Riboflavin status in infants born in rural Gambia, and the effect of a weaning food supplement

Causes and Clinical Sequelae of Riboflavin Deficiency

Riboflavin, in its cofactor forms flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), plays fundamental roles in energy metabolism, cellular antioxidant potential, and metabolic interactions with other micronutrients, including iron, vitamin B6, and folate. Severe riboflavin deficiency, largely confined to low-income countries, clinically manifests as cheilosis, angular stomatitis, glossitis, seborrheic dermatitis, and severe anemia with erythroid hypoplasia. Subclinical deficiency may be much more widespread, including in high-income countries, but typically goes undetected because riboflavin biomarkers are rarely measured in human studies. There are adverse health consequences of low and deficient riboflavin status throughout the life cycle, including anemia and hypertension, that could contribute substantially to the global burden of disease. This review considers the available evidence on causes, detection, and consequences of riboflavin deficiency, ranging from clinical deficiency signs to manifestations associated with less severe deficiency, and the related research, public health, and policy priorities.

COVID-19 Outbreak: Pathogenesis, Current Therapies, and Potentials for Future Management

At the end of 2019, a novel coronavirus (CoV) was found at the seafood market of Hubei province in Wuhan, China, and this virus was officially named coronavirus diseases 2019 (COVID-19) by World Health Organization (WHO). COVID-19 is mainly characterized by severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) and creates public health concerns as well as significant threats to the economy around the world. Unfortunately, the pathogenesis of COVID-19 is unclear and there is no effective treatment of this newly life-threatening and devastating virus. Therefore, it is crucial to search for alternative methods that alleviate or inhibit the spread of COVID-19. In this review, we try to find out the etiology, epidemiology, symptoms as well as transmissions of this novel virus. We also summarize therapeutic interventions and suggest antiviral treatments, immune-enhancing candidates, general supplements, and CoV specific treatments that control replication and reproduction of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV).

Riboflavin Depletion Promotes Tumorigenesis in HEK293T and NIH3T3 Cells by Sustaining Cell Proliferation and Regulating Cell Cycle-Related Gene Transcription

BACKGROUND

Riboflavin is an essential component of the human diet and its derivative cofactors play an established role in oxidative metabolism. Riboflavin deficiency has been linked with various human diseases.

OBJECTIVE

The objective of this study was to identify whether riboflavin depletion promotes tumorigenesis.

METHODS

HEK293T and NIH3T3 cells were cultured in riboflavin-deficient or riboflavin-sufficient medium and passaged every 48 h. Cells were collected every 5 generations and plate colony formation assays were performed to observe cell proliferation. Subcutaneous tumorigenicity assays in NU/NU mice were used to observe tumorigenicity of riboflavin-depleted HEK293T cells. Mechanistically, gene expression profiling and gene ontology analysis were used to identify abnormally expressed genes induced by riboflavin depletion. Western blot analyses, cell cycle analyses, and chromatin immunoprecipitation were used to validate the expression of cell cycle-related genes.

RESULTS

Plate colony formation of NIH3T3 and HEK293T cell lines was enhanced >2-fold when cultured in riboflavin-deficient medium for 10-20 generations. Moreover, we observed enhanced subcutaneous tumorigenicity in NU/NU mice following injection of riboflavin-depleted compared with normal HEK293T cells (55.6% compared with 0.0% tumor formation, respectively). Gene expression profiling and gene ontology analysis revealed that riboflavin depletion induced the expression of cell cycle-related genes. Validation experiments also found that riboflavin depletion decreased p21 and p27 protein levels by ∼20%, and increased cell cycle-related and expression-elevated protein in tumor (CREPT) protein expression >2-fold, resulting in cyclin D1 and CDK4 levels being increased ∼1.5-fold, and cell cycle acceleration. We also observed that riboflavin depletion decreased intracellular riboflavin levels by 20% and upregulated expression of riboflavin transporter genes, particularly SLC52A3, and that the changes in CREPT and SLC52A3 correlated with specific epigenetic changes in their promoters in riboflavin-depleted HEK293T cells.

CONCLUSION

Riboflavin depletion contributes to HEK293T and NIH3T3 cell tumorigenesis and may be a risk factor for tumor development.

Limitations of the Evidence Base Used to Set Recommended Nutrient Intakes for Infants and Lactating Women

Reported values for concentrations of micronutrients in human milk form the basis of the majority of micronutrient intake recommendations for infants and the additional maternal requirements for lactation. The infant recommendations may also be extrapolated to provide estimates for young children. The purpose of this review is to evaluate the adequacy of the milk micronutrient concentration data used by the Institute of Medicine to set recommendations for the United States and Canada, by FAO/WHO, the United Kingdom, and the European Food Safety Authority. The concentrations accepted by each agency are presented for each micronutrient accompanied by the source of information and comments on the number, location, status, and stage of lactation of the sample population, where known. These summaries show the small number of participants from which samples were collected in most studies, the wide range of concentrations within studies, the lack of longitudinal data, and the variability in collection methods. These factors contribute to the variability in nutrient intake recommendations among committees, although this variability is reduced by some committees that accept milk-composition values proposed by others. Values are also summarized from milk collected in studies in which mothers or infants were known to be deficient on the basis of clinical symptoms, biomarkers of inadequacy, or both, to show the extent to which milk micronutrients can be reduced by poor maternal nutritional status. We conclude that a new, multicenter study is needed to establish reference values for milk constituents across lactation.

Dietary Reference Values for riboflavin

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for riboflavin. The Panel considers that the inflection point in the urinary riboflavin excretion curve in relation to riboflavin intake reflects body saturation and can be used as a biomarker of adequate riboflavin status. The Panel also considers that erythrocyte glutathione reductase activation coefficient is a useful biomarker, but has limitations. For adults, the Panel considers that average requirements (ARs) and population reference intakes (PRIs) can be determined from the weighted mean of riboflavin intake associated with the inflection point in the urinary riboflavin excretion curve reported in four intervention studies. PRIs are derived for adults and children assuming a coefficient of variation of 10%, in the absence of information on the variability in the requirement and to account for the potential effect of physical activity and the methylenetetrahydrofolate reductase 677TT genotype. For adults, the AR and PRI are set at 1.3 and 1.6 mg/day. For infants aged 7–11 months, an adequate intake of 0.4 mg/day is set by upward extrapolation from the riboflavin intake of exclusively breastfed infants aged 0–6 months. For children, ARs are derived by downward extrapolation from the adult AR, applying allometric scaling and growth factors and considering differences in reference body weight. For children of both sexes aged 1–17 years, ARs range between 0.5 and 1.4 mg/day, and PRIs between 0.6 and 1.6 mg/day. For pregnant or lactating women, additional requirements are considered, to account for fetal uptake and riboflavin accretion in the placenta during pregnancy or the losses through breast milk, and PRIs of 1.9 and 2.0 mg/day, respectively, are derived.

This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1268/full

Analyzing B-vitamins in Human Milk: Methodological Approaches

According to the World Health Organization (WHO), infants should be exclusively breastfed for the first six months of life. However, there is insufficient information about the concentration of nutrients in human milk. For some nutrients, including B-vitamins, maternal intake affects their concentration in human milk but the extent to which inadequate maternal diets affect milk B-vitamin content is poorly documented. Little is known about infant requirements for B-vitamins; recommendations are generally set as Adequate Intakes (AI) calculated on the basis of the mean volume of milk (0.78 L/day) consumed by infants exclusively fed with human milk from well-nourished mothers during the first six months, and the concentration of each vitamin in milk based on reported values. Methods used for analyzing B-vitamins, commonly microbiological, radioisotope dilution or more recently chromatographic, coupled with UV, fluorometric and MS detection, have rarely been validated for the complex human milk matrix. Thus the validity, accuracy, and sensitivity of analytical methods is important for understanding infant requirements for these nutrients, the maternal intakes needed to support adequate concentrations in breast milk. This review summarizes current knowledge on methods used for analyzing the B-vitamins thiamin, riboflavin, niacin, vitamin B-6 and pantothenic acid, vitamin B-12, folate, biotin, and choline in human milk, their chemical and physical properties, the different forms and changes in concentration during lactation, and the effects of deficiency on the infant.

Riboflavin status, MTHFR genotype and blood pressure: current evidence and implications for personalised nutrition

Clinical deficiency of the B-vitamin riboflavin (vitamin B2) is largely confined to developing countries; however accumulating evidence indicates that suboptimal riboflavin status is a widespread problem across the developed world. Few international data are available on riboflavin status as measured by the functional biomarker, erythrocyte glutathione reductase activation coefficient, considered to be the gold standard index. One important role of riboflavin in the form of flavin dinucleotide is as a co-factor for the folate-metabolising enzyme methylenetetrahydrofolate reductase (MTHFR). Homozygosity for the common C677T polymorphism in MTHFR, affecting over 10 % of the UK and Irish populations and up to 32 % of other populations worldwide, has been associated with an increased risk of CVD, and more recently with hypertension. This review will explore available studies reporting riboflavin status worldwide, the interaction of riboflavin with the MTHFR C677T polymorphism and the potential role of riboflavin in personalised nutrition. Evidence is accumulating for a novel role of riboflavin as an important modulator of blood pressure (BP) specifically in individuals with the MTHFR 677TT genotype, with results from a number of recent randomised controlled trials demonstrating that riboflavin supplementation can significantly reduce systolic BP by 5-13 mmHg in these genetically at risk adults. Studies are however required to investigate the BP-lowering effect of riboflavin in different populations and in response to doses higher than 1·6 mg/d. Furthermore, work focusing on the translation of this research to health professionals and patients is also required.

Supplementation with multiple micronutrients for breastfeeding women for improving outcomes for the mother and baby

BACKGROUND

Globally, more than two billion people are estimated to be deficient in key vitamins and minerals, particularly iodine, iron and zinc. The majority of these people live in low-income settings and are typically deficient in more than one micronutrient. However, micronutrient deficiency among breastfeeding mothers and their infants also remains an issue in high-income settings, specifically among women who avoid meat and/or milk, women who may lack sufficient supplies of vitamin B12 and vitamin D, and/or women who are iron-deficient. Young children, pregnant and lactating women are particularly vulnerable to micronutrient deficiencies. They not only have a relatively greater need for vitamins and minerals because of their physiological state, but are also more susceptible to the harmful consequences of deficiencies. Multiple-micronutrient supplementation might be an option to solve these problems.

OBJECTIVES

The objective of this review was to evaluate the effects of multiple-micronutrient supplementation in breastfeeding mothers on maternal and infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials of multiple-micronutrient supplementation of three or more micronutrients versus placebo, no supplementation or supplementation with two or fewer micronutrients, irrespective of dosage of micronutrients, in breastfeeding mothers.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

We found no studies that compared multiple-micronutrient supplementation (with three or more micronutrients) versus supplementation with two or fewer micronutrients.Two small studies (involving a total of 52 women) were included. One study compared multiple micronutrients with placebo and the other study compared multiple micronutrients with a group who received no supplementation. The studies were carried out in Brazil (36 adolescent mothers) and the USA (16 women) and included women with a low socioeconomic status. A lack of information in the study reports meant that risk of bias could not be adequately assessed (unclear risk of bias for many domains). There were no quantitative data for any of this review's outcomes so meta-analysis was not possible.Neither of the studies reported on the primary outcomes of interest in this review: maternal morbidity (febrile illness, respiratory tract infection, diarrhoea), adverse effects of micronutrients within three days of receiving the supplement, infant mortality (defined as a child dying before completing the first year of age).One study reported qualitatively on maternal anaemia (a secondary outcome of this review) - the study found that multiple-micronutrient supplementation was effective for recuperating from anaemia but there were no data for inclusion in our analyses. Maternal satisfaction was not reported in the included studies. Similarly, none of this review's infant secondary outcomes were reported in the included studies: clinical micronutrient deficiency; morbidity episodes (febrile illness, respiratory tract infection, diarrhoea, other), adverse effects of micronutrients within three days of receiving the supplement.

AUTHORS' CONCLUSIONS

We found no evidence to quantitatively assess the effectiveness of multiple-micronutrient supplementation in improving health outcomes in mother and baby. The results of this review are limited by the small numbers of studies available, small sample sizes and the studies not reporting on the outcomes of interest in this review. There is no evidence to evaluate potential adverse effects of multiple-micronutrient supplements, particularly excess dosages.There is a need for high-quality studies to assess the effectiveness and safety of multiple-micronutrient supplementation for breastfeeding women for improving outcomes for the mother and her baby. Further research should focus on whether multiple-micronutrient supplementation during lactation compared with none, a placebo or supplementation with fewer than two micronutrients is beneficial to maternal and infant health outcomes. Future studies should collect data on outcomes beyond micronutrient concentrations, for example: maternal and infant morbidity, adverse effects, maternal satisfaction, the risks of excess supplementation, and potential adverse interactions between the micronutrients and the other outcomes. This would help to bridge the gap between research on intermediary outcomes and health outcomes in order to develop sound policy in this field. Future studies could more precisely assess a variety of multiple-micronutrient combinations and different dosages and look at how these affect maternal and infant health outcomes. Larger studies with longer follow-up would improve the quality of studies and provide stronger evidence. In most of the included studies, bias could not be adequately assessed due to lack of information, therefore attention should be given to adequate methods of randomisation and allocation concealment, adequate methods of blinding of the participants, providers and the outcome assessors to improve the methodological quality of studies in this field.

Hydrosoluble vitamins

The hydrosoluble vitamins are a group of organic substances that are required by humans in small amounts to prevent disorders of metabolism. Significant progress has been made in our understanding of the biochemical, physiologic and nutritional aspects of the water-soluble vitamins. Deficiency of these particular vitamins, most commonly due to inadequate nutrition, can result in disorders of the nervous system. Many of these disorders have been successfully prevented in developed countries; however, they are still common in developing countries. Of the hydrosoluble vitamins, the nervous system depends the most on vitamins B and C (ascorbic acid) for proper functioning. The B group vitamins include thiamin (vitamin B1), riboflavin (vitamin B2), niacin or niacinamide (vitamin B3), pantothenic acid (vitamin B5), pyridoxine or pyridoxal (vitamin B6) and cobalamin (vitamin B12). Clinical findings depend upon the deficiency of the underlying vitamin; generally, deficiency symptoms are seen from a combination rather than an isolated vitamin deficiency. True hereditary metabolic disorders and serious deficiency-associated diseases are rare and in general limited to particular geographic regions and high-risk groups. Their recognition is truly important as that determines the appropriate therapeutic management. The general availability of vitamins to practically everyone and several national health programs have saved many lives and prevented complications. However, there has been some apprehension for several decades about how harmless generous dosages of these vitamins are. Overt overdosages can cause vitamin toxicity affecting various body systems including the nervous system. Systemically, vitamin toxicity is associated with nonspecific symptoms, such as nausea, vomiting, diarrhea, and skin rash which are common with any acute or chronic vitamin overdose. At a national level, recommended daily allowances for vitamins become policy statements. Nutrition policy has far reaching implications in the food industry, in agriculture, and in food provision programs. Overall, water-soluble vitamins are complex molecular structures and even today, many areas of vitamin biochemistry still need to be explored. Many readers might be of the opinion that the classic forms of nutritional deficiency diseases have faded into the background of interesting history. This has caused their diverse symptoms to be neglected by most modern physicians since vitamin enrichment of many foods automatically erases them from their consideration in differential diagnosis. Vitamin B12 and folic acid deficiencies are discussed in other chapters.

The nutritional requirements of infants. Towards EU alignment of reference values: the EURRECA network

This paper presents a review of the current knowledge regarding the macro- and micronutrient requirements of infants and discusses issues related to these requirements during the first year of life. The paper also reviews the current reference values used in European countries and the methodological approaches used to derive them by a sample of seven European and international authoritative committees from which background scientific reports are available. Throughout the paper, the main issues contributing to disparities in micronutrient reference values for infants are highlighted. The identification of these issues in relation to the specific physiological aspects of infants is important for informing future initiatives aimed at providing standardized approaches to overcome variability of micronutrient reference values across Europe for this age group.

B vitamins in breast milk: relative importance of maternal status and intake, and effects on infant status and function

Infants should be exclusively breastfed for the first 6 mo of life. However, maternal deficiency of some micronutrients, conveniently classified as Group I micronutrients during lactation, can result in low concentrations in breast milk and subsequent infant deficiency preventable by improving maternal status. This article uses thiamin, riboflavin, vitamin B-6, vitamin B-12, and choline as examples and reviews the evidence for risk of inadequate intakes by infants in the first 6 mo of life. Folate, a Group II micronutrient, is included for comparison. Information is presented on forms and concentrations in human milk, analytical methods, the basis of current recommended intakes for infants and lactating women, and effects of maternal supplementation. From reports of maternal and/or infant deficiency, concentrations in milk were noted as well as any consequences for infant function. These milk values were used to estimate the percent of recommended daily intake that infants fed by a deficient mother could obtain from her milk. Estimates were 60% for thiamin, 53% for riboflavin, 80% for vitamin B-6, 16% for vitamin B-12, and 56% for choline. Lack of data limits the accuracy and generalizability of these conclusions, but the overall picture that emerges is consistent across nutrients and points to an urgent need to improve the information available on breast milk quality.

Riboflavin in development and cell fate

Riboflavin (7,8-dimethyl-10-ribitylisoalloxazine; vitamin B2) is a water-soluble vitamin, cofactor derivatives of which (FAD, FMN) act as electron acceptors in the oxidative metabolism of carbohydrate, amino acids and fatty acids and which in the reduced state can donate electrons to complex II of the electron transport chain. This means that riboflavin is essential for energy generation in the aerobic cell, through oxidative phosphorylation. The classic effects of riboflavin deficiency on growth and development have generally been explained in terms of these functions. However, research also suggests that riboflavin may have specific functions associated with cell fate determination, which would have implications for growth and development. In particular, riboflavin depletion interferes with the normal progression of the cell cycle, probably through effects on the expression of regulatory genes, exerted at both the transcriptional and proteomic level.

Vitamin requirements for term infants: considerations for infant formulae

OBJECTIVE

To provide the informed health professional with an up to date evaluation of the current thinking regarding requirements for vitamins in infant feeds. ESTABLISHING CRITERIA FOR ADEQUACY: Vitamin adequacy in the neonate is currently defined in terms of circulating levels of a vitamin or of the activity of a vitamin dependent enzyme in the erythrocytes. Although these measurements have their value there is a need to develop biochemical, physiological or clinical markers of well defined specific function. For some vitamins there is a risk of deleterious effects of very high intakes: risk of toxicity needs to be taken into consideration when making recommendations for inclusion in infant formulae. BREAST MILK AS THE 'GOLD STANDARD': Breast milk concentrations of vitamins have been used as the criteria of adequate intake by neonates. This may not always be justified. Greater consideration needs to be given to differences in bioavailability of vitamins from breast milk compared with formula feeds, of the influence of season, and of stage of lactation, on the stated composition.

EXPERIMENTAL APPROACHES

Animal studies have provided limited information regarding effects of different levels of intakes on current status indices in the neonatal period. There are few reports of randomized controlled studies into the effects of different levels of vitamins and these rely heavily on biochemical criteria of adequacy.

RECENT DEVELOPMENTS

The inclusion of beta-carotene into formula feeds for premature babies is an issue of current interest. What is the justification for this? Are there potential benefits for the term infant? Riboflavin deficiency in the period around weaning may affect the normal structural and functional development of the gastrointestinal tract; some of these effects may be permanent. RESEARCH TO BE DONE: A greater understanding of the absorption and metabolism of vitamins during infancy is required in order to help establish dietary requirements. The relative bioavailability of vitamins in human milk and formulae needs to be investigated. Criteria for vitamin adequacy should be extended to include measures of function. Information regarding the conversion factor from tryptophan to niacin in infancy would allow us to set niacin requirements with greater confidence. There is a particular lack of information about concentrations of biotin and pantothenic acid in breast milk and the relative biochemical status of infants receiving breast milk and formulae. Benefits of including beta-carotene into infant formulae need to be evaluated. The role of individual micronutrients in the structural and functional development of the gastrointestinal tract should be explored.

Low nutrient intakes among infants in rural Bangladesh are attributable to low intake and micronutrient density of complementary foods

We assessed the adequacy of nutrient intakes of 135 rural Bangladeshi breast-fed infants 6-12 mo of age and examined nutritional trade-offs due to possible displacement of breast milk by complementary foods. Observers completed 12-h daytime measurements of breast milk and complementary food intakes; data for the previous 12 h were obtained from maternal recall, yielding estimates of total 24-h intakes. On average, infants were mildly wasted (mean +/- SD weight-for-length Z-score = -0.92 +/- 0.88) and moderately stunted (length-for-age Z-score = -1.49 +/- 0.96). Total energy intakes at 6-8 and 9-12 mo were 88 and 86% of absolute energy requirements (kJ/d), 106 and 105% of requirements per kg body weight, and 97 and 94% of requirements per kg median weight-for-length, respectively. Breast milk contributed 78% of energy intake at 6-8 mo and 75% at 9-12 mo. Mean meal frequency and energy density of complementary foods were generally consistent with recommendations, but only small amounts of food were offered. Nevertheless, only 72% of the food energy offered was consumed. Total energy intake was positively correlated with meal frequency, quantity consumed per meal, and energy intake from breast milk, but not with energy density of complementary foods. Energy intake from complementary foods was inversely related to energy intake from breast milk. The diets fell short of recommended intakes for numerous vitamins and minerals. We conclude that although greater intakes of complementary foods were associated with higher total energy intake, micronutrient intake remained low due to the low micronutrient density of the complementary foods consumed and the partial displacement of breast milk.

B vitamins: proposed fortification levels for complementary foods for young children

The B vitamins, except for folate, can be classified as group I nutrients during lactation. Nutrients in this category share the following characteristics: low maternal intake or stores during lactation reduce the concentration in human milk, and infants' stores are readily depleted. For some of these nutrients, the infants' stores at birth may be depleted by maternal deficiency during pregnancy. The prevalence of some B vitamin deficiencies, especially deficiencies of riboflavin and vitamin B-12, is probably much higher than is usually assumed. Taken together, these considerations emphasize the importance of supplying adequate amounts of B vitamins to infants and young children. Recommendations are made here on the amounts and densities of B vitamins that should be present in fortified complementary foods fed to children aged 6-24 mo. The values are based on the difference between recommended daily intakes and the amount that the child will receive from maternal milk using estimates reported in the literature. There are few concerns about the potential toxicity of any of these vitamins at the levels likely to be added to complementary foods. If there are losses during food preparation or concentrations of the vitamins are low in human milk, the estimates provided may need to be increased. The adequacy of these recommendations must be evaluated thoroughly.

Riboflavin (vitamin B-2) and health

Riboflavin is unique among the water-soluble vitamins in that milk and dairy products make the greatest contribution to its intake in Western diets. Meat and fish are also good sources of riboflavin, and certain fruit and vegetables, especially dark-green vegetables, contain reasonably high concentrations. Biochemical signs of depletion arise within only a few days of dietary deprivation. Poor riboflavin status in Western countries seems to be of most concern for the elderly and adolescents, despite the diversity of riboflavin-rich foods available. However, discrepancies between dietary intake data and biochemical data suggest either that requirements are higher than hitherto thought or that biochemical thresholds for deficiency are inappropriate. This article reviews current evidence that diets low in riboflavin present specific health risks. There is reasonably good evidence that poor riboflavin status interferes with iron handling and contributes to the etiology of anemia when iron intakes are low. Various mechanisms for this have been proposed, including effects on the gastrointestinal tract that might compromise the handling of other nutrients. Riboflavin deficiency has been implicated as a risk factor for cancer, although this has not been satisfactorily established in humans. Current interest is focused on the role that riboflavin plays in determining circulating concentrations of homocysteine, a risk factor for cardiovascular disease. Other mechanisms have been proposed for a protective role of riboflavin in ischemia reperfusion injury; this requires further study. Riboflavin deficiency may exert some of its effects by reducing the metabolism of other B vitamins, notably folate and vitamin B-6.

Predictors of micronutrient status among six- to twelve-month-old breast-fed Ghanaian infants

This study describes the factors associated with hemoglobin and plasma ferritin, zinc and retinol concentrations and erythrocyte riboflavin status among 208 Ghanaian infants who participated in a complementary feeding intervention trial from 6 to 12 mo of age. Anthropometric, morbidity and dietary data were collected regularly from 1 to 12 mo; blood samples were collected at 6 and 12 mo. The prevalence of low micronutrient status at 6 and 12 mo, respectively, was as follows: hemoglobin <100 g/L, 30 and 34%; plasma ferritin <12 microg/L, 17 and 43%; plasma zinc <10.7 micromol/L, 4 and 6%; plasma retinol <0.7 micromol/L, 26 and 26%; erythrocyte riboflavin <200 umol/L of packed red cells, 14 and 10%. Multiple regression was used to identify factors significantly associated with micronutrient status. From 6 to 12 mo, fever prevalence was associated with a decrease in hemoglobin, but an increase in erythrocyte riboflavin concentrations, and diarrhea prevalence was related to a decrease in plasma retinol. Seasonal differences were evident for most of the indicators of micronutrient status, and elevated C-reactive protein levels (indicative of recent infection) were related to lower hemoglobin, retinol and zinc concentrations but higher ferritin and erythrocyte riboflavin concentrations. Weight at birth or at 1 mo of age was positively related to iron, zinc and vitamin A status, but a more rapid weight gain was associated with depletion of iron stores. Socioeconomic status was related to higher hemoglobin, riboflavin and zinc concentrations. The feeding of a micronutrient-fortified food was positively associated with plasma ferritin and retinol concentrations at 12 mo. These results suggest that prenatal factors, socioeconomic status, dietary intake and morbidity all influence infant micronutrient status, and that fortification of complementary foods is one potential avenue for preventing deficiencies.

A randomized, community-based trial of the effects of improved, centrally processed complementary foods on growth and micronutrient status of Ghanaian infants from 6 to 12 mo of age

BACKGROUND

Koko, a fermented maize porridge used as the primary complementary food in Ghana, has been implicated in the high prevalence of child malnutrition. Weanimix, a cereal-legume blend developed by the United Nations Children's Fund and the Ghanaian government, has been promoted as an alternative.

OBJECTIVE

We evaluated the effect of feeding Weanimix and 3 other locally formulated, centrally processed complementary foods on the nutritional status of 208 breast-fed infants.

DESIGN

Infants were randomly assigned to receive 1 of 4 foods from 6 to 12 mo of age: Weanimix (W), Weanimix plus vitamins and minerals (WM), Weanimix plus fish powder (WF), and koko plus fish powder (KF). Dietary and anthropometric data were collected regularly. Blood was collected at 6 and 12 mo of age to assess iron, zinc, vitamin A, and riboflavin status. Before and after the intervention, cross-sectional data on the anthropometric status of infants not included in the intervention (NI; n = 464) were collected.

RESULTS

There were no significant differences between intervention groups in weight or length gain or in hemoglobin, hematocrit, transferrin saturation, plasma zinc, or erythrocyte riboflavin values between 6 and 12 mo of age. From 9 to 12 mo of age, z scores were lower in NI infants than in the combined intervention groups [at 12 mo: -1.71 +/- 0.90 compared with -1.19 +/- 0.93 for weight and -1.27 +/- 1.02 compared with -0.63 +/- 0.84 for length (P < 0.001 for both), respectively]. The percentage of infants with low ferritin values increased significantly between 6 and 12 mo of age in groups W, WF, and KF but not in group WM. Change in plasma retinol between 6 and 12 mo of age was significantly greater in group WM than in the other 3 groups combined (0.14 +/- 0.3 compared with -0.04 +/- 0.3 micromol/L, P = 0. 003).

CONCLUSIONS

All 4 foods improved growth relative to the NI group. Infants fed WM had better iron stores and vitamin A status than those fed nonfortified foods.

Less diarrhoea but no change in growth: 15 years' data from three Gambian villages

AIMS

To review diarrhoea presentations and nutritional status in young rural Gambian children over a 15 year period as a test of an earlier hypothesis that reduced diarrhoea prevalence would lead to improved growth and a reduced prevalence of malnutrition.

SUBJECTS AND METHODS

Growth and morbidity were documented routinely in 1190 children under 2 years of age attending the Dunn Nutrition Group clinic at Keneba between 1979 and 1993.

RESULTS

The numbers of presentations with diarrhoea (1069 in 1979; 220 in 1993) and the proportion of clinic attendees with diarrhoea (30% in 1979; 8% in 1993) fell steadily between 1979 and 1993. However, at both 1 year old, mean weights (Z scores: 1979, -1.8; 1993, -1.8) and mean lengths (Z scores: 1979, -1.3; 1993, -1.7), and at 2 years old, mean weights (Z scores: 1979, -2.0; 1993, -1.9) and mean lengths (Z scores: 1979, -2.0; 1993, -2.1) did not change noticeably over the 15 year period.

CONCLUSION

Major progressive reductions in clinic presentations with diarrhoea have not been associated with improved nutritional status in this population of young rural Gambian children.

The epidemiology of clinical malaria among African children

There is a resurgence of interest in the clinical epidemiology of malaria among African children. This renewed interest follows fifty years of failure to eradicate infection in Africa and redirected efforts toward disease control and prevention. We have a poor understanding of the mechanisms by which clinical immunity is acquired; however, several recent studies have provided new insights into how fast clinical protection is acquired under the varied transmission intensities common to Africa. What is clear is that the frequency with which individuals encounter infection from birth will determine the speed with which they become clinically immune and the patterns of severe pathology they are likely to experience. There remains doubt and concerns over the long-term consequences of reducing natural parasite exposure in several areas of Africa. New field studies are urgently required to tackle these issues so that control may be guided by an improved understanding of malaria as a disease that can lead to death.

Riboflavin deficiency, metabolic rate and brown adipose tissue function in sucking and weanling rats

1. The effects of riboflavin deficiency on growth, whole-body oxygen consumption, cytochrome c oxidase (EC 1.9.3.1) activity and GDP-binding capacity of brown adipose tissue were measured in three groups of rats: sucking pups, weanling rats, and dams. Control groups were weight-matched, pair-fed or fed ad lib. 2. Riboflavin deficiency reduced growth rate and increased the activation coefficient of erythrocyte glutathione reductase (NAD(P)H) (EC 1.6.4.2), as predicted. In sucking pups it also reduced whole-body O2 consumption per unit body-weight, especially after noradrenaline stimulation. In weanling rats, however, it increased O2 consumption both before and after noradrenaline stimulation. 3. Cytochrome c oxidase (EC 1.9.9.1) activity of brown adipose tissue was not consistently affected by riboflavin deficiency. Binding of [3H]GDP to the mitochondria was increased in the deficient weanling rats. 4. Weanling rats therefore, seemed better able to withstand the effects of severe depletion. Their reduced growth and increased non-shivering thermogenesis helped to counteract the unfavourable ratio of riboflavin:other tissue-building materials. The relevance for thermoregulation in riboflavin-deficient children is discussed.

Glucose-6-phosphate dehydrogenase and glutathione reductase activity in methemoglobin reduction by methylene blue and cystamine. Study on glucose-6-phosphate dehydrogenase-deficient individuals, on normal subjects and on riboflavin-treated subjects

The authors have standardized methods for evaluation of the activity of the glucose-6-phosphate dehydrogenase and of glutathione reductase. The general principle of the first method was based on methemoglobin formation by sodium nitrite followed by stimulation of the glucose-6-phosphate dehydrogenase with methylene blue. Forty six adults (23 males and 23 females) were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. The results showed that methemoglobin reduction by methylene blue was 154.40 and 139.90 mg/min (p<0.05) for males and females, respectively, in whole blood, and 221.10 and 207.85 mg/min (n.s.), respectively, in washed red cells. These data showed that using washed red cells and 0.7g% sodium nitrite concentration produced no differences between sexes and also shortened reading time for the residual amount of methemoglobin to 90 minutes. Glutathione reductase activity was evaluated on the basis of the fact that cystamine (a thiol agent) binds to the SH groups of hemoglobin, forming complexes. These complexes are reversed by the action of glutathione reductase, with methemoglobin reduction occurring simultaneously with this reaction. Thirty two adults (16 males and 16 females) were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. Methemoglobin reduction by cystamine was 81.27 and 91.13 mg/min (p<0.01) for males and females, respectively. These data showed that using washed red cells and 0.1 M cystamine concentration permits a reading of the residual amount of methemoglobin at 180 minutes of incubation. Glutathione reductase activity was evaluated by methemoglobin reduction by cystamine in 14 females before and after treatment with 10 mg riboflavin per day for 8 days. The results were 73.69 and 94.26 jug/min (p<0.01) before and after treatment, showing that riboflavin treatment increase glutathione reductase activity even in normal individuals. Three Black G6PD-deficient individuals (2 males and 1 female) were also studied. The G6PD and glutathione reductase were partially activated, the change being more intense in males. On the basis of race and of the laboratory characteristics observed, it is possible to suggest that the G6PD deficiency of these individuals is of the African type and that the female is heterozygous for this deficiency. Analysis of the results as a whole permitted us to conclude that the methods proposed here were efficient for evaluating the activity of the glucose-6-phosphate dehydrogenase and of glutathione reductase. The latter is dependent on the pentose pathway, which generates NADPH, and on riboflavin, a FAD precursor vitamin.

Effect of leucine on intestinal absorption of tryptophan in rats

1. To elucidate the causal relation between leucine and the lowering of hepatic NAD content of rats fed on a leucine-excessive diet (Yamada et al. 1979), the effect of leucine on intestinal absorption of tryptophan was investigated. 2. Co-administration of [3H]tryptophan and leucine, with leucine at ten times the level of tryptophan, delayed absorption of L-[side chain 2,3-3H]tryptophan from the digestive tract and incorporation of [3H]tryptophan into portal blood, the liver and a protein fraction of the liver. After 120 min, more than 95% of tryptophan was absorbed whether [3H]tryptophan was administered with or without leucine. 3. Co-administration of a mixture of ten essential amino acids, in proportions simulating casein, with [3H]tryptophan markedly delayed absorption of tryptophan from the digestive tract. The addition of supplementary leucine to the amino acid mixture, however, caused no further delay. 4. In rats prefed a leucine-excessive diet for 1 week [3H]tryptophan was absorbed at the same rate as in rats fed on a control diet. 5. The results indicate that competition between tryptophan and leucine for intestinal absorption did not cause lowering of hepatic NAD.

Normal vitamin requirements in neonates and infants

Information about vitamin requirements by neonates and infants has been derived from studies of the composition of breast milk, from feed-response trials, from the occurrence of overt deficiency in infants fed damaged milk formulae, and by extrapolation from experimental deficiency studies on adult humans and on animals. Our knowledge is far from complete, however, and dietary recommendations have been formulated for only about half the known vitamins in the UK. In the near future, studies with stable isotope-labelled vitamins should help to define pool sizes and turnover rates that are associated with particular intakes and thus give firmer evidence about requirements.

Effect of riboflavin deficiency on lipid metabolism of liver and brown adipose tissue of sucking rat pups

An increase in liver: body-weight and in hepatic triacylglycerol content, together with changes in the fatty acid profiles of hepatic phospholipids, were observed as a result of moderate riboflavin deficiency in sucking rat pups. Oxygen consumption by hepatic mitochondria, with palmitoyl L-carnitine as substrate, was not significantly impaired. Mitochondria from interscapular brown adipose tissue, however, showed a marked impairment of O2 consumption, with palmitoyl L-carnitine as substrate, in the riboflavin-deficient pups. This impairment was also apparent after uncoupling with carbonyl cyanide p-trifluoromethoxyphenylhydrazone, but was not consistently observed after the addition of GDP to suppress uncoupled oxidation. It was much less evident, and did not reach statistical significance, for the mitochondria of brown adipose tissue of the corresponding deficient dams. Binding of 3H-labelled GDP by brown adipose tissue mitochondria was unaffected by riboflavin deficiency in the pups, suggesting that the effect on O2 consumption is more likely to be due to impaired integrity of the mitochondrial respiratory chain, than to impairment of the specific capacity for uncoupling of respiration which is characteristic of brown adipose tissue mitochondria. Total cytochrome c oxidase (EC 1.9.3.1) activity of the brown adipose tissue of riboflavin-deficient pups was not significantly reduced. A small but significant impairment was observed in the stimulation of whole-body O2 consumption by injected noradrenaline in the riboflavin-deficient pups, suggesting that the impairment of brown adipose tissue mitochondrial function may be accompanied by impaired physiological capacity in vivo.

Effect of riboflavin deficiency on reproductive performance and on biochemical indices of riboflavin status in the rat

Young female rats were made riboflavin-deficient by feeding a purified diet containing casein (210 g/kg). This basal diet provided 0.40 mg riboflavin/kg diet, to which was added additional riboflavin at 0, 0.12 or 0.25 mg/kg diet. Control animals received the same diet with 15 mg added riboflavin/kg. The diets were given for 4 weeks before mating, then throughout pregnancy and for 15 d of lactation. With no added riboflavin in the diet, reproduction was severely impaired and fetal resorption was usually observed. With 0.12 mg added riboflavin/kg diet, however, reproduction was usually successful, and the growth of dams and pups was only marginally depressed in comparison with pair-fed controls optimally supplied with riboflavin. The activation coefficient (stimulated:basal activity) of erythrocyte glutathione reductase (NAD(P)H) (EC 1.6.4.2) was high, and the concentration of riboflavin in the liver was correspondingly low in the dams receiving diets containing 0.12 or 0.25 mg added riboflavin/kg and in their sucking pups at 15 d post partum. Riboflavin levels in the milk from both groups of dams were about eightfold lower than in controls. There was little evidence that the sucking pups could maintain their riboflavin level at the expense of that in the maternal tissues.

Transient riboflavin depletion in preterm infants

Biochemical riboflavin status was measured in 68 preterm infants who were receiving either human milk or a preterm infant formula (containing riboflavin, 1.8 mg/l) during the first few weeks of life. The relation between riboflavin status, type of diet, and time of introduction of a multivitamin supplement containing riboflavin was analysed and the duration of phototherapy was recorded. Those who received the multivitamin supplement on or before day 7 of life seldom became deficient and no significant difference between diets was seen in this group. Of those who received the supplement after day 7, human milk fed infants commonly developed abnormal riboflavin status (18 out of 23 infants) compared with a small and significantly lower incidence in the formula fed group. Dietary effects on riboflavin status seemed to outweigh in importance those of phototherapy. It is concluded that the riboflavin content of human milk, which may be lowered by photodegradation, is not sufficient to ensure normal biochemical status in preterm infants. The larger amounts provided by a multivitamin supplement or by a preterm infant formula may, however, prevent biochemical deficiency. The desirability (and safety) of routine riboflavin supplementation of preterm infants is discussed.