The Journal of clinical endocrinology and metabolism
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J. Clin. Endocrinol. Metab. · Dec 2013
Randomized Controlled Trial Multicenter Study Comparative StudyA randomized trial of vitamin D₃ supplementation in children: dose-response effects on vitamin D metabolites and calcium absorption.
Changes in serum vitamin D metabolites and calcium absorption with varying doses of oral vitamin D₃ in healthy children are unknown. ⋯ Large increases in serum 25(OH)D with vitamin D₃ supplementation did not increase calcium absorption in healthy children living at 2 different latitudes. Supplementation with 400 IU/d was sufficient to maintain wintertime 25(OH)D concentrations in healthy black, but not white, children.
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J. Clin. Endocrinol. Metab. · Dec 2013
Randomized Controlled Trial25-Hydroxyvitamin D response to graded vitamin D₃ supplementation among obese adults.
Guidelines have suggested that obese adults need 2 to 3 times more vitamin D than lean adults to treat vitamin D deficiency, but few studies have evaluated the vitamin D dose response in obese subjects. ⋯ Our data show that in obese people, the 25(OH)D response to vitamin D₃ is directly related to dose and body size with ∼2.5 IU/kg required for every unit increment in 25(OH)D (nanograms per milliliter).