To the Editor: In an article of 2007 about vitamin D deficiency, it was reported that low 25OH-vitD (25hydroxyvitaminD) plasma levels are found in thyrotoxicosis, with thyrotoxicosis being the last in the list of acquired causes of vitamin D deficiency (1). We first demonstrated low 25OH-vitD plasma levels in thyrotoxicosis (2), as well as the fact that the transformation of vitamin D into 25OH...

Key circulating molecules that link vitamin D (VD) to pediatric obesity and its co-morbidities remain unclear. Using a proteomic approach, our objective was to identify key molecules in obese children dichotomized according to 25OH-vitamin D (25OHD) levels. A total of 42 obese children (M/F = 18/24) were divided according to their 25OHD3 levels into 25OHD3 deficient (VDD; n = 18; 25OHD<15 ng/ml...

BACKGROUND The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multi-center study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique. METHODS One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vi...

Obesity is often associated with vitamin D deficiency and secondary hyperparathyroidism. Vitamin D supplementation typically leads to the reductions in serum parathyroid hormone (PTH) levels, as shown in normal weight individuals. Meanwhile, the dose of vitamin D supplementation for the suppression of PTH may differ in overweight and obese adults. We conducted a systematic review and meta-analy...

assay on the Roche Modular analyzer. They used clinical samples that were almost free of 25hydroxyvitamin D2 (25-OH-D2) ( 10 nmol/L) as confirmed by liquid chromatography–tandem mass spectrometry (LC-MS/MS) and found a good overall agreement between the results obtained with the Roche assay and those measured with the DiaSorin RIA and by LC-MS/MS. Although they acknowledged that the Roche assay...

Vitamin D deficiency is an important problem in patients with chronic conditions including those with human immunodeficiency virus (HIV) infection. The aim of this cross-sectional study was to identify the prevalence and factors associated with vitamin D deficiency and hyperparathyroidism in HIV patients attended in Barcelona. Cholecalciferol (25OH vitamin D3) and PTH levels were measured. Vita...

To study vitamin D (25OH D3 ) in relation to (i) microbial translocation (ii) systemic inflammation and (iii) blood lipid markers, in Caucasian, well-controlled HIV patients and healthy controls, plasma and serum samples from n = 97 male, HIV patients on HAART with immeasurable viral load (<20 copies/ml) since median 6.5 years and no concurrent inflammatory or infectious disease and n = 30 heal...

Although hip fracture is considered to be associated with hypovitaminosis D and K, few reports have previously studied both of them. We have studied the vitamin D- and K-status as well as the general nutritional status in ninety-nine patients with hip fracture. Mean serum concentration of 25hydroxy-vitamin D (25OH-D) in female fractured patients was only approximately 9 ng/mL, suggesting severe...

Background: Epilepsy is a chronic condition with an incidence of 4–10/1,000 worldwide, Antiepileptic drugs (AED) in common use are carbamazepine (CBZ), phenytoin (DPH), phenobarbitone (PB), and sodium valproate. The effect of AEDs on the vitamin D metabolism is of considerable value especially in children. There are few clinicians who use prophylactic calcium or vitamin D for patients taking AE...

BACKGROUND Vitamin D testing is increasing worldwide. Recently several diagnostic manufacturers including Abbott and Siemens have launched automated 25-hydroxy vitamin D (25OH-D) immunoassays. Furthermore, preexisting assays from DiaSorin and Roche have recently been modified. We compared the performance of 5 automated immunoassays, an RIA and 2 liquid chromatography-tandem mass spectrometry (L...