Crop production in most developing countries is faced with a dearth of resources for optimum production of which fertilizer is one. The use of human urine as well as its mixture with compost are potential solutions to this problem. Thus, this report investigated the influence of human urine and its combination with compost on yield and soil quality of land under green amaranths (Amaranthus caudatus). This study involved a field experiment to determine the response of green amaranths to the application of 100% urine, 2/3 urine N + 1/3 compost N, 100% compost N, NPK (15:15:15) at the rate of 100 kg N ha−1 and control with no fertilizer treatment using farmers’ participatory approach. The vegetables produced from the experimental treatments were analyzed in the laboratory for pathogenic microbial risk as well as effects of the fertilizer on nutrient status of the experimental soils (before and after planting). Perception of farmers and consumers in the study area regarding use of urine as fertilizer for vegetable production was investigated with the aid of a structured questionnaire. The result of this investigation revealed that 100% urine resulted in 58.17 t ha−1 total plant yield, while NPK 15:15:15 gave 34.34 t ha−1 total plant yield in the two plantings. Microbial analysis of edible portion of vegetable from plot fertilized with urine did not reveal any significantly different pathological contamination compared to other fertilizer treatments used in this investigation. Urine treatment improved soil nutrient exchangeable cations and acidity. The perception study revealed that respondents perceived urine to be a good agricultural input that could be used as a fertilizer in vegetable crop production and there was no strong cultural norm that would prevent them using it for crop production. Vegetable consumers would also buy vegetable crops grown with urine if they are well informed about its safety for crop production. Since the use of urine as fertilizer for crop production improved amaranth's yield and did not show any negative implication on soil environment, human urine seems to have good potential both in crop yield and acceptability by farmers and consumers.

Nutritional assessments are frequently based on amounts of nutrients consumed. In the present paper the usefulness of nutrient intake data for assessing nutrient adequacy is examined in an elderly British population. Subjects were ‘free-living’ elderly aged 68-90 years (sixty men, eighty-five women) in Norwich. Forty-two of forty-nine surviving males and sixty-seven of seventy-nine surviving females were reassessed after 2 years. With few exceptions, estimated micronutrient intake was not statistically predictive of biochemical measures of nutrient adequacy. Initial biochemical measures of nutritional adequacy were compared with those found 2 years later in an attempt to assess whether initial biochemical assessment was predictive of the ‘longer term’situation. Biochemical measurements at the start of the study were correlated to the same measurements made 2 years later for: serum ferritin, haemoglobin and erythrocyte count, whole-blood Se-glutathione peroxidase (EC 1.11.1.9; males only), plasma Cu, alkaline phosphatase (EC 3.1.3.1), ascorbic acid, vitamin B6 (pyridoxal-5-phosphate), folate and vitamin B12, total erythrocyte thiamin (males only), riboflavin (erythrocyte glutathione reductase (EC 1.6.4.1) activation coefficient): but not for: erythrocyte Cu-superoxide dismutase (EC 1.15.1.1) or plasma Zn. Either only small changes, or no changes, in mean values were seen over the 2 years for most of the biochemical measures. One exception was a large increase in plasma folate. The only important ‘negative’ features seen at 2-year follow up were a large fall in serum ferritin concentration and a large increase in the activity of two antioxidant defence enzymes, superoxide dismutase and glutathione peroxidase. As judged by currently accepted biochemical deficiency threshold values, asmall proportion of subjects were possibly at risk of Fe (3% men; 1% women), folate (7%, 3%), thiamin (12%;3%) and vitamin C (15%; 17%) deficiency. Many more appeared to be at risk of vitamin B6 (42%; 47%) and riboflavin (77%; 79%) deficiency. It was concluded that the requirements of the elderly for vitamins B1, B2 and C, and the biochemical deficiency threshold vahes used to indicate vitamin B6 deficiency, need review

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 1.11.1.9) activity and non-verbal and verbal IQ 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.