30 research outputs found

    Vitamin D inadequacy in Belgian postmenopausal osteoporotic women

    Get PDF
    BACKGROUND: Inadequate serum vitamin D [25(OH)D] concentrations are associated with secondary hyperparathyroidism, increased bone turnover and bone loss, which increase fracture risk. The objective of this study is to assess the prevalence of inadequate serum 25(OH)D concentrations in postmenopausal Belgian women. Opinions with regard to the definition of vitamin D deficiency and adequate vitamin D status vary widely and there are no clear international agreements on what constitute adequate concentrations of vitamin D. METHODS: Assessment of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone was performed in 1195 Belgian postmenopausal women aged over 50 years. Main analysis has been performed in the whole study population and according to the previous use of vitamin D and calcium supplements. Four cut-offs of 25(OH)D inadequacy were fixed : < 80 nmol/L, <75 nmol/L, < 50 nmol/L and < 30 nmol/L. RESULTS: Mean (SD) age of the patients was 76.9 (7.5) years, body mass index was 25.7 (4.5) kg/m(2). Concentrations of 25(OH)D were 52.5 (21.4) nmol/L. In the whole study population, the prevalence of 25(OH)D inadequacy was 91.3 %, 87.5 %, 43.1 % and 15.9% when considering cut-offs of 80, 75, 50 and 30 nmol/L, respectively. Women who used vitamin D supplements, alone or combined with calcium supplements, had higher concentrations of 25(OH)D than non-users. Significant inverse correlations were found between age/serum PTH and serum 25(OH)D (r = -0.23/r = -0.31) and also between age/serum PTH and femoral neck BMD (r = -0.29/r = -0.15). There is a significant positive relation between age and PTH (r = 0.16), serum 25(OH)D and femoral neck BMD (r = 0.07). (P < 0.05) Vitamin D concentrations varied with the season of sampling but did not reach statistical significance (P = 0.09). CONCLUSION: This study points out a high prevalence of vitamin D inadequacy in Belgian postmenopausal osteoporotic women, even among subjects receiving vitamin D supplements

    The non-immunosuppressive management of childhood nephrotic syndrome

    Get PDF

    Method for simultaneous analysis of eight analogues of vitamin D using liquid chromatography tandem mass spectrometry

    Get PDF
    Background Despite considerable global investigation over several decades, the roles of vitamin D in health and disease development remains convoluted. One recognised issue is the difficulty of accurately measuring the active forms of vitamin D. Advances made include some new methods addressing the potential interference by excluding epimers and isobars. However, there is no evidence that epimers are without function. Therefore, the aim of this study was to develop and validate, for the first time, a new assay to simultaneously measure levels of 6 forms of vitamin D along with two epimers. The assay was applied to multilevel certified reference material calibrators and 25 pooled human sera samples obtained from the Vitamin D External Quality Assessment Scheme (DEQAS) to demonstrate its efficiency. Results The assay is capable of simultaneously measuring 8 vitamin D analogues over the calibration ranges and LODs (in nmol/L) of: 1alpha25(OH)2D2 [0.015-1; 0.01], 1alpha25(OH)2D3 [0.1-100; 0.01], 25OHD3 [0.5-100, 0.025], 3-epi-25OHD3 [0.1-100, 0.05], 25OHD2 [0.5-100, 0.025], 3-epi-25OHD2 [0.1-100, 0.05], vitamin D3 [0.5-100, 0.05] and vitamin D2 [0.5-100, 0.05], using stanozolol-d3 as internal standard. Certified reference material calibrators and external quality control samples (DEQAS) were analysed to meet the standards outlined by National Institute of Standards and Technology (NIST). Validation steps included recovery and both precision and accuracy under inter- and intra-day variation limit of detection, and analysis of each analyte over a linear range. All validation parameters were in line with acceptable Food and Drug Administration (FDA) guidelines and the standards of the National Institute of Standards and Technology (NIST). All eight analogues were quantified with the 25OHD levels being commensurate with DEQAS data. Conclusions This report details the application of a new LC-MS/MS based assay for the efficient analysis of eight analogues of vitamin D over a range of samples, which is a significant advance over the existing methods. Simultaneous measure of 8 vitamin D analogues does not compromise the analytical capability of the assay to quantify the commonly used biomarker (25OHD) for vitamin D status. The results demonstrate the feasibility of applying the assay in research and clinical practice that i) excludes misleading measures owing to epimers and isobars and ii) is able to quantify the excluded component to facilitate further in vivo investigation into the roles of ubiquitous epimers

    Prevalence of vitamin D inadequacy in European postmenopausal women

    Full text link
    Objective: Inadequate vitamin D level is associated with secondary hyperparathyroidism and increased bone turnover and bone loss, which in turn increases fracture risk. The objective of this study is to assess the prevalence of inadequate serum vitamin D levels in postmenopausal European women. There are no clear international agreements on what constitutes a level of vitamin D inadequacy, but recent publications suggest that the circulating level of vitamin D should be over 80 nmol/L or at least between 50 and 80 nmol/L. Material and methods: Assessment of 25-hydroxyvitamin D [25(OH)D] was performed in 8532 European postmenopausal women with osteoporosis or osteopenia. European countries included France, Belgium, Denmark, Italy, Poland, Hungary, United Kingdom, Spain and Germany. Two cut-offs of 25(OH)D inadequacy were fixed < 80 nmol/L and < 50 nmol/L. Results: Mean (SD) age of the patients was 74.2 (7.1) years, body mass index was 25.7 (4.1)kg/m(2). Level of 25(OH)D was 61.0 (27.2) nmol/L. There was a highly significant difference of 25(OH)D level across European countries (p < 0.0001). The lowest level of 25(OH)D was found in France [51.5 (26.1) nmol/L] and the highest in Spain [85.2 (33.3) nmol/L]. In the whole study population, the prevalence of 25(OH)D inadequacy was 79.6% and 32.1 % when considering cut-offs of 80 and 50 nmol/L, respectively and when considering patients aged less than 65 years, the prevalence reached 86% (cut-off of 80 nmol/L) and 45% (cutoff of 50 nmol/L). Conclusion: This study indicates a high prevalence of vitamin D [25(OH)D] inadequacy in European postmenopausal women. The prevalence could be even higher in some particular countries. A greater awareness of the importance of vitamin D inadequacy is needed to address this public health problem
    corecore