Relationships between micronutrient intake and status, and micronutrient status and performance in tests of intelligence were investigated in a group of adolescents (13-14 years old). Dietary intakes were assessed using a 7 d weighed dietary record method, coupled with the collection of duplicate diets.Vitamin and trace mineral intakes calculated using food composition tables were compared with those obtained by direct analysis of duplicate diets. Micronutrient status was judged via a range of biochemical indices measured in blood samples taken after a 12-15 h fast. Blood samples were taken both before and after a 16-week period of vitamin and trace mineral supplementation. Individual tests of verbal and nonverbal intelligence were also performed pre-and post-supplementation. The results of this study indicate that the use of food table data may lead to substantial over-or underestimation of the intake of several micronutrients. In general, the total calculated or analysed amount of a specific micronutrient consumed did not adequately predict status, as judged by a range of biochemical indices. There were significant changes in status measurements over the 16-week study period, irrespective of supplementation, and these changes were markedly influenced by the initial status of the subject. There was no effect of supplementation on performance in tests of intelligence. However, there was a significant association between plasma ascorbic acid and initial non-verbal intelligence quotient (IQ) in the boys, and between whole blood glutathione peroxidase (EC 1 . 11 . I .9) activity and non-verbal and verbal 1Q in both sexes.These findings are discussed in relation to other recent studies of the influence of micronutrient supplementation on the psychological performance of children.

The present paper is an analysis of 138 5-or 7-d diet diaries collected from a free-living population of people aged 68-90 years in Norwich. Men had higher intakes than women of energy and most nutrients, but patterns of variation across the week were similar for both sexes. Intakes of meat, meat products, fish and vegetables varied across the week both in frequency and amount eaten, but the other main food groups showed no significant variation. Alcohol was taken more frequently at weekends but the amount did not vary significantly. Intakes of energy, protein and many micronutrients varied significantly with day of the week, with increased intake at weekends, especially of vegetable-derived micronutrients on Sundays, and generally decreased intake on Mondays and Fridays. Nutrient densities of carotene, retinol equivalents, folate, vitamin C, pantothenate and Zn yere all highest on Sundays, providing further evidence of variation of diet quality on different days;of the week.

The relationship between vitamin C intake and status was investigated in a group of adolescents (13-14 years old). Dietary intakes were assessed using a 7 d weighed dietary record method, coupled with the collection of duplicate diets. Vitamin C intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Vitamin C status was judged via measurement of plasma ascorbic acid (AA) concentration in blood samples taken after a 12-15 h fast. The relationship between calculated and analysed vitamin C intake and plasma AA concentration was examined. Average daily calculated vitamin C intakes, for the group (n 54) as a whole over a 7 d period, gave a good estimate of intake, as judged by prompt analysis of duplicate diets. However, analysed u. calculated intakes were significantly different for approximately one-third of subjects when data were examined on an individual basis. Large discrepancies between analysed and calculated values could not be accounted for on a food group basis. In all but two individuals, calculated vitamin C intake was in excess of the new reference nutrient intake (RNI, part of the new daily reference values (Department of Health and Social Security, 1991)) of 40 mg and all plasma AA concentrations were well above those used to indicate even a moderate risk of deficiency. A relationship between vitamin C intake and plasma AA was observed for both males (n 19) and females (n 35). However, the relationship was much stronger for males who showed a wider range of both intake and plasma AA values.

The National Food Survey provides a valuable supply of information on the intake of food and nutrients in the British diet (Derry & Bus, 1984), but is confined to foods brought into the home. The present study examined nutrient contribution from foods eaten outside the home to the overall diet. Seventy subjects (35 males and 35 females), were selected from a local health centre register, using age and sex as criteria, and asked to keep a written record of everything consumed for three days. There was a very high percentage of all subjects eating out over the three days. There was a very high percentage of all subjects eating out over the three days, but most of this food could be classed as ‘casual’, or of the ‘non‐meal’ category i.e. snacks. Employment was a significant determinant of frequency of eating out. The food groups contributing more highly to nutrient intake away from home were meats, sugars and preserves, alcoholic beverages, fish and chips. Energy from sugar, measured as sugar density, was significantly higher in ‘away’ foods, but fibre density and protein as a percentage of energy was higher in foods eaten at home. The percentage energy form nutrients to total energy did not differ greatly when alcoholic beverages were excluded from the data, apart from redistribution of the energy from alcohol between the other nutrients. The results show that foods eaten outside the future research on ‘out of home’ eating habits would benefit from inclusion of nutritional analysis.

Birmingham 5-methyltetrahydrofolate, the most bioavailable folate was measured by highperformance liquid chromatography in the British total diet study, a survey designed primarily to monitor food contaminants. A total 5 MeTHF of 130.1 pg (k21.7, n=6) was measured in the food groups which made up the average daily food intake. This value compares well to the estimated average requirement (EAR) of folate recently set by the Department of Health at 150 pg/day. The survey present here is an accurate reflection of folate consumed as all food samples were prepared ready for consumption. Key words:British total diet study, estimated average requirement, folates, high-performance liquid chromatography, 5-methyltetrahydrofolate. 1983).Since then the survey has been reorganized twice to allow both for improvements in sampling and holding techniques and changes in the eating habits of the British population. Originally, the study was introduced to investigate the possibility of pesticide and then heavy metal contamination. However, the randomized allocation of some 120 different foods into 20 different groups, prepared ready for consumption, also provides an excellent opportunity for estimating intake of nutrients. We have now analysed these for 5-methyltetrahydrofolate (SMeTHF),

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