The American journal of clinical nutrition
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Randomized Controlled Trial
Estimation of the dietary requirement for vitamin D in white children aged 4-8 y: a randomized, controlled, dose-response trial.
Children in northern latitudes are at high risk of vitamin D deficiency during winter because of negligible dermal vitamin D3 production. However, to our knowledge, the dietary requirement for maintaining the nutritional adequacy of vitamin D in young children has not been investigated. ⋯ Vitamin D intakes between 8 and 20 μg/d are required by white 4- to 8-y-olds during winter in northern latitudes to maintain serum 25(OH)D >30-50 nmol/L depending on chosen serum 25(OH)D threshold. This trial was registered at clinicaltrials.gov as NCT02145195.
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Moderate-to-vigorous-intensity physical activity is recommended to maintain and improve health, but the mortality benefits of light activity and risk for sedentary time remain uncertain. ⋯ Health promotion efforts for physical activity have mostly focused on moderate-to-vigorous activity. However, our findings derived from accelerometer-based measurements suggest that increasing light-intensity activity and reducing sedentary time are also important, particularly for inactive adults.
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Randomized Controlled Trial
Estimation of the dietary requirement for vitamin D in adolescents aged 14-18 y: a dose-response, double-blind, randomized placebo-controlled trial.
Adolescents are a population group at high risk of low vitamin D status, yet the evidence base for establishing dietary vitamin D requirements remains weak. ⋯ Vitamin D intakes between 10 and ∼30 μg/d are required by white adolescents during winter to maintain serum 25(OH)D concentrations >25-50 nmol/L, depending on the serum 25(OH)D threshold chosen. This trial was registered at clinicaltrials.gov as NCT02150122 and as International Standard Randomized Controlled Trial Number ISRCTN40736890.
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Although a strong biological basis exists for a role of iodine in somatic growth failure in childhood, this relation has not been previously studied on a large scale to our knowledge. ⋯ Although we did not establish causality in our analysis, the findings might indicate that the causal effect of iodized salt on child growth, if it exists, is most profound in utero and is not universally effective across all countries with respect to longer-run child-growth outcomes such as stunting and underweight.
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Studies on the association between body mass index (BMI) and colorectal cancer (CRC) prognosis after diagnosis have yielded inconsistent results. Few studies have investigated associations between prediagnostic BMI change and CRC prognosis. ⋯ Overweight and obesity are associated with enhanced survival after a CRC diagnosis. A major decrease in BMI in the years before diagnosis is a strong independent predictor of decreased survival. This trial was registered at www.studybox.de as ST-D066.