Christine D. Thomson

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OBJECTIVE The intent of this review is to evaluate the scientific evidence for the assessment of adequacy of selenium status and of the requirements for selenium. From this evidence, attempts have been made to define levels of plasma selenium and dietary selenium intake, which could be used for the assessment of deficiency or adequacy of selenium status. (More)
BACKGROUND Current US dietary recommendations for selenium are based on maximization of plasma glutathione peroxidase (GSHPx) activity according to data from one study of Chinese men. OBJECTIVE The effect of various amounts of supplemental selenium on GSHPx activities in blood of New Zealand adults was investigated to calculate a selenium requirement for(More)
Thirty-three New Zealand women aged 18-23 years received daily for 32 weeks, 200 micrograms Se as Se-enriched yeast (selenomethionine), or brewer's yeast mixed with selenate, or no added Se (placebo) in a double-blind trial. Se supplementation raised (P = 0.001) platelet glutathione peroxidase (EC; GSHPx) activity, and also Se and GSHPx in whole(More)
OBJECTIVE The aim of this paper was to compile all the studies of selenium status carried out in Otago and in other areas of New Zealand in order to follow the history of selenium status in New Zealand residents over the last 20 years. DESIGN Since 1970 baseline blood samples have been collected from several groups of healthy adult subjects, either for(More)
Evidence is accumulating to suggest that selenium (Se) is an essential trace element for man and is reviewed with emphasis on those aspects peculiar to New Zealand. The extremely low Se levels in New Zealand soils results in a low Se content of foods, low dietary intakes, low urinary excretions, and low blood Se concentrations and glutathione peroxidase(More)
The aim of this study was to establish methodology for a survey of the iodine and selenium status of New Zealand residents, more specifically to investigate the correlation between fasting or random casual urine samples and 24 hour urines for iodine and selenium excretion. Sixty-two (31 M, 31 F) adults collected casual, fasting and 24 hour urine samples for(More)
BACKGROUND Brazil nuts provide a rich natural source of selenium, yet no studies have investigated the bioavailability of selenium in humans. OBJECTIVE We investigated the efficacy of Brazil nuts in increasing selenium status in comparison with selenomethionine. DESIGN A randomized controlled trial was conducted with 59 New Zealand adults. Participants(More)
The blood selenium (Se) concentrations of New Zealand children were lower than those reported for children living in other countries. This low blood Se was primarily determined by the low dietary intake of the children which, in turn, reflects the low Se content of New Zealand soils. Blood Se also varied geographically, with age, and with differences in(More)
The relationship of whole blood selenium (Se) to glutathione peroxidase (GPX) activity was examined for individuals in New Zealand, Oregon, and South Dakota who represented, respectively, populations with exposure to low, medium, and high amounts of Se. The mean (respective) blood Se levels were 60, 200, and 400 ng/ml. Intergroup differences in blood Se(More)
This study was carried out in Otago, South Island, where most arable land has a low soil selenium content (less than 0.5 microgram/g) and where selenium (Se) responsive diseases in livestock are common. Se concentration in whole blood, erythrocytes and plasma, and activity of glutathione peroxidase (EC were measured in blood from 104 healthy Otago(More)