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 ...

BACKGROUND The Institute of Medicine 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D specified higher intakes for all age groups compared to the 1997 report, but also cautioned against spurious claims about an epidemic of vitamin D deficiency and against advocates of higher intake requirements. Over 40 years, we have noted marked improvement in vitamin D status but we are con...

BACKGROUND AND PURPOSE Morphological brain changes related to hypovitaminosis D have been poorly studied. In particular, the age-related decrease in vitamin D concentrations may explain the onset of white matter abnormalities (WMA) in older adults. Our objectives were (i) to investigate whether there was an association between serum 25-hydroxyvitamin D (25OHD) concentration and the grade of WMA...

OBJECTIVE To assess whether higher 25-hydroxyvitamin D (25OHD) levels are associated with subsequent better immune responses to hepatitis B and Streptococcus pneumoniae vaccination in HIV-infected patients. METHODS 25OHD was measured on stored baseline plasma samples from two randomized vaccine trials in HIV-infected adults: the ANRS HB03 VIHVAC B trial and an immunological sub-study of the A...

INTRODUCTION Biological evidence suggests that vitamin D might be involved in regulating mood. The relationship between 25-hydroxyvitamin D (25OHD) and the onset of depressive symptoms was examined over a 4.4-year follow-up in a sample of older adults. METHODS This research was part of the Progetto Veneto Anziani (Pro.V.A.), an Italian population-based cohort study on a total of 1,039 women a...

Vitamin D status and associated metabolism during pregnancy and lactation have been assessed in only a limited number of longitudinal studies, all from the northern hemisphere, with no infant data concurrently reported. Therefore, we aimed to describe longitudinal maternal and infant 25-hydroxy vitamin D (25OHD) and parathyroid hormone (PTH) status during pregnancy and up to 5 months postnatal ...

OBJECTIVES To determine the possible association of serum 25-hydroxyvitamin D (25OHD) levels with disease activity and respiratory infection in granulomatosis with polyangiitis patients during two different periods: winter/spring and summer/autumn. METHODS Thirty-two granulomatosis with polyangiitis patients were evaluated in the winter/spring, and the same patients (except 5) were evaluated ...

BACKGROUND Preoperative anemia is considered an independent risk factor of poor clinical outcome in cardiac surgical patients. Low vitamin D status may increase anemia risk. METHODS We investigated 3,615 consecutive patients scheduled for cardiac surgery to determine the association between preoperative anemia (hemoglobin [Hb] <12.5 g/dL) and circulating levels of the vitamin D metabolites 25...

OBJECTIVE To determine parathyroid hormone (PTH) reference values in French healthy adults, taking into account serum 25-hydroxyvitamin D (25OHD), renal function, age, gender, and BMI. PARTICIPANTS AND MAIN BIOLOGICAL MEASUREMENTS We studied 898 healthy subjects (432 women) aged 18-89 years with a normal BMI and estimated glomerular filtration rate (eGFR), 81 patients with surgically proven p...

BACKGROUND Serum 25-hydroxyvitamin D (25OHD) is a key factor in determining monocyte induction of the antimicrobial protein cathelicidin, which requires intracrine conversion of 25OHD to 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. Both vitamin D metabolites circulate bound to vitamin D-binding protein (DBP), but the effect of this on induction of monocyte cathelicidin remains unclear. METHODS Hum...