This article discusses the amount of vitamin D supplementation needed and the desirable 25-hydroxyvitamin D level to be achieved for optimal fracture prevention.

OBJECTIVES Analytical and clinical verification of both old and new generations of the Abbott total 25-hydroxyvitamin D (25OHD) assays, and an examination of reference Intervals. METHODS Determination of between-run precision, and Deming comparison between patient sample results for 25OHD on the Abbott Architect, DiaSorin Liaison and AB SCIEX API 4000 (LC-MS/MS). Establishment of uncertainty ...

The objectives of this work were: (1) To determine whether repeated exposures to small doses from a commercial sun bed (Wolff Solarium Super Plus 100 W) over 5 weeks gave less vitamin D than repeated exposures to twice as large, but still nonerythemogenic, doses. (2) To investigate whether the contribution to the vitamin D status from such sessions of exposures was dependent on the baseline sta...

AIMS The present study investigated whether sociodemographic factors and physical activity (PA) are associated with differences in serum 25-hydroxyvitamin D [25(OH)D] levels and whether these differences are associated with varying levels of endurance performance and body mass index (BMI) in children and adolescents. SUBJECTS AND METHODS Path analyses were based on data of a nationwide, cross...

Cryptomys hottentotus has no access to dietary or endogenous sources of cholecalciferol (D3). Serum concentrations of calcifediol (25(OH)D3) were undetectable (< 5 ng/ml) and calcitriol (1,25(OH)2D3), although detectable in plasma, was at a low concentration (31.40 (SEM 3.06 pg/ml). Despite their naturally impoverished vitamin D status, these animals exhibited highly efficient mineral absorptio...

OBJECTIVE To investigate whether relationships exist among vitamin D, type 2 diabetes mellitus (T2DM), and blood pressure in Trinidadian subjects with T2DM. RESEARCH DESIGN AND METHODS This was a case-controlled study to determine if vitamin D levels were lower in patients with T2DM. After data analysis, an exploratory hypothesis of vitamin D relationship to systolic blood pressure (SBP) was ...

Alteration in vitamin D metabolism has a central role in the pathogenesis of secondary hyperparathyroidism (SHPT) and is also associated with increased cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). For more than sixty years, vitamin D, nutritional vitamin D (ergocalciferol, cholecalciferol or calcifediol) and nonselective vitamin D receptor (VDR) activato...

BACKGROUND AND OBJECTIVES Assay cost, quality, and availability pose challenges for vitamin D surveys in limited resource settings. This study aimed to validate an inexpensive vitamin D assay (ELISA) under real-world conditions in Mongolia, the northernmost developing country, to characterize the assay's usefulness and inform the design of epidemiologic studies in similar regions. METHODS AND...

BACKGROUND Inadequate photosynthesis or oral intake of Vitamin D are associated with high incidence rates of colorectal cancer, but the dose-response relationship has not been adequately studied. METHODS Dose-response gradients from observational studies of Vitamin D intake and serum 25-hydroxyvitamin D were plotted as trend lines. The point on each linear trend line corresponding to an odds ...