Search

Objective: To provide recommendations based on evidence on the management of vitaminD deficiency in the general population., Participants: Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology., Methods: Recommendations were formulated using the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed) using the term VitaminD and the name of each issue. Papers in English and Spanish with publication date before 17 March 2016 were included. Recommendations were jointly discussed by the Working Group., Conclusions: This document summarizes the data about vitaminD deficiency in terms of prevalence, etiology, screening indications, adequate levels and effects of supplementation on bone and non-skeletal health outcomes., (Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.)

Despite the discussion on the optimal threshold of 25-hydroxyvitamin D serum level continues, there is now consensus on the fact that post-menopausal and elderly populations have inadequate Vitamin D serum levels worldwide. The adjustment of these levels is necessary to improve both bone and general health, as it is to optimize bone response to antiresortive treatments. It is recommended, as endorsed by international clinical guides, to use Vitamin D 3 , the physiological form of Vitamin D, in a dose range between 600-2000IU. It should be administered on a daily basis or on its weekly or monthly equivalents. In Spain, the use of calcidiol (25(OH)D 3 ) at the same dose than Vitamin D 3 is the most extended prescription, notwithstanding the available evidence stating that they are not equipotent. This may lead to over-dosage. In order to provide evidence on this circumstance, a convenience study was performed. Four groups of ten post-menopausal osteoporotic women each (average age 67), deficient in Vitamin D ((25(OH)D 37.5±10 nmol/L)) were enrolled. Each group followed a different treatment regimen: (G1) vitamin D 3 20μg/day [800IU/day]; (G2) 25 (OH)D 3 20μg/day; (G3) 25(OH)D 3 266μg/week and (G4) 25(OH)D 3 0.266mg every two weeks. 25(OH)D levels were measured for each group at 0, 6 and 12 months, with the following results: G1 (40.5±4.7;80.0±2; 86.2±23.7), G2 (37,2±4.2; 161±21.7;188.0±24.0), G3 (38±3.7;213.5±80.0; 233.0±81.2), G4 (39.5±4;164.5±41,7;210.5±22.2). These data reveal that both metabolites are not equipotent. Calcidiol is faster and 3-6 times more potent to obtain serum levels of 25(OH)D in the medium to long term. This circumstance must be assessed and included in the therapeutic prescription guides for Osteoporosis, since it should be of concern when planning and prescribing treatments to normalize serum levels of 25(OH)D 3 and avoid potential adverse impacts., (Copyright © 2016. Published by Elsevier Ltd.)

Vitamin D is obtained mainly from ultraviolet irradiation of 7-dehydrocholesterol in the skin to form cholecalciferol (vitamin D3), and minimally from diet, unless vitamin D fortified food is taken, mainly enriched milk. In some countries, vitamin D is added to diet as ergocalciferol (vitamin D2). In the liver, vitamin D3 is hydroxylated to form 25-hydroxyvitamin D3 (marker of body nutritional status of vitamin D). Subsequently, in the kidney, 25OHD3 is hydroxylated to form 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). By VDR stimulation, (1,25)OH)2D3 controls calcium homeostasis and bone health and, what is more, many other cells and tissues including skin, muscle, cardiovascular and immune systems as well as glucose homeostasis. Thus, about 3% of the human genome is regulated by this hormone. Association and recent intervention studies describe beneficial effects on bone, cardiovascular disease, hypertension, diabetes mellitus type 2,colorectal cancer, breast cancer, multiple sclerosis, immune function inflammation etc. A minimum target for public health should be to achieve serum 25OHD levels above 20 ng/ml to ensure optimum status for bone health. However, levels above 30 ng/ml should be reached to achieve other health goals. Paradoxically, inadequacy (or even deficiency) in vitamin D levels is highly prevalent in children and youth in Spain. This deficit persists in adults, as well as in postmenopausal women (osteoporotic or not) and the elderly (especially amongst those institutionalized). Seasonal variation barely normalizes serum 25OHD levels after summer-autumn. Treated postmenopausal osteoporotic women also show high prevalence of inadequate levels of vitamin D, a major contributor to antiresortive treatments failure. A normalization of serum vitamin D enables diet to provide the calcium necessary to achieve a good bone health and an adequate response to antiresortive drugs. Given the difficulty to get adequate levels of vitamin D by UV irradiation and diet, a proper supplementation of milk with vitamin D is an attractive chance and a challenge for Public Health of Spain and the European Union. It has provided excellent results in the US, Canada, Northern Europe Countries, etc., (Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.)

A method for quantitative analysis of vitamin D (both D2 and D3) and its main metabolites - monohydroxylated vitamin D (25-hydroxyvitamin D2 and 25-hydroxyvitamin D3) and dihydroxylated metabolites (1,25-dihydroxyvitamin D2, 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3) in human serum is here reported. The method is based on direct analysis of serum by an automated platform involving on-line coupling of a solid-phase extraction workstation to a liquid chromatograph-tandem mass spectrometer. Detection of the seven analytes was carried out by the selected reaction monitoring (SRM) mode, and quantitative analysis was supported on the use of stable isotopic labeled internal standards (SIL-ISs). The detection limits were between 0.3-75pg/mL for the target compounds, while precision (expressed as relative standard deviation) was below 13.0% for between-day variability. The method was externally validated according to the vitamin D External Quality Assurance Scheme (DEQAS) through the analysis of ten serum samples provided by this organism. The analytical features of the method support its applicability in nutritional and clinical studies targeted at elucidating the role of vitamin D metabolism., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Unlabelled: An observational cross-sectional study was conducted to assess calcium intake and vitamin D status by measurement of 25-hydroxyvitamin D (25(OH)D), in postmenopausal osteoporotic women (PMOW) treated and untreated for osteoporosis. To assess the influence of sunlight exposure on vitamin D status, the study group was categorized on the basis of sunlight exposure (above or below 2500 sunlight h/year). A group of 336 PMOW older than 65 years was identified (190 [56.5%] treated and 146 [43.5%] untreated for osteoporosis). The demographic and clinical data of the PMO women included history of prior fractures, pharmacological treatments and dietary calcium intake. BMD was measured by DEXA and 25(OH)D was determined by an HPLC method., Results: vitamin D serum levels were lower in the untreated group as compared with the treated group (58±27 vs. 67±27nmol/l; p=0.006). Prevalence of vitamin D deficiency (cut-off point set at <50nmol/l) was higher in the non-treated group (43.8% vs. 29.5%; p=0.009). Nearly all PMOW, whether treated or not for osteoporosis had a total calcium intake of less than 1200mg. Sunlight exposure did not influence the vitamin D status., Conclusions: vitamin D deficiency and an insufficient calcium intake are highly prevalent in both treated and untreated Spanish PMOW older than 65 years. This can be related to low therapeutic adherence and/or insufficient prescription. Therefore physician's and patient's knowledge regarding the optimization of vitamin D status and calcium intake should be improved and implemented. This article is part of a Special Issue entitled 'Vitamin D workshop'., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Unlabelled: Bone mineral density (BMD) is a main determinant of osteoporotic fractures. A cross-sectional study was conducted in 229 young, healthy postmenopausal women (PMW) to evaluate the contribution of the vitamin D endocrine system and other clinical, biochemical and genetic parameters. Clinical risk factors for osteoporosis were obtained by a questionnaire. Serum concentrations of 25OHD, 1,25(OH)2D, PTH, and bone turnover markers were measured. The BsmI, FokI and Cdx-2 polymorphisms of the vitamin D receptor (VDR) gene were determined. DXA and the WHO criteria were applied for the diagnosis of osteoporosis. Univariate logistic and multivariate logistic regression analyses were carried out., Results: The prevalence of vitamin D deficiency (<50nmol/l) was 50%. Age increased osteoporosis risk; whereas body mass index (BMI), number of reproductive years, 25OHD level and the Cdx-2 polymorphism in the VDR gene (when allele A is present) were found to be protective. Therefore, both serum 25OHD and VDR polymorphism should be taken into account in the evaluation and implementation of therapeutic strategies concerning PMW, especially as the prevalence of vitamin D deficiency is still alarmingly high even at Southern latitudes. This article is part of a Special Issue entitled 'Vitamin D Workshop'., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The combination of calcium with vitamin D (vitamin D(3) [colecalciferol]) forms the basis of preventive and therapeutic regimens for osteoporosis. A number of studies have suggested that the combination of calcium and vitamin D is effective when administered at respective dosages of at least 1200 mg and 800 IU per day, although efficacy is, as expected, affected by patient compliance. Overall, treatment with this combination appears to be effective in reducing the incidence of non-vertebral and hip fractures. Also, in all drug studies (of antiresorptive and anabolic agents and strontium ranelate) that demonstrated a reduction in risk of osteoporotic fractures, patients also took calcium and vitamin D supplements. An important finding in this regard is that vitamin D levels have been demonstrated to be inadequate in more than half of women treated for osteoporosis in the US and Europe. The capacity of the small intestine to absorb calcium salts depends on the solubility and ionization of the salts. These properties vary for different salts, with fasting calcium citrate absorption being greater than that of calcium lactogluconate and calcium carbonate. Calcium citrate formulations taken between meals may help to prevent abdominal distension and flatulence, as well as minimize the risk of renal calculus formation, thus helping to optimize patient compliance. Therefore, calcium citrate combined with vitamin D is the combination of choice for the prevention or treatment of osteoporosis.

Vitamin D deficiency is recognized as one of the most common chronic medical conditions in the world. Vitamin deficiency has been associated with increased mortality. The aim of the study here presented was to evaluate the vitamin D endocrine system (VDES) status in healthy blood donors and critically ill patients baseline and in response to treatment during a week with two doses of 1.5 mg of 25-hydroxyvitamin D3 and 2 microg calcitriol (1,25(OH)2D3) IV on alternate days, by monitoring levels in serum of major vitamin D metabolites in critically ill patients. Group 1: healthy blood donors (control group) (n=92), and group 2: critically ill subjects from an intensive care unit (ICU) (n=33). Critically ill patients were divided into three groups: group A (n=12) is the control group; group B (n=11), administration PO 1,5 mg of 25(OH)D3, in days 0 and 4 of treatment; and group C (n=11), administration IV of 2 microg 1,25(OH)2D3 on alternate days. Baseline serum levels of vitamin D2 and 25(OH)D2 were not detected. Vitamin D3 (9.8 vs 26.0 nM) (p<0.05), 25(OH)D3 (13.3 vs 52.3 nM) (p<0.001), and 1,25(OH)2D3 (53.8 vs 120.5 pM) (p<0.01) serum levels were significantly lower in critically ill subjects than in healthy donors. After treatment in group B: 25OHD3 increased to 46.0+/-16.5 ng/ml (p<0.0001) (22.2%<75 nM, 11.1% <50 nM). 1,25(OH)2D3 increased to 121.8+/-61.8 pM<0.01 whereas were slightly decreased in the other groups during the study. 24,25(OH)2D3 serum levels were increased in patients treated with calcitriol 8.5+/-5.3 vs 24.8+/-16.3 nM (p<0.05) while the levels kept stable in group A patients. In summary, critically ill patients have a severe vitamin D deficiency, which can be easily corrected by administration of high doses of 25OHD (PO). The VDES functional deficiency could be probably also corrected through administration of calcitriol (IV). Both treatments could produce an improvement in the general health and probably a reduction in overall mortality risk of the critically ill patients., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Background: Fat soluble vitamins and vitamin D metabolites are key compounds in bone metabolism. Unfortunately, variability among 25(OH)D assays limits clinician ability to monitor vitamin D status, supplementation, and toxicity., Method: 0.5 ml serum was mixed with 0.5 ml 60% acetonitrile 150 mM sodium dodecyl sulfate, vortexed for 30 s and injected into an automatic solid-phase extraction (SPE) system for cleanup-preconcentration, then on-line transferred to a reversed-phase analytical column by a 15% methanol-acetonitrile mobile phase at 1.0 ml/min for individual separation of the target analytes. Ultraviolet detection was performed at 265 nm, 325 nm and 292 for vitamin D metabolites, vitamin A and alpha- and delta-tocopherols, respectively., Results: Detection limits were between 0.0015 and 0.26 microg/ml for the target compounds, the precision (expressed as relative standard deviation) between 0.83 and 3.6% for repeatability and between 1.8 and 4.62% for within laboratory reproducibility. Recoveries between 97-100.2% and 95-99% were obtained for low and high concentrations of the target analytes in serum. The total analysis time was 20 min., Conclusions: The on-line coupling of SPE-HPLC endows the proposed method with reliability, robustness, and user unattendance, making it a useful tool for high-throughput analysis in clinical and research laboratories.