The American journal of clinical nutrition
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Randomized Controlled Trial Comparative Study
Dietary calcium does not interact with vitamin D₃ in terms of determining the response and catabolism of serum 25-hydroxyvitamin D during winter in older adults.
Interactions between calcium and vitamin D may have implications for the regulation of serum 25-hydroxyvitamin D [25(OH)D] and its catabolism and, consequently, the vitamin D dietary requirement. ⋯ We found no evidence of a vitamin D sparing effect of high calcium intake, which has been referred to by some authors as "vitamin D economy." Thus, recent dietary vitamin D requirement estimates will cover the vitamin D needs of even those individuals who have inadequate calcium intakes.
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Randomized Controlled Trial Multicenter Study
Placement and promotion strategies to increase sales of healthier products in supermarkets in low-income, ethnically diverse neighborhoods: a randomized controlled trial.
The greater presence of supermarkets in low-income, high-minority neighborhoods has the potential to positively affect diet quality among those at greatest risk of obesity. In-store marketing strategies that draw attention to healthier products may be effective, sustainable, and scalable for improving diet quality and health. Few controlled studies of in-store marketing strategies to promote sales of healthier items in low-income, high-minority neighborhoods have been conducted. ⋯ These data indicate that straightforward placement strategies can significantly enhance the sales of healthier items in several food and beverage categories. Such strategies show promise for significant public health effects in communities with the greatest risk of obesity.
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Randomized Controlled Trial Comparative Study
Dose response to vitamin D supplementation in African Americans: results of a 4-arm, randomized, placebo-controlled trial.
Association studies have suggested that lower circulating 25-hydroxyvitamin D [25(OH)D] in African Americans may partially underlie higher rates of cardiovascular disease and cancer in this population. Nonetheless, the relation between vitamin D supplementation and 25(OH)D concentrations in African Americans remains undefined. ⋯ Within African Americans, an estimated 1640 IU vitamin D₃/d was required to achieve concentrations of plasma 25(OH)D recommended by the Institute of Medicine, whereas 4000 IU/d was needed to reach concentrations predicted to reduce cancer and cardiovascular disease risk in prospective observational studies. These results may be helpful for informing future trials of disease prevention.
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Randomized Controlled Trial
Does behavioral intervention in pregnancy reduce postpartum weight retention? Twelve-month outcomes of the Fit for Delivery randomized trial.
Excessive weight gain during pregnancy is a risk factor for postpartum weight retention and future weight gain and obesity. Whether a behavioral intervention in pregnancy can reduce long-term weight retention is unknown. ⋯ A low-intensity behavioral intervention in pregnancy can reduce 12-mo postpartum weight retention and improve dietary restraint and self-weighing in study completers. Future research is needed to test the long-term effects of more intensive behavioral interventions in pregnancy. This trial was registered at clinicaltrials.gov as NCT01117961.
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Randomized Controlled Trial
Effect of vitamin D supplementation on antibiotic use: a randomized controlled trial.
Observational data suggested that supplementation with vitamin D could reduce risk of infection, but trial data are inconsistent. ⋯ Although this study was a post hoc analysis and statistically nonsignificant, this trial lends some support to the hypothesis that supplementation with 60,000 IU vitamin D/mo is associated with lower risk of infection, particularly in older adults. The trial was registered at the Australian New Zealand Clinical Trials Registry (anzctr.org.au) as ACTRN12609001063202.