Excess filaggrin in keratinocytes is removed by extracellular vesicles to prevent premature death and this mechanism can be hijacked by Staphylococcus aureus in a TLR2-dependent fashion

Filaggrin (FLG) protein is indispensable for multiple aspects of the epidermal barrier function but its accumulation in a monomeric filaggrin form may initiate premature keratinocytes death; it is unclear how filaggrin levels are controlled before the formation of storing keratohyalin granules. Here we show that keratinocyte-secreted small extracellular vesicles (sEVs) may contain filaggrin-related cargo providing a route of eliminating excess filaggrin from keratinocytes; blocking of sEV release has cytotoxic effects on those cells. Filaggrin-containing sEVs are found in plasma in both healthy individuals and atopic dermatitis patients. Staphylococcus aureus (S. aureus) enhances packaging and secretion of filaggrin-relevant products within the sEVs for enhanced export via a TLR2-mediated mechanism which is also linked to the ubiquitination process. This filaggrin removal system, preventing premature keratinocyte death and epidermal barrier dysfunction, is exploited by S. aureus which promotes filaggrin elimination from the skin that could help safeguard bacterial growth.

In silico analysis of the profilaggrin sequence indicates alterations in the stability, degradation route, and intracellular protein fate in filaggrin null mutation carriers

Background: Loss of function mutation in FLG is the major genetic risk factor for atopic dermatitis (AD) and other allergic manifestations. Presently, little is known about the cellular turnover and stability of profilaggrin, the protein encoded by FLG. Since ubiquitination directly regulates the cellular fate of numerous proteins, their degradation and trafficking, this process could influence the concentration of filaggrin in the skin. Objective: To determine the elements mediating the interaction of profilaggrin with the ubiquitin-proteasome system (i.e., degron motifs and ubiquitination sites), the features responsible for its stability, and the effect of nonsense and frameshift mutations on profilaggrin turnover. Methods: The effect of inhibition of proteasome and deubiquitinases on the level and modifications of profilaggrin and processed products was assessed by immunoblotting. Wild-type profilaggrin sequence and its mutated variants were analysed in silico using the DEGRONOPEDIA and Clustal Omega tool. Results: Inhibition of proteasome and deubiquitinases stabilizes profilaggrin and its high molecular weight of presumably ubiquitinated derivatives. In silico analysis of the sequence determined that profilaggrin contains 18 known degron motifs as well as multiple canonical and non-canonical ubiquitination-prone residues. FLG mutations generate products with increased stability scores, altered usage of the ubiquitination marks, and the frequent appearance of novel degrons, including those promoting C-terminus-mediated degradation routes. Conclusion: The proteasome is involved in the turnover of profilaggrin, which contains multiple degrons and ubiquitination-prone residues. FLG mutations alter those key elements, affecting the degradation routes and the mutated products' stability.

Exposure of Keratinocytes to Candida Albicans in the Context of Atopic Milieu Induces Changes in the Surface Glycosylation Pattern of Small Extracellular Vesicles to Enhance Their Propensity to Interact With Inhibitory Siglec Receptors

Candida albicans (C. albicans) infection is a potential complication in the individuals with atopic dermatitis (AD) and can affect clinical course of the disease. Here, using primary keratinocytes we determined that atopic milieu promotes changes in the interaction of small extracellular vesicles (sEVs) with dendritic cells and that this is further enhanced by the presence of C. albicans. sEV uptake is largely dependent on the expression of glycans on their surface; modelling of the protein interactions indicated that recognition of this pathogen through C. albicans-relevant pattern recognition receptors (PRRs) is linked to several glycosylation enzymes which may in turn affect the expression of sEV glycans. Here, significant changes in the surface glycosylation pattern, as determined by lectin array, could be observed in sEVs upon a combined exposure of keratinocytes to AD cytokines and C. albicans. This included enhanced expression of multiple types of glycans, for which several dendritic cell receptors could be proposed as binding partners. Blocking experiments showed predominant involvement of the inhibitory Siglec-7 and -9 receptors in the sEV-cell interaction and the engagement of sialic acid-containing carbohydrate moieties on the surface of sEVs. This pointed on ST6 β-Galactoside α-2,6-Sialyltransferase 1 (ST6GAL1) and Core 1 β,3-Galactosyltransferase 1 (C1GALT1) as potential enzymes involved in the process of remodelling of the sEV surface glycans upon C. albicans exposure. Our results suggest that, in combination with atopic dermatitis milieu, C. albicans promotes alterations in the glycosylation pattern of keratinocyte-derived sEVs to interact with inhibitory Siglecs on antigen presenting cells. Hence, a strategy aiming at this pathway to enhance antifungal responses and restrict pathogen spread could offer novel therapeutic options for skin candidiasis in AD.

The impact of inter-generational social and regional circumstances on dietary intake patterns of British adults: results from the 1946 British Birth Cohort

Objectives:

(1) To determine the extent to which an individual's childhood social circumstances and region of residence influence their dietary pattern at age 43 years and (2) to establish the extent to which an individual adopts the dietary pattern of their social and regional circumstances at age 43 years.

Design:

Longitudinal study of a social class stratified, random sample of all legitimate, singleton births in the week of 3–9 March 1946.

Settings:

England, Scotland and Wales.

Subjects:

The 3187 survey members who provided sociodemographic information at age 4 years in 1950 and sociodemographic and dietary data (48-hour dietary recall) at 43 years in 1989.

Results:

People who remained in the non-manual social class consumed significantly higher amounts of food items correlated with the factor health aware (items include high-fibre breakfast cereals, wholemeal breads, apples and bananas) than those who remained in the manual social class. Those who made the transition from manual social class in childhood to non-manual social class at age 43 years partly adopted the distinctive dietary patterns of the non-manual social classes. Consumption of items in the factors refined (items include whole-fat milk, white bread, sugar and butter) and sandwich (items include tomatoes, lettuce, onions, bacon and ham) did not differ by social class or regional mobility.

Conclusions:

This work suggests that although adult dietary patterns are developed as a result of childhood influences, these patterns can be modified as a result of social and regional transitions. Such changes in dietary patterns may influence susceptibility to disease.

Changes in intake of key nutrients over 17 years during adult life of a British birth cohort

An investigation was carried out to determine whether there were significant changes in nutrient intake over 17 years of adult life. The Medical Research Council National Survey of Health and Development is a longitudinal study of a nationally representative cohort of singleton births in the UK in 1946. Of this cohort, 1253 survey members provided information on diet recorded in a 5 d diary at age 36 years in 1982, 43 years in 1989 and 53 years in 1999. The outcome measures were mean intakes of energy, macronutrients, minerals and vitamins. There were significant changes in the intake of most nutrients in 1999 compared with previous years. Intakes of fat, Na, Fe and Cu have fallen, but there was a rising trend in the intakes of Ca, P, carotene, thiamin, pyridoxine, folic acid and vitamins C, D and E in both men and women. Additionally, intakes of K, Mg and vitamin K1 have risen in women. There were significant gender differences, women showing a higher percentage rise in the intakes of carotene, riboflavin, folic acid, vitamin C and vitamin E. These changes were related to changes in the consumption of certain key foods, such as the increased consumption of fruit and vegetables and a shift away from whole milk, butter and red meat. Most of these trends are in line with accepted nutritional guidelines. How far these changes are due to consumer choice and real changes in food composition or are due to artefacts inherent in the methodology is discussed.

Comparability of dietary patterns assessed by multiple dietary assessment methods: results from the 1946 British Birth Cohort

OBJECTIVE

The aim of this study is to evaluate the consistency of dietary patterns assessed through the use of a dietary recall and a 5-day food diary.

DESIGN

Participants (n = 2265) of a longitudinal study of health and development completed 48-h dietary recall at interview, followed by a 5-day food diary and with the 24 h immediately preceding the interview analysed separately as a 24-h recall. Mean intakes of foods and nutrients were calculated and dietary patterns were assessed using exploratory factor analysis, using the method of principal components. Paired t-tests and correlation coefficients were used to compare the three dietary assessment methods.

RESULTS

Five distinct dietary patterns were identified using the food diary and the 48-h recall but were less consistent on the 24-h recall. Correlations between factor scores on the 48-h recall and the food diary (r = 0.13-0.67) were higher than those between the 24-h recall and food diary (r = -0.01-0.59). The recall methods were effective at ranking subjects according to food and nutrient intakes, with the 48-h recall and food diary showing higher correlations in both males and females.

CONCLUSIONS

This study indicates that a 48-h recall effectively characterises dietary patterns in British adults when compared to a food diary and ranks participants appropriately with respect to most nutrients and foods and is superior to a single 24-h recall. These results have implications for longitudinal studies where maximising response rates to repeat dietary assessment tools is essential.

Dietary acid-base balance and intake of bone-related nutrients in Cambridge teenagers

OBJECTIVES

To evaluate the diet of 16-18-y-old boys and girls with particular reference to intakes of nutrients believed to affect bone health and dietary acid-base balance.

DESIGN

A 7-day food diary was completed between the months of October and December.

SETTING

Cambridge, UK.

SUBJECTS

A total of 111 boys and 101 girls aged 16-18 y who were recruited into the Cambridge Bone Studies.

MAIN OUTCOME MEASURES

Mean daily intakes of foods and selected nutrients (protein, calcium, phosphorus, magnesium, potassium, vitamins C and K) were calculated. Two estimates of acid-base balance were calculated from the diet using the formulae of Remer (net acid excretion, estimated indirectly; NAE(ind)) and Frassetto (protein/potassium ratio).

RESULTS

Mean calcium and phosphorus intakes were above the UK Reference Nutrient intake (RNI). In all, 39% of the boys and 36% of the girls had vitamin K intakes lower than 1 microg/kg body weight/day. Calcium intake was positively correlated with all other nutrients except vitamins C and K. Boys had a significantly higher estimated net acid excretion (NAE(ind)) than girls (P<0.001). Although a strong correlation (r=0.76, P<0.001) was found between the two methods, at higher acid levels a divergence was observed. A significant positive correlation was found between NAE(ind) and the weight consumed per day of milk, cheese, meat and cereal foods and a negative correlation was found with the weight of potatoes and fruit. Diet composition is such that a lower NAE(ind) is accompanied by a lower calcium intake.

CONCLUSIONS

The interpretation of the effects of calcium and other nutrients on bone cannot be considered in isolation from the other components of the diet. These results challenge some of the accepted perceptions about what constitutes an optimal diet for the promotion of bone health in adolescents.

Childhood and adult dietary vitamin E intake and cardiovascular risk factors in mid-life in the 1946 British Birth Cohort

OBJECTIVES

To determine whether dietary vitamin E intake in childhood or mid-life was predictive of adult hypertension and high waist circumference, as two important risk factors for cardiovascular disease.

DESIGN

Longitudinal study of a social class stratified random sample of all the legitimate, singleton births in the week of 3-9 March 1946.

SETTINGS

England, Scotland and Wales.

SUBJECTS

The 2980 survey members who provided information on diet, health and sociodemographic information at two time points; age 4 y in 1950 (24-h dietary recall) and 43 y in 1989 (48-h dietary recall).

MAIN OUTCOME MEASURES

Outcomes were adjusted odds ratios (ORs) for hypertension and high waist circumference at age 43 y by thirds of vitamin E intake, relative to the highest intake thirds at both ages.

RESULTS

The lowest consumers of vitamin E in both childhood and adulthood were more likely to be hypertensive (OR 1.8, 95% confidence interval (CI): 1.03-3.08) and have high waist circumference (OR 1.6, 95% CI: 1.02-2.43) than those consuming high levels at both ages. A low intake of vitamin E at just one time point was not associated with a statistically significant increased risk of hypertension or high waist circumference. Social class was also an independent and equally strong predictor of these coronary risk factors, indicating that the relation between social class and cardiovascular risks was not mediated solely by the current measures of diet and lifestyle.

CONCLUSIONS

Unique data on vitamin E intake from foods in both childhood and adulthood have indicated that relatively low intake of vitamin E at both ages predicted hypertension and high waist circumference at age 43 y.

Weight reference charts for British long-term breastfed infants

AIM

To produce a modification of the British 1990 weight reference reflecting the growth of long-term breastfed infants.

METHODS

120 infants from the Cambridge Infant Growth Study fed breast milk (with no formula) for at least 24 wk, with solids introduced at a mean age of 15 wk, were weighed every 4 wk from birth to 52 wk. Weights were converted to standard deviation scores (SDS) for gender and age post-term based on the revised British 1990 reference, averaged and smoothed across age, and then converted back to weights to provide modified median weight curves by gender. Other centile curves were constructed assuming the same variability and skewness by age as for the British reference.

RESULTS

Long-term breastfed infants were slightly heavier than the reference at birth and crossed centiles upwards to reach +0.3 SDS at 2 mo, but subsequently crossed centiles downwards to -0.2 SDS by 12 mo.

CONCLUSION

The British 1990 reference, although better than previous growth standards, reflects the growth of long-term breastfed infants only imperfectly, with mean weight falling by 0.5 SDS from 2 to 12 mo. The provision of breastfeeding-specific centiles, either as a transparent overlay or as an alternative chart, should be useful for professionals and parents to monitor the weight of long-term breastfed infants.

Sociodemographic inequalities in the diet of young children in the 1946 British birth cohort

OBJECTIVE

To evaluate whether there was food and nutrient equality across occupational social classes and geographical region for members of the 1946 British birth cohort at age 4 years.

DESIGN

Cross-sectional analysis of selected food groups, energy and nutrients from one-day recall diet records.

SETTING

England, Scotland and Wales in 1950.

SUBJECTS

Nationally representative sample of 4419 children aged 4 years in 1950 from the MRC National Survey of Health and Development (NSHD) (1946 Birth Cohort).

RESULTS

Significant food and nutrient inequalities occurred by region and occupational social class of the father. Disparity in fruit and vegetable consumption primarily led to the nutrient differences, especially with respect to lower vitamin C and carotene intakes in children from Scotland and from a manual social class background. Lower energy intake in Scottish children was attributable to inequality in the consumption of foods providing fat, and also to the retention of the traditional Scottish diet that included porridge and soups. Consumption of some rationed foods -- bacon, orange juice and tea -- was inequitably distributed by father's social class, but others, in particular meat and spreading fats, were consumed more uniformly. In contrast to fruits and vegetables, which showed marked sociodemographic disparities, other non-rationed foods such as bread and potatoes were consumed universally.

CONCLUSION

Local cultural norms may have played as strong a part in sociodemographic differences in the diet of children in the early 1950s as did the strict, post-war food rationing that prevailed. In consequence, nutritional equality was not achieved, and the relatively low intake of antioxidant vitamins during early childhood in certain population groups may have compromised health in the long term.

Intake and sources of phylloquinone (vitamin K1): variation with socio-demographic and lifestyle factors in a national sample of British elderly people

Intake and sources of phylloquinone (vitamin K1) were examined according to socio-demographic and lifestyle factors in free-living British people aged 65 years and over, from the 1994-5 National Diet and Nutrition Survey. Complete 4-d weighed dietary records were obtained from 1152 participants living in private households. Using newly-available, mainly UK-specific food content data, the weighted geometric mean intake of phylloquinone was estimated at 65 (95 % CI 62, 67) microg/d for all participants, with higher intakes in men than in women (70 v. 61 microg/d respectively, P<0.01). The mean nutrient densities of phylloquinone intake were 9.3 and 10.5 microg/MJ for men and women respectively (P<0.01), after adjusting for age group, region and smoking status. Of all the participants, 59 % had phylloquinone intakes below the current guideline for adequacy of 1 microg/kg body weight per d. Participants aged 85 years and over, formerly in manual occupations, or living in Scotland or in northern England reported lower phylloquinone intakes than their comparative groups. Overall, vegetables contributed 60 % of total phylloquinone intake, with cooked green vegetables providing around 28 % of the total. Dietary supplements contributed less than 0.5 % of phylloquinone intake. Participants living in northern England or in Scotland, in particular, derived less phylloquinone from vegetables than those living in southern England.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in a national sample of British elderly people

Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994-5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0.36 (inner 95% range [corrected] 0.06, 2.01) and 0.24 (inner 94% range [corrected] 0.06, 0.96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r 0.18 and 0.30 respectively, both P<0.001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, alpha- and gamma-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.

Leg and trunk length at 43 years in relation to childhood health, diet and family circumstances; evidence from the 1946 national birth cohort

BACKGROUND

This is a study of the associations of adult leg and trunk length with early life height and weight, diet, socioeconomic circumstances, and health, and parental height, divorce and death.

METHOD

The data used were collected in a longitudinal study of the health, development and ageing of a British national birth cohort (N = 2879 in this analysis) studied since birth in 1946. Multiple regression models were used to investigate the relationships.

RESULTS

Adult leg and trunk length were each positively associated with parental height, birthweight, and weight at 4 years. Leg length was associated positively with breastfeeding and energy intake at 4 years. Trunk length was associated negatively with serious illness in childhood and possibly also parental divorce, but not with the dietary data.

CONCLUSION

Adult leg length is particularly sensitive to environmental factors and diet in early childhood because that is the period of most rapid leg growth. Trunk growth is faster than leg growth after infancy and before puberty, and may be associated with the effects of serious illness and parental separation because of the child's growing sensitivity to stressful circumstances, as well as the result of the biological effects of illness.

Effects of the class III antiarrhythmic agent dofetilide (UK-68,798) on L-type calcium current from rabbit ventricular myocytes

The methanesulphonanilide agent dofetilide (UK-68,798) exerts Class III antiarrhythmic effects by inhibiting the cardiac rapid delayed rectifier potassium current (I(Kr)) encoded by HERG. The aim of the present study was to determine whether dofetilide also exhibits Class IV (L-type calcium-channel blocking) effects. L-type calcium current (I(Ca,L)) was measured from rabbit isolated ventricular myocytes, using the whole-cell patch-clamp technique under selective recording conditions. Positive control experiments demonstrated inhibition of I(Ca,L) elicited by pulses to + 10 mV by both nifedipine and externally applied Ni2+ ions. Three concentrations of dofetilide were tested: 100 nM, 1 microM and 10 microM. I(Ca,L) magnitude was not significantly reduced by any of the concentrations tested (P > 0.05; n = minimum of seven cells per drug concentration). The inactivation time-course of I(Ca,L) was also unaffected by 10 microM dofetilide. Heterologously expressed HERG current (I(HERG)) recorded from Chinese Hamster Ovary cells was extensively inhibited by 100 nm and 1 microM dofetilide, with inhibition at 1 microM not significantly different from 100% (P > 0.1). It is concluded that dofetilide produced no I(Ca,L) blocking effects at concentrations up to and exceeding that required for maximal I(HERG) inhibition. The findings support the notion that dofetilide is a highly selective Class III antiarrhythmic agent, devoid of Class IV antiarrhythmic activity.

Inhibition of HERG potassium channel current by the class 1a antiarrhythmic agent disopyramide

The Class 1a antiarrhythmic drug disopyramide (DISO) is associated with 'acquired' prolongation of the QT interval of the electrocardiogram (ECG). This potentially proarrhythmic effect is likely to reflect drug actions on ion channels involved in ventricular action potential repolarisation. In this study, we examined the effects of DISO on potassium channels encoded by HERG, as this K channel type has been implicated in both congenital and acquired long-QT syndromes (LQTS). Chinese hamster ovary cells were transiently transfected with HERG cDNA for subsequent whole cell patch clamp recording. HERG tail currents recorded at -40 mV following test pulses to +30 mV were inhibited in a dose-dependent fashion by DISO concentrations within the clinical range (IC50 = 7.23 +/- 0.72 microM; mean +/- SEM). Experiments with 10 microM DISO indicated that the degree of HERG blockade showed some voltage dependence. Further data obtained using an 'envelope of tails' protocol (pulse potential +40 mV) were consistent with a significant role for open-channel blockade at lower drug concentrations. At higher concentrations it is possible that blockade may have involved drug binding to both resting and open channels. Inhibition of the inactivation-deficient mutant HERG-S631A was comparable to that seen for wild-type HERG. Therefore, channel inactivation was not obligatory for DISO to exert its effect. Native delayed rectifier tail currents from rabbit isolated ventricular myocytes were also inhibited by DISO. We conclude (a) that DISO inhibits HERG encoded potassium channels at clinically relevant concentrations and (b) that this action may constitute the molecular basis for acquired LQTS associated with this drug.

Fat and energy needs of children in developing countries

The fat requirements of children can be judged according to 4 criteria: 1) the possible obligate needs of fat as a metabolic fuel, 2) the provision of a sufficiently energy-dense diet to meet energy needs, 3) the adequate supply of essential fatty acids, and 4) the supply of sufficient fat to allow adequate absorption of fat-soluble vitamins. In these respects the fat requirements of children in developing countries are probably similar to those of children in affluent nations except for the additional needs imposed by environmental stresses, particularly recurrent infections. In many developing countries, the low energy density of weaning foods appears to be a major contributor to growth faltering and ultimate malnutrition. Evidence from doubly labeled water studies suggests that these diets are adequate when children are healthy but fail to support rapid catch-up growth after diarrhea and other infections. The issues in determining and meeting the fat needs of children in developing countries are illustrated with use of detailed comparative dietary data from a rural community in The Gambia and from Cambridge, United Kingdom. The outstanding feature of the Gambian data is the great importance of breast milk as a source of fat and essential fatty acids up until the end of the second year of life. Weaning foods and adult foods contain low amounts of fat, which causes a sharp transition from adequate fat intakes to probable inadequate fat intakes when children are weaned from the breast. The effects of such low fat intakes, particularly in terms of immune function, require investigation.

Long-term adequacy of exclusive breast-feeding: how scientific research has led to revised opinions

The present paper reviews the research of the authors and their colleagues over the past 20 years to provide improved nutritional and anthropometric guidelines for the assessment of lactational adequacy and for when the weaning process might be initiated. The nutritional guidelines are based on revised dietary energy requirements. The basic assumption is that since breast milk is a well-balanced food, if energy needs are satisfied so will those for essential nutrients. Energy requirements for young babies have been derived from the application of the doubly-labelled-water technique. This approach indicated that 460 kJ (110 kcal)/kg per d at 1 month and 397 and 355 kJ (95 and 85 kcal)/kg per d at 3 and 6 months respectively would be satisfactory for a nutrient content of high bioavailability. Translated into a breast-milk intake of 850 ml/d the latter would cover the dietary energy needs of the average child growing along the 50th centile until at least 4 months, but the typical child from many developing countries following the 25th centile until 6 months. The importance of revised growth reference values for infancy, equally crucial for assessing lactational adequacy, is also reviewed. In contrast with the shapes of earlier reference patterns, growth trajectories are different when babies are fed in accordance with modern paediatric advice. Mothers and health professionals using the older growth charts to assess the progress of a baby can be misled into assuming that the weaning process needs to be introduced sooner than necessary. Examples of this situation within the context of a developing country are provided.

Food and nutrient intake of a national sample of 4-year-old children in 1950: comparison with the 1990s

OBJECTIVE

To evaluate the food and nutrient intake of members of a birth cohort study when young children in 1950 and investigate differences from present-day children's diets.

DESIGN

One-day recall diet records from the MRC National Survey of Health and Development (NSHD) (1946 Birth Cohort) at age 4 years were analysed for energy and selected nutrients and compared to the published results for 4-year-olds in the 1992/93 National Diet and Nutrition Survey (NDNS).

SETTING

England, Scotland and Wales in 1950 and 1992/93.

SUBJECTS

4,599 children in 1950 and 493 children in 1992/93.

RESULTS

Mean (SD) daily intakes in 1950 were energy 1,445 (343) kcal, or 6.1 (1.4) MJ, protein 46 (11)g, fat 64 (20)g, starch 117 (33)g, sugar 62 (24)g, unavailable carbohydrate 13 (4)g, calcium 736 (230) mg, iron 7.7 (2.1) mg, retinol 738 (1,273) microg, carotene 1,049 (1,130) microg and vitamin C 40 (26) mg. Compared to 1992/93, the 1950 diet contained substantially more bread and vegetables and less sugar and soft drinks, giving it a higher starch and fibre content and making it more in line with current recommendations on healthy eating. However, fat provided 40% of energy in 1950, compared to 35% in 1992/93. In 1950, red meat was an important source of iron, but by 1992 most iron came from fortified breakfast cereals. Vitamin C came mainly from vegetables in 1950, but from soft drinks in 1992.

CONCLUSIONS

The relative austerity of post-war food supplies resulted in food and nutrient intakes in 1950 which in many respects may well have been beneficial to the health of young children, despite fat intake being higher than present-day recommendations.

The need for revised standards for skinfold thickness in infancy

Skinfold standards provide a useful indication of subcutaneous fat. To evaluate skinfold thickness of 252 Cambridge infants over the first 2 years of age, SD scores relative to the Tanner standards were calculated, taking account of skewness in the standards. Cambridge SD scores were low, varying according to age from -1.2 to -1.8 for triceps and -0.6 to -1.2 for subscapular skinfolds. The Tanner skinfold standards were last revised 30 years ago, at a time of high prevalence of infantile obesity, and the present and other studies indicate that infants are now thinner. There is a need for new skinfold standards to reflect this change. Since the Cambridge infants contributed to the recent British height and weight references, it is suggested that their skinfold measurements could also serve as reference points.

Zinc and phytate intake of rural Gambian infants: contributions from breastmilk and weaning foods

Zinc and phytate intakes of 183 rural Gambian infants were obtained from weighed records of breastmilk and food intake and measured contents in foods. Total zinc intake of 2.7 mg/d in the first month of age declined to 1.5 mg/d at 3 months, then increased to 4.3 mg/d by 17 months. Breastmilk was an important source of zinc, but the predominant cereal and groundnut-based foods had high [phytate]/[Zn] molar ratios ranging from 13 to 28, indicating potential impaired zinc bioavailability. The [phytate]/[Zn] molar ratio for the diet as a whole was low in early infancy, but increased to 13 in the second year. In contrast, this ratio was less than 6 for the diet of 48 Cambridge breastfed infants up to 18 months. A further disadvantage to the Gambian infants was indicated by their lower intake of protein of animal origin. However, calcium intake was estimated in both communities to be below the level which could give rise to zinc chelation in association with phytate. Compared to 'basal' and 'normative' requirements, total zinc intake of the Gambian infants showed the greatest shortfall between 3 and 12 months, making this the age band for maximum probable benefit from focused intervention programmes.

Characteristics of the low-energy reporters in a longitudinal national dietary survey

The aim of the present study was to establish whether the characteristics of members of a large national birth cohort study who submitted diet diaries with implausibly low-energy intake differed from those whose recorded energy intake was more plausible. Survey members (n 1898) recorded their diets in a 7 d diary in household measures. Those whose reported energy intake (EI) as a fraction of their estimated BMR was less than 1.10, here termed low-energy reporters (LER) but often called under-reporters, constituted 20.6% of the study population. None of the variables describing dietary, smoking or exercise behaviour bore a significant relationship with low EI/BMR (< 1.10), neither did those describing region of residence, subjective adequacy of income, current social class, social relations or the social environment of the subjects. Results of logistic regression analysis showed that the only independently significant characteristic for men was higher BMI. In women, in addition to higher BMI, having been overweight or obese as an adult independently, but less significantly, predicted low EI/BMR, while membership as a child of social class III (non-manual), having more children in the household and having a paid job marginally but independently decreased the probability of reporting low EI/BMR. Submission of a diary with EI/BMR < 1.10 7 years earlier in the same survey was an even more powerful predictor of current low EI/BMR than higher BMI in both sexes. The average reported diet-composition of LER was more micronutrient- and protein-rich than that of the others, indicating different dietary, or diet-recording, behaviour in this group of subjects. LER are not a random sample of the survey population, and their characteristics, definable to some extent, put them at risk for lower health status. Although EI/BMR cut-off points can be used to identify LER, the problem of how to use their data is still unresolved.

Seasonal variations in vitamins A, C, riboflavin and folate intakes and status of pregnant and lactating women in a rural Gambian community: some possible implications

OBJECTIVE

To relate measured intake of vitamins A, C, folate and riboflavin to biochemical indicators of nutritional status for these micronutrients, and to examine seasonal variations.

SETTING

MRC Dunn Nutrition Unit Field Station, Keneba, The Gambia, which has heavy rainfall in August, and little or no rain between late September and mid-June. Data were collected during 1978-80.

SUBJECTS

Pregnant or lactating women in a rural farming community whose diet has been studied throughout the year.

RESULTS

Mean daily intake of vitamin C varied from virtually nil during the rainy season to about 100 mg/d in May, while plasma ascorbate ranged from 0.2 to 1.2 mg/dl, and breast-milk ascorbate from 2 to 6 mg/dl, changing synchronously with changing intake. Intake of retinol equivalents ranged from 120 micrograms/d in December to 900 micrograms/d in June, and plasma carotenoids showed synchronous fluctuation from 60 to 180 micrograms/dl, whereas plasma retinol was virtually unchanged throughout the year at 30 micrograms/dl. Intake of riboflavin was very low throughout the year, but erythrocyte glutathione reductase activation coefficient ranged from a minimum of 1.5 in July to a maximum of 1.9 between December and March. Obstetric outcome also exhibited seasonal variation with lowest birthweights during the rainy season. Intakes of food energy are assumed to be the major dietary influence on birthweight, but micronutrient intakes and status may have additional effects, and seasonality clearly affects ascorbate intakes by suckling infants.

CONCLUSIONS

In countries such as The Gambia seasonality is a major determinant of micronutrient status. However, dietary intake is not the only factor which determines micronutrient status: thus there are seasonal fluctuations in riboflavin status which, for example, may relate to changes in the balance between energy intake and output, rather than to seasonal changes in riboflavin intake.

The calcium and phosphorus intakes of rural Gambian women during pregnancy and lactation

The Ca and P intakes of 148 pregnant and lactating women in a rural village in The Gambia, West Africa, have been estimated by direct weighing of food on a total of 4188 d. The Ca and P contents of local foods were determined by analysis of raw ingredients, snack foods and prepared dishes. Information about the contribution of mineral-rich seasonings was obtained. Efforts were made to discover unusual sources of Ca that might not be perceived as food by subject or observer. The main contributors to daily Ca intake were shown to be leaves, fish, cereals, groundnuts and local salt. Cow's milk accounted for only 5% of Ca intake. Unusual sources of Ca were discovered, namely baobab (Adansonia digitata) fruit and selected earths, but these were consumed infrequently and their contributions to Ca intakes were small. Cereals and groundnuts were the main sources of P. Ca and P intakes (mg/d) were shown to average 404 (SD 110) and 887 (SD 219) respectively. Seasonal changes in the availability of leaves, cereals and groundnuts resulted in variations in Ca and P intakes. The rainy season was associated with increased Ca intakes (by 16%) but decreased P consumption (by 15%). No difference was observed in Ca intake between pregnant and lactating women but P intake in lactation was 11% higher than that in pregnancy during the post-harvest season. The implications of these low Ca intakes require investigation.

Riboflavin, folate and vitamin C status of Gambian women during pregnancy: a comparison between urban and rural communities

Anthropometric, haematological and vitamin status indices were measured in a group of pregnant women living in the urban community of Bakau in The Gambia, West Africa. Their haematological and anthropometric indices were generally within normal limits. Vitamin C status was also acceptable and was similar to values observed in rural Gambian women sampled at the same time of year. Folate status was similar to that seen previously in rural Gambian communities, and there was a strong intrasubject correlation between plasma and red cell folate levels, together with a trend towards higher values as pregnancy progressed. This was consistent with probable compliance with local recommendations for folate supplementation during pregnancy. The urban Gambian women also resembled their rural counterparts in having very poor biochemical riboflavin status, which deteriorated as pregnancy progressed. In this respect they differed markedly from UK women, who had satisfactory riboflavin status even in late pregnancy. The existence of severe biochemical riboflavin deficiency, even in urban Gambian women, whose anthropometric indices are not compatible with severe general malnutrition, suggests that a deficiency of this vitamin may be widespread in Sahelian West Africa. Measures to improve maternal vitamin status during pregnancy would therefore be equally appropriate in both rural and urban communities.

Etiology of rickets in Egyptian children

Factors associated with the rickets found in children attending the Outpatients Department of Cairo Children's Hospital have been studied. All the children studied were small for their age with the rachitic children being significantly smaller than the controls. The clinical diagnosis of the disease was confirmed in 54 children by X-ray and plasma biochemistry. The best indicator of the disease was the enlarged epiphysis of the wrist and to a lesser extent that of the ankles. Some of the factors predisposing to rickets were assessed in the rachitic children and in age-matched controls. There was no difference in the nutrient intake of these two groups of children although intakes of energy, calcium and vitamin D, but not of protein, were lower than recommended dietary allowances. Although more of the rachitic children came from urban areas than the controls there were no significant differences in the environments to account for the occurrence of the disease. Factors contributing to the development of rickets are discussed with particular regard to aspects such as low body weight, low maternal vitamin D status and low calcium intakes which cause a high rate of utilization and metabolism of vitamin D.

McCance and Widdowson's 'The composition of foods': supplementary information and review of new compositional data

Publications are reviewed which give detailed nutritional analyses of a wide range of representative samples of UK foods that have been undertaken since the publication of the fourth edition of McCance and Widdowson's 'The composition of foods'. These include trace elements, vitamin A, immigrant foods, cereals, milk and milk products and potatoes. Typographical corrections to the fourth edition are also given as well as the weight loss on cooking the recipe dishes.

The nutrient intakes of pregnant and lactating mothers of good socio-economic status in Cambridge, UK: some implications for recommended daily allowances of minor nutrients

1. Forty-two mothers from social classes I, II and III non-manual and twenty-one from social classes III manual M), IV and V were studied longitudinally. The mean daily nutrient intakes in months 4-9 of pregnancy, months 2-4 of lactation and 3 and 6 months post-lactation are presented and are compared with the UK and the US recommended daily allowances (RDA). 2. The quality of the diets (nutrients per 4184 kJ (1000 kcal] was found to be better than that of other adult female populations studied in the UK, except for a group of dietitians. 3. The mean daily intakes of nutrients for which there are UK RDA were almost all greater than 100% of the RDA. The exceptions were iron, which in the manual group (social classes IIIM, IV and V) was 85% of the RDA in pregnancy and 75% post-lactation, and vitamin D. 4. Among the nutrients for which there are US, but not UK RDA, only phosphorus and vitamin B12 intakes were greater than 100% of the RDA in both groups at all stages of the study. Intakes of other nutrients were below the RDA: pantothenate 70-91, vitamin B6, zinc, vitamin E and copper 40-72, folate 21-44, and biotin less than 20% of the RDA. 5. The bases of the RDA for adult women were examined; for most nutrients the information is limited. It was concluded that the RDA for magnesium, vitamin E and pantothenate are probably higher than necessary and that deficiency is unlikely; that zinc, copper, vitamin B6 and folate are probably 'marginal' nutrients for 'at risk' groups; and that information on biotin is insufficient even roughly to assess the dietary requirement.

Weaning practices in the United Kingdom and variations in anthropometric development

The influence of different weaning practices on the dietary energy intake and growth of Cambridge infants has been investigated. Bottle fed children were in general given solid foods sooner, 10.6 weeks for boys and 13.9 weeks with girls: among breast-fed babies the average age was 14.9 weeks in the case of boys and 17.4 weeks for girls. All four groups of children exhibited different growth patterns from those of the NCHS and Tanner reference curves. Over the first three months both boys and girls exhibited a faster velocity of growth in weight, length and weight-for-length. After this time, however, growth velocity was slower than that of the reference children particularly among breast-fed boys who were not given solids until after 16 weeks. For most of infancy triceps and subscapular skinfold thicknesses remained around the 10th centile of the corresponding Tanner reference children, although again the babies weaned later had the lower values. Bottle-fed infants had growth patterns similar to those of the earlier weaned breast-fed babies for all parameters. It is concluded that babies grow differently now that infant feeding patterns have changed.

Family food purchases and home food consumption: comparison of nutrient contents

Estimates of nutrient intakes based on food purchasing records modelled on the National Food Survey (NFS) were compared with nutrient intakes calculated from food consumption records based on a semi-weighted method, a combination of weighing and household measurement techniques. Of eighty-two families in Cambridge who completed the study, thirty-two were volunteers and fifty were from a random sample in which the co-operation rate was 73%. The estimated energy and nutrient contents of the Cambridge food purchases were very similar to those reported by the NFS for families of similar composition and income. The energy intakes obtained by the semi-weighed method were compared with results from twenty-five studies of energy intake based on quantitative measurements of food consumption: there was no evidence to suggest that the semi-weighed method consistently under- or overestimated intakes in the Cambridge subjects. Purchases adjusted to allow for waste and consumption of food by visitors contained significantly more energy, protein, carbohydrate, calcium, iron and dietary fibre than measured home food consumption. There was no significant difference in the nutrient content of purchases and consumption per 4.184 MJ (1000 kcal), with the exception of Fe and ascorbic acid. Measured wastage of edible food in thirty-one families averaged 3.2% of purchases. Estimate of wastage in all eighty-two families was 3.8%, and consumption of food by visitors accounted for 3.0% of purchases. The excess of purchases over measured home food energy intake is probably accounted for by a net increase in larder stocks rather than wastage, consumption of food by visitors, or under-recording of intakes.

Footnotes to food tables: 1. Differences in nutrient intakes of dietitians as calculated from the DHSS food tables and the fourth edition of McCance and Widdowson's 'The composition of foods'

The differences in nutrient intakes as calculated by two British food composition tables (those compiled by the Department of Health and Social Security in 1963 [DHSS] and the 4th edition of McCance and Widdowson's 'The composition of Foods' [MW4] were examined. Intakes of 43 dietitians who kept weighed diet records every sixth day for 3 to 12 months with 11 to 75 (mean 40) days' records per subject were calculated from each food table and compared in a loge tranformation. Mean per cent differences between intakes (delta x 100) were vitamin A, +23.3; vitamin D, + 21.1; riboflavin, + 16.0;calcium, +6.3; thiamin +4.8; niacin, +3.2 (MW4 higher) and protein, -1.7; fat, -3.5; energy, -3.6; carbohydrate, -6.0; vitamin C, -6.1; iron, -11.3; vitamin B6, -14.4 (MW4 lower). Correlation coefficients were: nicotinic acid, 0.84; vitamin B6, 0.86; other nutrients 0.90 to 0.99; thus differences between the two food tables in classifying individuals as high or low consumers were small. Mean intakes compared by paired t-test were significantly different (P less than 0.001) for all nutrients except nicotinic acid, indicating consistent differences in the food tables when applied to foods eaten by different individuals (nicotinic acid excepted). Mean intakes compared by one-tailed t-test -- as if the data came from independent surveys -- were significantly different/only for riboflavin/and vitamin/B6 (P less than 0.01), vitamin A and iron (P less than 0.05). For these nutrients, significant differences in intakes could be found between two surveyed populations due solely to the use of different food tables and not to differences in foods eaten. For the other nutrients studied, differences between the food tables were of little practical importance. Differences were due primarily to new analytical values in MW4 for riboflavin in milk, retinol in liver, iron in meats, vitamin B6 in many foods, and the use of margarine fortified with vitamins A and D in recipes. Major differences in the (high) nicotinic acid content of beer, instant coffee and specific breakfast cereals resulted in unpredictable differences in intakes of individuals.

Breast-milk antimicrobial factors of rural Gambian mothers. I. Influence of stage of lactation and maternal plane of nutrition

The concentrations of IgA, IgG, IgM, C3, C4, lactoferrin, lysozyme and secretory component in the mature breast milk of 152 rural Gambian mothers were measured up to 26 months lactation. The concentrations and daily secretion of all the immunoproteins, except lysozyme, decreased during the first year of lactation, but were well maintained thereafter. The production of lysozyme increased progressively throughout lactation. Compared with 10 mothers in Cambridge, U.K., the daily secretion of IgG, IgM, C3 and C4 was higher in The Gambia, that of IgA and lactoferrin was similar in the two communities, and that of lysozyme and secretory component was lower in The Gambia. A dietary supplement given to 90 Gambian mothers, raised the mean daily energy intake from a maximum of 1650 kcal/day and a hungry-season minimum of 1 200 kcal/day to 2 300 kcal/day throughout the study. The supplement did not enhance the production of breast milk immunoproteins.

The impact of malnutrition on human lactation: observations from community studies

There is very little scope for the direct examination of relationships between nutrient intake and lactational performance in women. Experimental investigations are limited to the effects of dietary supplementation in pregnancy and/or lactation. To obtain comparisons between normal and undernourished women, studies have to be performed at a community level. Studies in Cambridge, The Gambia, and elsewhere indicate that the impact of variations in nutrient intake on lactational performance is limited: over the ranges normally found in developed and developing countries milk output does not vary in relation to energy intake, and effects of nutrient intake on milk quality are restricted to increases in vitamin content after appropriate supplementation.

Growth charts and the assessment of infant feeding practices in the western world and in developing countries

Changes during the past ten years in infant feeding practices are described and it is demonstrated that with the growing popularity of breast feeding, plus the later addition of solids, dietary energy intakes are substantially lower than they were. These dietary changes would appear to be associated with alterations in the detailed pattern of growth. When exclusively breast-fed, babies, if anything, grow more quickly than growth standard rates, but after 3-4 months a relative deceleration in growth velocity becomes apparent. The anthropometric and dietary findings are discussed in relation to the use of growth charts for the assessment of the adequacy of infant feeding practices in the western world and especially in the Third World. A reanalysis of data indicates that diet-related growth faltering probably does not occur in many developing country situations until later than would be suggested by growth standards currently in use.

Seasonal variations in plasma retinol and carotenoid levels in rural Gambian women

Plasma carotenoid levels exhibited a major seasonal variation in pregnant and lactating women in Keneba, a rural Gambian village. This is probably due mainly to the seasonally related contribution of mangoes, which are a major dietary component during May and June, but are essentially unavailable for the remainder of the year. Plasma retinol levels, on the other hand, exhibited much less seasonal variation, although a trend towards higher levels in May and June was just discernible. Plasma retinol levels were significantly lower than those observed in a group of pregnant and lactating women living in the UK.

The nutritive contribution of school dinners and other mid-day meals to the diets of schoolchildren

In a dietary study of 112 Cambridge families, 191 primary and secondary school children kept 7-day records of measured food consumption. Of 955 weekday lunches recorded, 533 (56 per cent) were school dinners. School dinners provided less than one quarter of the recommended daily amount (RDA) for energy, iron and riboflavin, and less than one third of the RDA for protein, calcium, thiamin and ascorbic acid. School dinners provided a smaller proportion of a day's nutrient intake than did other mid-day meals. Total energy intakes were lower on school-dinner days than on other week-days. Children from lower income families had larger school dinners and obtained a larger proportion of their daily nutrient intake from school dinners than did children from higher income families. School dinners played their most important nutritional role in the lower income families.

Analytical versus food table values for vitamin C in foods: the effect on calculated vitamin C intake of elderly subjects

During a longitudinal study of vitamin C nutrition in 23 healthy elderly people, samples of cooked vegetables and liver, canned meats, canned vegetables and fruit drinks were analysed for vitamin C content. The analytical data are presented here and the effect on calculated daily intake of vitamin C of using the analytical values in place of food table values is assessed. For cooked foods the analysed values were close to food table values; exceptions were spring cabbage, cauliflower and canned potatoes. Fortified fruit drinks contained 20-60 mg vitamin C per 100 ml and made an important contribution to intake. Canned meats contained 0.3-61.4 mg per 100 g (mean 14.9 mg), but their contribution to intake was considered small. The difference between daily intakes calculated using analytical and food table values was greater than 5 mg in 37 per cent of 1-day periods and in 17 per cent of 7-day periods. These differences were not sufficient to significantly alter the correlations between intake and biochemical indices found in the original study. Nevertheless, given the discrepancies between calculated and analysed vitamin C intakes reported in the literature, analytical work is probably essential in studies of vitamin C nutrition.

Dietary supplementation of lactating Gambian women. I. Effect on breast-milk volume and quality

In order to test whether lactational capacity can be improved by dietary interventions, a nutritionally balanced supplement was provided under carefully controlled conditions to 130 nursing mothers in Keneba, The Gambia over 12 months. Maternal mean energy intake (+/- s.e.) increased from 1568 +/- 15 kcal/d (6.56 +/- 0.06 MJ/d) to 2291 +/- 14 kcal/d (9.59 +/- 0.06 MJ/d). Protein intake was in excess of the WHO/FAO recommended intake after supplementation and serious deficits of riboflavin, vitamin A, vitamin C and calcium were rectified. The supplement had no effect on breast-milk volume, compared with retrospective controls, at any stage of lactation or in any season of the year. There was no selective effect on women with poor milk outputs. The average milk protein concentration was slightly improved over the entire period of lactation (+ 6.6 per cent, P less than 0.01), but the total energy content was unchanged since an increase in breast-milk fat concentration (+ 7.9 per cent, n.s.) was offset by a decrease in the milk lactose concentration (- 7.6 per cent, P less than 0.01). Breast milk vitamin content was improved for those vitamins for which the supplement provided a significant proportion of the recommended dietary intake.

How much breast milk do babies need?

A reassessment of the breast milk requirements of young babies at different ages has been made from a statistical analysis of energy intake data collected prospectively in Cambridge, U.K. and from data derived from a literature survey of cross-sectional food energy intakes of infants from Canada, Sweden, the U.K. and USA. In contrast to the slow progressive linear decline in energy requirements per kg body-weight that has previously been assumed, measured intakes have been shown to fall more rapidly in the first six months of life. Thereafter they then rise again as the baby becomes more active. These findings are of fundamental importance to a realistic assessment of the adequacy of breast milk as the sole source of food in the first six months of life. The data show that typical breast milk intakes found in the industrialized countries can satisfy infant energy needs for healthy growth for much longer than would be indicated by current international dietary recommendations. A discussion of the physiological interpretation of the results is included as is an appraisal of their practical significance both to breast and bottle feeding practices.

Seasonal changes in activity, birth weight and lactational performance in rural Gambian women

The activity of 81 pregnant, lactating and non-pregnant, non-lactating women in the rural subsistence farming village of Keneba, The Gambia, was measured for 12 months using a combination of 24-hour activity recall and activity diaries. During the course of pregnancy women became gradually less active and in the month before giving birth were 25% less active than non-pregnant, non-lactating women and lactating women when women in the month after birth were excluded. There were striking seasonal changes in activity. During the dry season, from January to April, lactating women were active 55% of the 15-hour working day. At the start of the farming season in June and July this figure increased to 92%. Similar changes were observed in the pregnant women whose activity increased from a mean 50% in April to 83% in June. The period of intense activity coincided with a general shortage of food and increased incidence of disease. The intense activity of pregnant women in the farming season coupled with the low food intakes are most probably the main factors responsible for the striking fall in birth weights observed at this time of the year. Reduced lactational performance was apparent in relation to high activity when it necessitated the mother regularly spending much of the day away from her child. FAO/WHO-recommended energy intakes during pregnancy and lactation are inappropriate for this community.

Seasonal variations in ascorbic acid status and breast milk ascorbic acid levels in rural Gambian women in relation to dietary intake

Vitamin C intakes from mangoes and oranges, and plasma and breast milk ascorbic acid concentrations were measured at regular intervals in a cohort of pregnant and lactating women in Keneba and Manduar, two neighbouring rural Gambian villages. Extremely wide seasonal variations in plasma ascorbic acid levels were observed, the peak during the mango season in May and June attaining mean levels of 1.4 mg/dl, while the lowest levels, averaging only 0.2 mg/dl, were observed during the rainy season, during September and October. Parallel, but less pronounced variations were observed in breast milk ascorbate levels. A vitamin-fortified milk and biscuit supplement, given first to the lactating, and later to the pregnant, mothers in Keneba, which provided about 35 mg ascorbic acid per day, failed to produce any major improvement in plasma ascorbic acid levels during the rainy season, although there was some evidence for an improvement in breast milk levels. It is therefore likely that considerably greater intakes are required to maintain satisfactory maternal circulating levels and biochemical status during this critical period.

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

Riboflavin status was measured in infants between birth and two years of age, by the erythrocyte glutathione reductase (NAD(P)H2: glutathione oxidoreductase, EC 1.6.4.2) test on finger-prick blood samples. The infants were living in three rural Gambian villages: Keneba, Manduar and Kanton Kundar; those in Keneba were receiving a weaning food supplement between three and 12 months, which provided 0.15 to 0.20 mg riboflavin per day, in addition to their normal intake from breast milk and locally available weaning foods, which provided 0.13 to 0.21 mg/day over the same age range. On the basis of currently accepted criteria of biochemical normality, the unsupplemented infants were born deficient and, in the absence of a supplement, remained so throughout their first two years of life, with only a minor, short-lived improvement during the first few months. In the supplemented group, however, riboflavin status fell within normal limits for the duration of the supplement, but rapidly deteriorated again once the supplement was withdrawn. It is concluded that infants born to deficient mothers are usually deficient at birth, and remain so throughout suckling and weaning on to locally available foods. The daily requirement, to achieve satisfactory biochemical status, is thus greater than 0.13 to 0.21 mg/day, and probably approaches 0.4 mg/day, for most individuals up to the age of one year.

Long-term energy balance in child-bearing Gambian women

The energy intake of 143 pregnant and lactating Gambian women was measured prospectively each week for a year. Anthropometric, birth weight, and breast milk output measurements were also obtained. The average energy intakes (+/- SE) during the dry and wet seasons respectively were: pregnancy, 1483 +/- 22 and 1417 +/- 41 kcal/day; lactation (1st trimester), 1773 +/- 31 and 1474 +/- 42 kcal/day; lactation (subsequent trimesters), 1662 +/- 16 and 1413 +/- 37 kcal/day. Pregnant women gained 1.4 kg body weight per month in the dry season, but only 0.4 kg in the wet season. Lactating women gained weight in the dry season and lost weight in the wet season. Maternal nutritional status did not deteriorate with increasing parity. Mean birth weights (+/- SE) were: 2.94 +/- 0.07 and 2.78 +/- 0.11 kg in dry and wet seasons, respectively. Breast milk output and quality and early infant growth were close to values from well-nourished communities during the dry season, but deteriorated markedly during the wet season. Wet season energy intakes were clearly inadequate, but these results indicate that, despite being low by international standards, the dry season intake was compatible with a good lactational performance. Except for a somewhat low birth weight, which is partly explained by small maternal stature, progress during pregnancy was also remarkably normal during the dry season.