced losses by interfering in the catalysis mechanisms that remains largely unknown, and should be reviewed. Likewise, the importance of the food matrix on the absorption and metabolism of vitamin C is closely related to the range of the health benefits attributed to its intake. However, less beneficial effects were derived when purified compounds were administered in comparison to the ingestion of horticultural products such as Brassicas, which entail a closely relation between this food matrix and the bioavailability of its content in vitamin C. This fact should be here also discussed. These vegetables of immature flowers or leaves are used as food stuffs all over the world and represent a considerable part of both western and non-Western diets, being inexpensive crops widely spread and reachable to all social levels, constituting an important source of dietary vitamin C, which may work synergistically with the wealth of bioactive compounds present in these foods.

Food Insecurity Experiences Predict Children's Fruit and Vegetable Consumption in the USA

This research analyses the longitudinal relationships between household food insecurity (very low and low food security) experiences and children's consumption (servings/week) of fruit, green salad, carrots, potatoes, and other types of vegetables. Using a panel of 5,670 children aged 10–13 years who were first observed in spring 2004 and then again in spring 2007 at age 13–16 years, the main findings are as follows: first, children experiencing low food security consume significantly (P < 0.05) more fruit per week. In contrast, children experiencing very low food security consume significantly more carrots and potatoes per week, and estimates based on gender-stratified models indicate that the association is strongest among girls. Second, activity patterns are significantly related to children's dietary patterns; physical exercise is positively associated with fruit, green salad, carrot, and other vegetables consumption, while television watching is positively associated with potato consumption. Overall, the findings suggest that children living in food insecure home environments consume a greater number of servings of fruits and vegetables per week, relative to children living in food secure home environments.

Obesity, bariatric surgery, and iron deficiency: true, true, true and related

Morbid obesity is a health problem that has been shown to be refractory to diet, exercise, and medical treatment. Surgeries designed to promote weight loss, termed bariatric surgery and typically involving a gastric bypass procedure, have recently been implemented to treat obesity with high success rates. However, long-term sequelae can result in micronutrient deficiencies. This review will focus on iron deficiency and its association with obesity and bariatric surgery. Iron deficiency develops after gastric bypass for several reasons including intolerance for red meat, diminished gastric acid secretion, and exclusion of the duodenum from the alimentary tract. Menstruating women, pregnant women, and adolescents may be particularly predisposed toward developing iron deficiency and microcytic anemias after bypass surgery. Preoperative assessment of patients should include a complete hematological work-up, including measurement of iron stores. Postoperatively, oral iron prophylaxis and vitamin C in addition to a multivitamin should be prescribed for bypass patients, especially for vulnerable populations. Once iron deficiency has developed, it may prove refractory to oral treatment, and require parenteral iron, blood transfusions, or surgical interventions. Bariatric surgery patients require lifelong follow-up of hematological and iron parameters since iron deficiency and anemia may develop years after surgery.

Obscure gastrointestinal bleeding: diagnostic and therapeutic approach

Obscure gastrointestinal bleeding (OGIB) is defined as an intermittent or continuous loss of blood in which the source has not been identified after upper endoscopy and colonoscopy. It constitutes a diagnostic and therapeutic challenge for the general internist and the gastroenterologist. This article provides an overview of the etiology, clinical presentation, and diagnostic modalities of OGIB including push enteroscopy, double balloon enteroscopy, wireless capsule endoscopy, enteroclysis, angiography, bleeding scanning with labeled red blood cells, and surgery with intraoperative enteroscopy. Therapeutic modalities including iron replacement, combined hormones, octreotide acetate, therapeutic endoscopy, and surgery are also discussed. In addition, a rational approach to patients with OGIB according to the clinical presentation is presented herein.

Associations of iron status with dietary and other factors in 6-year-old children

OBJECTIVE

To investigate the associations of iron status at 6 years of age with dietary and other factors.

DESIGN

In a cross-sectional study, children's dietary intakes (3-day weighed food record) were recorded, body size was measured and blood samples were taken near their sixth birthday.

SUBJECTS

A sample of 188 children, from two previous studies (cohorts 1 and 2), was contacted, and 139 (74%) agreed to participate.

RESULTS

Multiple regression analyses with dietary and other factors showed that meat and fish consumption, multivitamin/mineral supplement intake (both positively) and cow's milk product consumption (negatively) were associated with log serum ferritin (SF) (adjusted R (2)=0.125; P=0.028; n=129), and juices and residence (rural>urban) with haemoglobin (Hb) (adjusted R (2)=0.085; P=0.034; n=127). Of 21 multivitamin/mineral consumers, none had depleted iron stores compared to 21 iron-depleted of 108 non-consumers (P=0.024). Children living in rural areas (<10,000 inhabitants) (n=33) had higher mean corpuscular volume (MCV) (83.3+/-2.3 fl) than those living in urban areas (>10,000 inhabitants) (82.1+/-3.2 fl; n=103) (P=0.048). Multiple regression analyses with dietary and other factors and growth showed in cohort 1 that residence (rural>urban), weight gain 0-1years (negatively), and meat and fish intake (positively) were associated with Hb (adjusted R (2)=0.323; P=0.030; n=51), meat and fish (positively) with both log SF (adjusted R (2)=0.069; P=0.035; n=52) and MCV (adjusted R (2)=0.064; P=0.035; n=52), and in cohort 2 cow's milk product consumption (negatively) was associated with log SF (adjusted R (2)=0.119; P=0.017; n=41) and residence (rural>urban) with MCV (adjusted R (2)=0.102; P=0.025; n=41).

CONCLUSIONS

Consumption of meat and fish and possibly also juices, as well as multivitamin/mineral intake might affect iron status in 6-year-old children positively, whereas cow's milk product consumption might affect iron status negatively. Slower growth in the first year of life and rural residence are positively related to iron status of 6-year-olds.

Management of iron deficiency in patients admitted to hospital: time for a rethink of treatment principles

BACKGROUND

Iron deficiency is very common in patients admitted to hospital. Its management is changing with new insights into iron absorption and therapeutic options.

AIMS

The aims of this study were to develop guidelines for the correction of iron deficiency in patients admitted to hospital and to compare these with current practice.

METHODS

Based on current published evidence, guidelines were developed. All patients in whom iron deficiency was detected during hospital admission over a 2.5 year period were retrospectively studied. Their management was compared with that of the guidelines developed.

RESULTS

Three clinical scenarios were identified--(A) urgent attention to haemoglobin required: blood transfusion followed by i.v. iron recommended, (B) Semiurgent iron repletion: i.v. iron recommended and (C) non-urgent iron repletion: oral or i.v. repletion recommended. A total of 119 patients was identified, age 18-99 (median 77) years, 29% men, and haemoglobin 33-130 (87) g/L. Of 66 given blood transfusion, 17 had subsequent i.v. iron, 25 oral iron and 24 no other form of iron repletion. Of the other 53, nine had i.v. iron, 32 oral iron and 12 had no treatment. Fifty-five per cent of patients were managed according to the proposed guidelines and this occurred less frequently (9%) in those presenting with cardiovascular problems than in those with anaemia, gastrointestinal bleeding or other medical problems (all >60%; P < 0.0001, Fisher's exact test).

CONCLUSION

Current management is haphazard, with underutilization of i.v. iron and failure to initiate any regimen for iron repletion being common. It may be time for a change in approach to repletion of iron in ill patients.

Exploiting intracellular iron and iron-rich compounds to effect tumor cell lysis

The regimen outlined in this brief paper focuses on therapeutically utilizing iron and iron compounds in transferrin receptor-rich tumor cells in ways that inhibit and lyse same.

Iron status at 12 months of age -- effects of body size, growth and diet in a population with high birth weight

OBJECTIVE

To investigate effects of growth and food intake in infancy on iron status at the age of 12 months in a population with high birth weight and high frequency of breast-feeding.

DESIGN

In a longitudinal observational study infants' consumption and growth were recorded. Weighed 2 day food records at the ages of 6, 9 and 12 months were used to analyse food and nutrient intake.

SETTING

Healthy-born participants were recruited from four maternity wards. Blood samples and growth data were collected from healthcare centres and food consumption data at home.

SUBJECTS

Newborn infants (n=180) were selected randomly according to the mother's domicile and 77% (n=138) participated, of them, 83% (n=114), or 63% of original sample, came in for blood sampling.

RESULTS

Every fifth child was iron-deficient (serum ferritin <12 microg/l and mean corpuscular volume<74 fl) and 2.7% were also anaemic (Hb<105 g/l). Higher weight gain from 0 to 12 months was seen in infants who were iron-deficient at 12 months (6.7+/-0.9 kg) than in non-iron-deficient infants (6.2+/-0.9 kg) (P=0.050). Serum transferrin receptors at 12 months were positively associated with length gain from 0 to 12 months (adjusted r(2)=0.14; P=0.045) and mean corpuscular volume negatively to ponderal index at birth (adjusted r(2)=0.14; P=0.019) and 12 months (adjusted r(2)=0.17; P=0.006). Iron-deficient infants had shorter breast-feeding duration (5.3+/-2.2 months) than non-iron-deficient (7.9+/-3.2 months; P=0.001). Iron status indices were negatively associated with cow's milk consumption at 9-12 months, significant above 460 g/day, but were positively associated with iron-fortified breakfast cereals, fish and meat consumption.

CONCLUSIONS

: In a population of high birth weight, iron deficiency at 12 months is associated with faster growth and shorter breast-feeding duration from 0 to 12 months of age. The results suggest that a diet of 9-12-month-olds should avoid cow's milk above 500 g/day and include fish, meat and iron-fortified breakfast cereals to improve iron status.

Vitamin C as an antioxidant: evaluation of its role in disease prevention

Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage.

Molecular and functional roles of duodenal cytochrome B (Dcytb) in iron metabolism

Dcytb has been identified as the mammalian transplasma ferric reductase that catalyzes the reduction of ferric to ferrous iron in the process of iron absorption. Its mRNA and protein levels are up-regulated by several independent stimulators of iron absorption. Furthermore, its cDNA encodes putative binding sites for heme and ascorbic acid. Using Northern and Western blots, RT-PCR and confocal microscopy, we studied the expression and localisation of Dcytb in cell lines and tissues of CD1 mice. Dcytb expression and function were modulated by iron. Dcytb and DMT1, both predominantly localised in the apical region of the duodenum were up-regulated in iron deficiency. Dcytb, the iron regulated ferric reductase may also utilize cytoplasmic ascorbate as electron donor for transmembrane reduction of iron. Dcytb expression was found in other tissues apart from the duodenum and its regulation and functions at these other sites are of interest in iron metabolism.

Vitamin C inhibits NF-kappa B activation by TNF via the activation of p38 mitogen-activated protein kinase

The transcription factor NF-kappaB is a central mediator of altered gene expression during inflammation, and is implicated in a number of pathologies, including cancer, atherosclerosis, and viral infection. We report in this study that vitamin C inhibits the activation of NF-kappaB by multiple stimuli, including IL-1 and TNF in the endothelial cell line ECV304 and in primary HUVECs. The induction of a NF-kappaB-dependent gene, IL-8, by TNF was also inhibited. The effect requires millimolar concentrations of vitamin C, which occur intracellularly in vivo, particularly during inflammation. Vitamin C was not toxic to cells, did not inhibit another inducible transcription factor, STAT1, and had no effect on the DNA binding of NF-kappaB. Inhibition by vitamin C was not simply an antioxidant effect, because redox-insensitive pathways to NF-kappaB were also blocked. Vitamin C was shown to block IL-1- and TNF-mediated degradation and phosphorylation of I-kappaBalpha (inhibitory protein that dissociates from NF-kappaB), due to inhibition of I-kappaB kinase (IKK) activation. Inhibition of TNF-driven IKK activation was mediated by p38 mitogen-activated protein kinase, because treatment of cells with vitamin C led to a rapid and sustained activation of p38, and the specific p38 inhibitor SB203580 reversed the inhibitory effect of vitamin C on IKK activity, I-kappaBalpha phosphorylation, and NF-kappaB activation. The results identify p38 as an intracellular target for high dose vitamin C.

The role of vitamins in the prevention and control of anaemia

OBJECTIVE

While iron deficiency is regarded as the major cause of nutritional anaemia, changes in vitamins A, B12, C and E, folic acid and riboflavin status have also been linked to its development and control. This paper provides a systematic review of vitamin supplementation trials relating to the control of nutritional anaemia.

METHODS

A MEDLINE search was used to find reports of vitamin supplementation trials that reported changes in anaemia or iron status.

RESULTS

Vitamin A can improve haematological indicators and enhance the efficacy of iron supplementation. Both folate and vitamin B12 can cure and prevent megaloblastic anaemia. Riboflavin enhances the haematological response to iron, and its deficiency may account for a significant proportion of anaemia in many populations. Vitamin C enhances the absorption of dietary iron, although population-based data showing its efficacy in reducing anaemia or iron deficiency are lacking. Vitamin E supplementation given to preterm infants has not reduced the severity of the anaemia of prematurity. Vitamin B6 effectively treats sideroblastic anaemia. Multivitamin supplementation may raise haemoglobin (Hb) concentration, but few studies have isolated the effect of multivitamins from iron on haematological status.

CONCLUSIONS

In general, the public health impact of vitamin supplementation in controlling anaemia is not clear. Neither are the complex interactions involving multiple vitamins in haematopoiesis sufficiently understood to explain the observed variability in haematological responses to vitamins by age, population, vitamin mixture and dosages. Further research is needed to understand the roles of individual and combined vitamin deficiencies on anaemia to design appropriate micronutrient interventions to prevent anaemia.

Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians

Dietary and nutritional status of individuals habitually consuming a vegan diet was evaluated by biochemical, hematologic, and immunologic measures in comparison with a nonvegetarian group. On the basis of 4-d dietary records, the intake of female and male vegans tended to be lower in fat, saturated fat, monounsaturated fat, and cholesterol and higher in dietary fiber than that of vegetarians. With computed food and supplement intakes, vegan diets provided significantly higher amounts of ascorbate, folate, magnesium, copper, and manganese in both female and male participants. The body mass index (BMI; in kg/m(2)) of the vegans was significantly lower than that of the nonvegetarians and 9 of the 25 vegans had a BMI <19. Serum ferritin concentrations were significantly lower in vegan men but iron and zinc status did not differ between the sexes. Mean serum vitamin B-12 and methylmalonic acid concentrations did not differ; however, 10 of the 25 vegans showed a vitamin B-12 deficit manifested by macrocytosis, circulating vitamin B-12 concentrations <150 pmol/L, or serum methylmalonic acid >376 nmol/L. Vegans had significantly lower leukocyte, lymphocyte, and platelet counts and lower concentrations of complement factor 3 and blood urea nitrogen but higher serum albumin concentrations. Vegans did not differ from nonvegetarians in functional immunocompetence assessed as mitogen stimulation or natural killer cell cytotoxic activity.

Effects of Iron Supplementation on Iron Nutrition Status and Cognitive Functions in Children

This study examined the effect of iron supplementation on cognitive function by a double-blind intervention trial in nine-year-old mildly anaemic schoolchildren. Their nutritional status was assessed by anthropometric measurements and the following biochemical values: haemoglobin, haematocrit, red blood cell count (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), serum iron, total iron-binding capacity (TIBC), and transferrin saturation. In addition, biochemical values of vitamin A, vitamin C, thiamine, riboflavin, pyridoxine, and zinc were measured. The cognitive assessment was performed using an abbreviated Wechsler Intelligence Scale for Children-Revised (WISC-R) containing six subtests: arithmetic, similarities, digit span, picture completion, block design, and digit symbol (coding), in order to obtain information on both verbal and non-verbal aspects of intelligence. There were highly significant correlations of the WISC-R scores with initial height-for-age, haemoglobin, haematocrit, and transferrin saturation, and a correlation with MCHC. After completion of the baseline examination, one group of children was given a supplement containing 100 mg of iron for 10 weeks while the other group received a placebo. Iron supplementation had a positive effect on the biochemical measures of iron status, with haemoglobin, haematocrit, transferrin saturation, RBC, MCH, and MCHC all showing statistically significant increases ( p < .05). Iron supplementation also resulted in a statistically significant improvement in total WISC-R score ( p < .01). This effect was primarily the result of improved performance on nonverbal subtests, of which improvements in block design and coding were statistically significant ( p < .01). The small increase in the sum of scaled scores from the verbal subtest was not significant ( p > .05), but within the verbal subtest there was a significant improvement on the similarities part of the test ( p < .05). The effects of iron supplementation were more pronounced in children with initially lower haemoglobin values. It is concluded that iron supplementation in nine-year-old schoolchildren with haemoglobin levels between 110 and 119 g/L will result in an improvement of cognitive functions, even though they are not otherwise malnourished.

Influence of vegetarian and mixed nutrition on selected haematological and biochemical parameters in children

To evaluate the health and nutritional status of children with two different nutritional habits, the authors examined 26 vegetarians (lacto- and lacto-ovo; an average period of vegetarianism 2.8 years) and 32 individuals on mixed diet (omnivores) in the age range 11-14 years. Vegetarian children had significantly lower erythrocyte number as well as reduced levels of haemoglobin and iron compared to omnivores. The average level of iron did not reach the lower limit of the physiological range and hyposiderinemia was found in 58% of vegetarians vs 9% of omnivores. Reduced iron levels were observed in spite of increased intake of vegetable iron sources and vitamin C (which facilitates the conversion to ferro-form). This reduction can be attributed to the absence of animal iron sources with high utilizability and to lower iron utilization in the presence of phytic acid (higher intake of grains compared to omnivores). The incidence of hypoalbuminemia and hypoproteinemia in vegetarian children was 38 and 12%, respectively, compared to 0% in omnivores. The protein mixture from milk, eggs and vegetable sources is complete, but vegetarian children had significantly reduced intake of milk and dairy products. Favourable lipid and antioxidant parameters in vegetarian children reflect the optimal nutrition composition with respect to the prevention of free radical diseases. Such a nutrition results in significantly lower levels of cholesterol and LDL-cholesterol compared to omnivores and significantly higher and over threshold values of essential antioxidants--vitamin C, vitamin E/cholesterol (more effective protection against LDL oxidation), beta-carotene, vitamin A.

Effects of intestinal resection, cholecalciferol and ascorbic acid on iron metabolism in rats

The effect of dietary supplementation with ascorbic acid or cholecalciferol on Fe utilization was studied using the metabolic balance technique, in rats in which 50% of the distal small intestine was removed, or in which the mid small intestine was transected and reanastomosed (controls). Three different diets were used. The first (basal diet) contained (g/kg dry wt): protein (casein + 50 mg D,L-methionine/g) 120 and fat (medium-chain triacylglycerols, olive oil and sunflower oil, in equal parts) 40. The other diets were obtained by adding ascorbic acid (150 mg/kg diet) or cholecalciferol (0.4 mg/kg diet) to the basal diet. Apparent digestibility coefficient (ADC) and Fe retention were significantly lower in resected animals than in their respective control groups (transected rats). However, the addition of ascorbic acid or cholecalciferol to the basal diet increased the ADC and Fe retention in both transected and resected rats. Five weeks after surgery, resection also resulted in a reduced concentration of Fe in the sternum, but did not reduce the concentration of haemoglobin or serum Fe total Fe-binding capacity or the concentration of Fe in liver, testes, femur or muscle (longissimus dorsi). Supplementation with ascorbic acid increased serum Fe concentration, while the concentration of Fe in muscle was reduced by supplementation with both ascorbic acid and cholecalciferol. Neither supplementation had any effect on the Fe concentration in other tissues, on haemoglobin concentration or plasma total Fe-binding capacity. Thus, supplementation with ascorbic acid or with cholecalciferol increased Fe absorption and reduced the concentration of Fe in muscle.

Vitamin C (ascorbic acid): new roles, new requirements?

There is an enormous amount of literature on vitamin C intake and health in animals, cell cultures, and humans. Beyond its function in collagen formation, ascorbic acid is known to increase absorption of inorganic iron, to have essential roles in the metabolism of folic acid and of some amino acids and hormones, and to act as an antioxidant. In recent years, research has increasingly focused on this latter function, stimulated by suggestions that "oxidative stress" may be a causal factor in the etiology of such diverse and important disorders of aging as cancer, cardiovascular disease, and cataract formation. The present evidence is strong enough to have convinced nutritionists that daily vitamin C intake should be many times higher than the amount needed to protect against scurvy, and this is reflected in the present Recommended Dietary Allowances. Suggestions that the recommended levels should be higher still are largely based on extrapolations from results of animal and tissue culture studies. How much ascorbic acid is necessary to achieve in humans the effects seen in animal studies is not clear. In general, the limited human studies have not been persuasive. The data are incomplete, and many of the studies have serious flaws. There are no toxicity studies of the type done for new compounds being considered for approval as therapy for major disease conditions. Intervention studies will be difficult, but are essential, and methods for tissue saturation measurement must be defined before new recommendations for the public are designed.

Treatment of iron-deficiency anemia complicated by scurvy and folic acid deficiency

We present a case of a child with iron-deficiency anemia, folic acid deficiency, and scurvy. His anemia proved refractory to treatment with iron until he received both folic acid and vitamin C supplementation. This case illustrates the importance of the evaluation of ascorbic acid and folate status in treating iron-deficiency anemia initially refractory to iron supplementation, because multiple nutrient deficiencies may coexist.

The importance of reductive mechanisms for intestinal uptake of iron from ferric maltol and ferric nitrilotriacetic acid (NTA)

Intestinal iron absorption is thought to proceed with iron mainly in the ferrous form, yet the novel iron complex, ferric maltol is an effective oral preparation. Although possessing a high oil: water partition coefficient, ferric maltol does not diffuse across the intestine but donates its iron to the endogenous uptake system. Reduction of the ferric iron in the gut lumen appears to precede iron uptake both from ferric maltol and from ferric nitrilotriacetic acid (NTA) which is a non-penetrating iron ligand. Uptake of radiolabelled iron (59Fe) into isolated fragments of rat small intestine was inhibited by the ferrous chelator, bathophenanthroline sulphonate (BPS) and enhanced at low concentrations by the reducing agent ascorbic acid. Spectrophotometric evidence was obtained that ferrous ions are generated from these ferric complexes in the presence of ascorbic acid and other reducing agents. The rate of ferrous ion formation was independent of ferric maltol concentration at low ascorbic acid levels and decreased with increasing ferric maltol concentration at higher levels of ascorbate. Maltol has a high affinity for ferric ions and may delay reduction at higher concentrations. By contrast, a higher rate of ferrous ion generation was seen with ferric NTA and this increased with iron ligand concentration. Washings from the intestinal lumen also brought about ferrous ion formation from these ferric ligands. Gel filtration revealed these reducing factors to be of low molecular weight. The washings, however, interfered with 59Fe uptake into the isolated fragments, but when reducing fractions only from the filtered washings were used, enhanced iron uptake was seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascorbic acid safety: analysis of factors affecting iron absorption

The potential for excessive iron absorption by subjects ingesting ascorbic acid doses above the recommended dietary allowance (60 mg) was evaluated by examining published literature (24 studies, 1412 subjects) in which ascorbic acid was part of a test meal given to determine effects on iron absorption. Three parameters associated with iron absorption were identified: (1) a relatively shallow slope for the dose-response curve relating ascorbic acid dosage (1-1000 mg) and percent iron absorption; (2) no significant effect of ascorbic acid on the absorption of high (60 mg) iron doses; and (3) an inverse relationship between iron absorption and plasma transferrin saturation. Ascorbic acid did not increase the incidence of 'high' iron absorbers (greater than 2 SD from population mean) above control levels; limited data for ascorbic acid doses greater than 100 mg/d indicated no change in the distribution of iron absorption values.