The plasma disappearance of intravenously administered tracer doses of tritium-labelled 25-hydroxyvitamin D3 (25OHD3) wa studied in six normal subjects and in 15 patients with intestinal malabsorption. The plasma half-life was significantly shorter and the clearance rate significantly greater in the group with malabsorption compared with the controls. One explanation for this increased eliminat...

BACKGROUND Vitamin D deficiency has become prevalent worldwide in recent years. However, less evidence was available for lactating women. OBJECTIVE The purpose of the study was to understand vitamin D status and prevalence of deficiency in lactating women and associated risk factors for vitamin D deficiency from eight provinces and municipalities in China. METHODS Lactating women within 1-1...

INTRODUCTION Vitamin D deficiency has been associated with increased risk of colorectal cancer (CRC), but causal relationship has not yet been confirmed. We investigate the direction of causation between vitamin D and CRC by extending the conventional approaches to allow pleiotropic relationships and by explicitly modelling unmeasured confounders. METHODS Plasma 25-hydroxyvitamin D (25-OHD), ...

BACKGROUND Excess adipose tissue may lead to sequestrating of vitamin D, making it less available for use in the body. OBJECTIVE This study determined if overweight or obese individuals (BMI > 25 kg m-2) had insufficient (<30 ng mL-1) levels of 25-hydroxyvitamin D [25(OH)D] and, if so, would serum levels respond to exogenous supplementation. METHODS Sixty-three women who were overweight/obe...

The principal questions about the vitamin D topic are far to be resolved: in which children 25-hydroxyvitamin D blood testing is appropriate and how much cholecalciferol should be given in the absence of the test? Analyzing vitamin D status in a group of children cared by a "family pediatrician" in northeastern Italy we noted a high incidence of deficiency in asymptomatic preschool children wit...

The vitamin D content of eggs from three retail outlets was measured over five months to examine the effects of production system (organic vs. free range vs. indoor), supermarket and purchase date on the concentration of vitamin D3 and 25-hydroxyvitamin D3. Results demonstrated a higher vitamin D3 concentration in free range (57.2±3.1μg/kg) and organic (57.2±3.2μg/kg) compared with indoor (40.2...

OBJECTIVES This study aimed to evaluate the relationship between the 25-hydroxyvitamin D [25(OH)D] level and rheumatoid arthritis (RA) and the correlation between serum vitamin D level and RA activity. METHODS We searched the PUBMED, EMBASE, and Cochrane databases and performed a meta-analysis examining the vitamin D level and prevalence of vitamin D deficiency in patients with RA compared to...

Vitamin D deficiency/insufficiency is prevalent among pregnant women. Recommendations for adequate levels of circulating 25-hydroxyvitamin D and appropriate vitamin D supplementation during pregnancy differ between the Institute of Medicine and the Endocrine Society. Obstetrician-gynecologists must make clinical decisions in this environment of uncertain guidance. An online questionnaire regard...

Plasma 25-hydroxy-cholecalciferol (25-OHD) was measured serially in two groups of preterm infants receiving either 400 IU or 1000 IU oral vitamin D3 daily. All the babies were able to absorb and hydroxylate vitamin D3 adequately by 36 weeks' gestational age. The higher daily supplement had no advantage over the lower dose.

The aim of the study was to investigate serum 25-hydroxyvitamin D (25(OH) D3) levels in patients with vitiligo vulgaris in terms of causal relation and extension of the disorder. This study is a clinical cross-sectional study carried out in order to determine 25-hydroxyvitamin D levels among 25 patients with vitiligo vulgaris and in 41 controls. Fitzpatrick skin phototypes, history of autoimmun...