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Hydroxyvitamin D (hydroxyvitamin + d)
Terms modified by Hydroxyvitamin D Selected AbstractsThe role of 25-Hydroxyvitamin D in normal and disturbed calcium metabolismEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 4 2003H. Reichel No abstract is available for this article. [source] Bone mineralization defects and vitamin D deficiency: Histomorphometric analysis of iliac crest bone biopsies and circulating 25-hydroxyvitamin D in 675,patientsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2010Matthias Priemel Abstract Parathyroid hormone (PTH) is only one measurable index of skeletal health, and we reasoned that a histomorphometric analysis of iliac crest biopsies would be another and even more direct approach to assess bone health and address the required minimum 25-Hydroxyvitamin D [25(OH)D] level. A cohort from the northern European population with its known high prevalence of vitamin D deficiency therefore would be ideal to answer the latter question. We examined 675 iliac crest biopsies from male and female individuals, excluding all patients who showed any signs of secondary bone diseases at autopsy. Structural histomorphometric parameters, including osteoid indices, were quantified using the Osteomeasure System according to ASBMR standards, and serum 25(OH)D levels were measured for all patients. Statistical analysis was performed by Student's t test. The histologic results demonstrate an unexpected high prevalence of mineralization defects, that is, a pathologic increase in osteoid. Indeed, 36.15% of the analyzed patients presented with an osteoid surface per bone surface (OS/BS) of more than 20%. Based on the most conservative threshold that defines osteomalacia at the histomorphometric level with a pathologic increase in osteoid volume per bone volume (OV/BV) greater than 2% manifest mineralization defects were present in 25.63% of the patients. The latter were found independent of bone volume per trabecular volume (BV/TV) throughout all ages and affected both sexes equally. While we could not establish a minimum 25(OH)D level that was inevitably associated with mineralization defects, we did not find pathologic accumulation of osteoid in any patient with circulating 25(OH)D above 75,nmol/L. Our data demonstrate that pathologic mineralization defects of bone occur in patients with a serum 25(OH)D below 75,nmol/L and strongly argue that in conjunction with a sufficient calcium intake, the dose of vitamin D supplementation should ensure that circulating levels of 25(OH)D reach this minimum threshold (75,nmol/L or 30,ng/mL) to maintain skeletal health. © 2010 American Society for Bone and Mineral Research [source] Baseline serum 25-hydroxyvitamin D concentrations in the Tromsų Study 1994,95 and risk of developing type 2 diabetes mellitus during 11 years of follow-upDIABETIC MEDICINE, Issue 10 2010G. Grimnes Diabet. Med. 27, 1107,1115 (2010) Abstract Aims, We wanted to test the hypothesis that low serum 25-hydroxyvitamin D (25(OH)D) concentrations are associated with increased risk of developing Type 2 diabetes mellitus (DM) in a population-based cohort during 11 years of follow-up. Methods, The analyses included 4157 non-smokers and 1962 smokers from the Tromsų Study 1994,95 without diabetes at baseline. Subsequent Type 2 DM was defined using a hospital journal-based end-point registry, completed through the year 2005. Participants were allocated into quartiles of serum 25(OH)D within each month to account for seasonal variation, and serum 25(OH)D values both as a continuous variable and in quartiles were used in Cox regression models. The analyses were stratified by smoking. Adjustments were made for age, sex, body mass index (BMI), physical activity and, in non-smokers, former smoking. Results, Type 2 DM was registered in 183 non-smoking and 64 smoking participants. Using the fourth (highest) quartile of serum 25(OH)D as the reference, non-smoking participants in the third, second and first quartiles had age- and sex-adjusted hazard ratios (95% confidence intervals) of incident Type 2 DM of 1.00 (0.62,1.61), 1.50 (0.97,2.31) and 1.89 (1.25,2.88), respectively, whereas the corresponding values for smokers were 1.79 (0.77,4.19), 2.33 (1.02,5.35) and 2.68 (1.18,6.08). Adjustment for BMI attenuated the hazard ratios, and they were no longer significant. Conclusions, Baseline serum 25(OH)D was inversely associated with subsequent Type 2 DM in a population-based 11 year follow-up study, but not after adjustment for BMI. Randomized trials are needed to define the possible role of serum 25(OH)D status, and thereby the role of supplementation, in the prevention of Type 2 DM. [source] Vitamin D Levels and Bone Turnover in Epilepsy Patients Taking Carbamazepine or OxcarbazepineEPILEPSIA, Issue 3 2006Scott Mintzer Summary:,Purpose: Evidence suggests that enzyme-inducing antiepileptic drugs (AEDs) may decrease serum 25-hydroxyvitamin D (25-OHD) levels and increase bone turnover. We sought to determine whether these are affected by treatment with carbamazepine (CBZ) or oxcarbazepine (OXC). Methods: We measured serum levels of 25-OHD, parathyroid hormone (PTH), osteocalcin (OCLN), bone alkaline phosphatase (BAP), and urinary N-telopeptides of type I collagen cross-links (NTX) in normal controls (n = 24) and in epilepsy patients taking CBZ (n = 21) or OXC (n = 24) in monotherapy. CBZ patients were subsequently switched overnight to OXC monotherapy, and after 6 weeks, the tests were repeated. Results: 25-OHD levels were lower in each drug-treated group (OXC, 19.4 ± 2.3 pg/ml; CBZ, 20.4 ± 2.4) than in the controls (27.5 ± 2.8) (ANOVA, p = 0.052). This difference was significant for the OXC group (p < 0.05). PTH, BAP, and NTX did not differ significantly among groups. OCLN levels were somewhat elevated in the OXC group (2.79 ± 0.47 ng/ml) and more clearly and significantly elevated in the CBZ group (3.63 ± 0.36) compared with controls (2.38 ± 0.41) (p = 0.053). Because the data were very similar between OXC and CBZ groups, they were combined to increase statistical power. The combined drug-treatment group had significantly higher BAP (p = 0.02) and lower 25-OHD (p = 0.015) than did controls. The latter remained significant even after accounting for the confounding effects of age on 25-OHD levels (p < 0.05). No significant differences were found after CBZ patients were switched to OXC. Conclusions: Epilepsy patients taking OXC or CBZ have significantly lower 25-OHD than do normal controls, with a pattern of changes in other bone biomarkers suggestive of secondary hyperparathyroidism. It may be prudent for patients taking CBZ or OXC to be prescribed 25-OHD replacement. [source] The prevalence of vitamin D abnormalities in South Asians with type 2 diabetes mellitus in the UKINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2010A. A. Tahrani Summary Background:, The high prevalence of both hypovitaminosis D and type 2 diabetes (T2DM) in the Asian community is well recognised, but the impact of diabetes on vitamin D status and vice versa, has not been well reported. Aims:, To determine the prevalence of hypovitaminosis D in Asian patients with T2DM and its impact on glycaemic control. Methods:, A cross-sectional study was conducted in a tertiary referral centre in the UK. Two hundred and ten Asian patients aged more than 40 years were included (170 with and 40 without T2DM). Each had a standard bone profile (serum calcium, phosphate and alkaline phosphatase), serum parathyroid hormone and 25-hydroxycholecalciferol. Results:, The prevalence of low serum 25-hydroxyvitamin D (< 50 nmol/l) was high in the group as a whole (> 80%) and more common in diabetics compared with controls (83% vs. 70%; p = 0.07). This was particularly so in men (82.5% vs. 57.9%; p = 0.02). HbA1c was higher in women with vitamin D deficiency (< 12.5 nmol/l) (8.11 ± 1.11% vs. 7.33 ± 1.32%, p = 0.046). In logistic regression analysis, T2DM was an independent predictor of hypovitaminosis D. In linear regression analysis, vitamin D deficiency was independently related to HbA1c in women with T2DM. Conclusions:, Hypovitaminosis D remains a major public health issue in the Asian population and is exaggerated in patients with T2DM. The fact that vitamin D deficient women had higher HbA1c levels raises the possibility that vitamin D replacement may improve glycaemic control. [source] Associations Between Vitamin D Status and Pain in Older Adults: The Invecchiare in Chianti StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2008Gregory E. Hicks PhD OBJECTIVES: To examine cross-sectional associations between vitamin D status and musculoskeletal pain and whether they differ by sex. DESIGN: Population-based study of persons living in the Chianti geographic area (Tuscany, Italy). SETTING: Community. PARTICIPANTS: Nine hundred fifty-eight persons (aged ,65) selected from city registries of Greve and Bagno a Ripoli. MEASUREMENTS: Pain was categorized as mild or no pain in the lower extremities and back; moderate to severe back pain, no lower extremity pain; moderate to severe lower extremity pain, no back pain; and moderate to severe lower extremity and back pain (dual region). Vitamin D was measured according to radioimmunoassay, and deficiency was defined as 25-hydroxyvitamin D (25(OH)D) less than 25 nmol/L. RESULTS: The mean age±standard deviation was 75.1±7.3 for women and 73.9±6.8 for men. Fifty-eight percent of women had at least moderate pain in some location, compared with 27% of men. After adjusting for potential confounders, vitamin D deficiency was not associated with lower extremity pain or dual-region pain, although it was associated with a significantly higher prevalence of at least moderate back pain without lower extremity pain in women (odds ratio=1.96, 95% confidence interval=1.01,3.59) but not in men. CONCLUSION: Lower concentrations of 25(OH)D are associated with significant back pain in older women but not men. Because vitamin D deficiency and chronic pain are fairly prevalent in older adults, these findings suggest it may be worthwhile to query older adults about their pain and screen older women with significant back pain for vitamin D deficiency. [source] Low Serum Vitamin D Does Not Predict New Disability or Loss of Muscle Strength in Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2002René Verreault MD OBJECTIVES: To determine whether serum levels of 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) predict accelerated decline in muscular strength or onset of new disability in mobility and upper extremity functioning over a 3-year follow-up. DESIGN: A community-based prospective cohort study. PARTICIPANTS: Six hundred twenty-eight moderately to severely disabled women aged 65 and older living in the community. MEASUREMENTS: Subjects were divided into three groups of baseline 25(OH)D serum levels (deficiency: <25 nmol/L; low normal: 25,52 nmol/L; high normal: ,53 nmol/L) and into tertiles of PTH levels. Objective performance measures (hip flexor, knee extensor, and grip strengths; walking speed; and time for repeated chair stands) and disability in activities involving mobility and upper extremity function were assessed at baseline and every 6 months for 3 years. Decline in performance measures and onset of new disability were compared between 25(OH)D and PTH groups using random effects models and proportional hazards models, respectively, while adjusting for age, race, education, body mass index, baseline performance, and chronic conditions. RESULTS: The annual rate of decline over 3 years in muscular strength, walking speed, and time to perform repeated chair stands was similar across 25(OH)D groups. We observed a nonsignificantly faster decline in proximal muscle strength and walking speed with increasing PTH levels. There was no association for either measure between serum levels and the risk of incident disability in activities relating to mobility and upper extremity function. CONCLUSION: This study does not support the hypothesis that vitamin D deficiency is associated with loss in muscular strength and decline in mobility and upper extremity functioning over time in older women who were moderately to severely disabled at baseline. [source] Bone mineralization defects and vitamin D deficiency: Histomorphometric analysis of iliac crest bone biopsies and circulating 25-hydroxyvitamin D in 675,patientsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2010Matthias Priemel Abstract Parathyroid hormone (PTH) is only one measurable index of skeletal health, and we reasoned that a histomorphometric analysis of iliac crest biopsies would be another and even more direct approach to assess bone health and address the required minimum 25-Hydroxyvitamin D [25(OH)D] level. A cohort from the northern European population with its known high prevalence of vitamin D deficiency therefore would be ideal to answer the latter question. We examined 675 iliac crest biopsies from male and female individuals, excluding all patients who showed any signs of secondary bone diseases at autopsy. Structural histomorphometric parameters, including osteoid indices, were quantified using the Osteomeasure System according to ASBMR standards, and serum 25(OH)D levels were measured for all patients. Statistical analysis was performed by Student's t test. The histologic results demonstrate an unexpected high prevalence of mineralization defects, that is, a pathologic increase in osteoid. Indeed, 36.15% of the analyzed patients presented with an osteoid surface per bone surface (OS/BS) of more than 20%. Based on the most conservative threshold that defines osteomalacia at the histomorphometric level with a pathologic increase in osteoid volume per bone volume (OV/BV) greater than 2% manifest mineralization defects were present in 25.63% of the patients. The latter were found independent of bone volume per trabecular volume (BV/TV) throughout all ages and affected both sexes equally. While we could not establish a minimum 25(OH)D level that was inevitably associated with mineralization defects, we did not find pathologic accumulation of osteoid in any patient with circulating 25(OH)D above 75,nmol/L. Our data demonstrate that pathologic mineralization defects of bone occur in patients with a serum 25(OH)D below 75,nmol/L and strongly argue that in conjunction with a sufficient calcium intake, the dose of vitamin D supplementation should ensure that circulating levels of 25(OH)D reach this minimum threshold (75,nmol/L or 30,ng/mL) to maintain skeletal health. © 2010 American Society for Bone and Mineral Research [source] Therapy of Osteoporosis With Calcium and Vitamin D,JOURNAL OF BONE AND MINERAL RESEARCH, Issue S2 2007Bess Dawson-Hughes MD Abstract Inadequate intakes of vitamin D and calcium lead to reduced calcium absorption, higher bone remodeling rates, and increased bone loss. Vitamin D insufficiency has also been linked to reduced muscle function and increased risk of falling. The mechanisms for the performance and muscle effects are not well understood. Administering vitamin D to those with inadequate vitamin D status has been shown to lower fracture rates in some trials but not in others. The purpose of this presentation is (1) to examine how calcium and vitamin D work in concert, (2) to consider key evidence that increasing vitamin D intake will affect risk of falls and fractures, and (3) to estimate the 25-hydroxyvitamin D [25(OH)D] level needed to achieve maximum fracture protection. [source] Vitamin D Receptor Expression in Human Muscle Tissue Decreases With Age,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2004HA Bischoff-Ferrari Abstract Intracellular 1,25-dihydroxyvitamin D receptor (VDR) is expressed in human skeletal muscle tissue. However, it is unknown whether VDR expression in vivo is related to age or vitamin D status, or whether VDR expression differs between skeletal muscle groups. Introduction: We investigated these factors and their relation to 1,25-dihydroxyvitamin D receptor (VDR) expression in freshly removed human muscle tissue. Materials and Methods: We investigated biopsy specimens of the gluteus medius taken at surgery from 20 female patients undergoing total hip arthroplasty (mean age, 71.6 ± 14.5; 72% > 65 years) and biopsy specimens of the transversospinalis muscle taken at surgery from 12 female patients with spinal operations (mean age, 55.2 ± 19.6; 28% > 65 years). The specimens were obtained by immunohistological staining of the VDR using a monoclonal rat antibody to the VDR (Clone no. 9A7). Quantitative VDR expression (number of VDR positive nuclei) was assessed by counting 500 nuclei per specimen and person. Serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were assessed at day of admission to surgery. Results: All muscle biopsy specimens stained positive for VDR. In the univariate analyses, increased age was associated with decreased VDR expression (r = 0.5: p = 0.004), whereas there were no significant correlations between VDR expression and 25-hydroxyvitamin D or 1,25-dihydroxyvitamin D levels. VDR expression did not differ between patients with hip and spinal surgery. In the multivariate analysis, older age was a significant predictor of decreased VDR expression after controlling biopsy location (gluteus medius or the transversospinalis muscle), and 25-hydroxyvitamin D levels (linear regression analysis: ,-estimate = ,2.56; p = 0.047). Conclusions: Intranuclear immunostaining of the VDR was present in muscle biopsy specimens of all orthopedic patients. Older age was significantly associated with decreased VDR expression, independent of biopsy location and serum 25-hydroxyvitamin D levels. [source] Genetic Contribution to Bone Metabolism, Calcium Excretion, and Vitamin D and Parathyroid Hormone RegulationJOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2001D. Hunter Abstract A classical twin study was performed to assess the relative contribution of genetic and environmental factors to bone metabolism, calcium homeostasis, and the hormones regulating them. It was examined further whether the genetic effect is menopause dependent. The subjects were 2136 adult twins (98.3% female): 384 monozygotic (MZ) and 684 dizygotic (DZ) twin pairs. The intraclass correlations were calculated, and maximum likelihood model fitting was used to estimate genetic and environmental variance components. The intraclass correlations for all of the variables assessed were higher in MZ twin pairs. The heritabilities (95% CIs) obtained from model fitting for hormones regulating bone metabolism and calcium homeostasis were parathyroid hormone (PTH), 60% (54,65%); 25-hydroxyvitamin D [25(OH)D]; 43% (28,57%), 1,25-hydroxyvitamin D [1,25(OH)], 65% (53,74%); and vitamin D binding protein 62% (56,66%). The heritabilities (95% CIs) for markers of bone formation also were assessed; bone-specific alkaline phosphatase (BSAP), 74% (67,80%), and osteocalcin, 29% (14,44%); marker of bone resorption deoxypyridinoline (DPD), 58% (52,64%); and measure of calcium homeostasis 24 h urine calcium, creatinine (Cr), 52% (41,61%). The magnitude of genetic influence differed with menopause for most variables. This study provides evidence for the importance of genetic factors in determining bone resorption and formation, calcium excretion, and the hormones regulating these processes. It shows for the first time a clear genetic effect on bone resorption in premenopausal women and the regulation of PTH, vitamin D metabolism, and calcium excretion. The genes controlling bone hormones and markers are likely to be useful therapeutic and diagnostic targets. [source] Hormonal and Biochemical Parameters and Osteoporotic Fractures in Elderly MenJOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2000Dr. Jacqueline R. Center Abstract Low testosterone has been associated with hip fracture in men in some studies. However, data on other hormonal parameters and fracture outcome in men is minimal. This study examined the association between free testosterone (free T) estradiol (E2), sex hormone-binding globulin (SHBG), 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), and fracture in 437 elderly community-dwelling men. Age, height, weight, quadriceps strength, femoral neck bone mineral density (FN BMD), and fracture data (1989,1997) also were obtained. Fractures were classified as major (hip, pelvis, proximal tibia, multiple rib, vertebral, and proximal humerus) or minor (remaining distal upper and lower limb fractures). Fifty-four subjects had a fracture (24 major and 30 minor). There was no association between minor fractures and any hormonal parameter. Risk of major fracture was increased 2-fold for each SD increase in age, decrease in weight and height, and increase in SHBG, and risk of major fracture was increased 3-fold for each SD decrease in quadriceps strength, FN BMD, and 25(OH)D (univariate logistic regression). Independent predictors of major fracture were FN BMD, 2.7 (1.5,4.7; odds ratio [OR]) and 95% confidence interval [CI]); 25(OH)D, 2.8 (1.5,5.3); and SHBG, 1.7 (1.2,2.4). An abnormal value for three factors resulted in a 30-fold increase in risk but only affected 2% of the population. It is not immediately apparent how 25(OH)D and SHBG, largely independently of BMD, may contribute to fracture risk. They may be markers for biological age or health status not measured by methods that are more traditional and as such may be useful in identifying those at high risk of fracture. [source] Premenopausal Smoking and Bone Density in 2015 Perimenopausal WomenJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2000Dr. A. P. Hermann Abstract The importance of cigarette smoking in relation to bone mass remains uncertain, especially in younger women. In a recent meta-analysis including 10 studies in premenopausal women no effect was seen in this age group. We used baseline data from a large national cohort study (Danish Osteoporosis Prevention Study [DOPS]) to study the cumulated effect of pre- and perimenopausal smoking on bone mineral density (BMD) measured shortly after the cessation of cyclic bleedings. Baseline observations on 2015 recently menopausal women were available. Eight hundred thirty-two women were current smokers and 285 were exsmokers. Significant negative associations of cigarette smoking coded as current, ex-, or never smoking were seen on bone mass in the lumbar spine (P = 0.012), femoral neck (P < 0.001), and total body (P < 0.001). Quantitatively, the differences between current smokers and never smokers were limited to 1.6, 2.9, and 1.9%, respectively. A statistical interaction was found between smoking and fat mass, indicating that women in the highest tertile of fat mass were unaffected by cigarette smoking. Serum vitamin D levels and osteocalcin were inversely related to the number of cigarettes smoked per day (r = 0.11 and P < 0.001; r = 0.17 and P = 0.04), respectively. Bone alkaline phosphatase (BALP) and urinary hydroxyproline (U-OHP) were unaffected by current smoking. The average cumulated effect of premenopausal smoking on bone is small but biologically significant. Reduced body mass in smokers explains part of the negative effect on the skeleton and a complex interaction between smoking and fat mass on the skeleton is indicated. Serum levels of 25-hydroxyvitamin D (25-OHD) and osteocalcin are lower in smokers, which may effect rate of bone loss. [source] Vitamin D and multiple sclerosisJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Anita Raghuwanshi Abstract Vitamin D is a principal regulator of calcium homeostasis. However, recent evidence has indicated that vitamin D can have numerous other physiological functions including inhibition of proliferation of a number of malignant cells including breast and prostate cancer cells and protection against certain immune mediated disorders including multiple sclerosis (MS). The geographic incidence of MS indicates an increase in MS with a decrease in sunlight exposure. Since vitamin D is produced in the skin by solar or UV irradiation and high serum levels of 25-hydroxyvitamin D (25(OH)D) have been reported to correlate with a reduced risk of MS, a protective role of vitamin D is suggested. Mechanisms whereby the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) may act to mediate this protective effect are reviewed. Due to its immunosuppressive actions, it has been suggested that 1,25(OH)2D3 may prevent the induction of MS. J. Cell. Biochem. 105: 338,343, 2008. © 2008 Wiley-Liss, Inc. [source] A high prevalence of hypovitaminosis D in Finnish medical in- and outpatientsJOURNAL OF INTERNAL MEDICINE, Issue 6 2001R. Kauppinen-Mäkelin Abstract.,Kauppinen-Mäkelin R, Tähtelä R, Löyttyniemi E, Kärkkäinen J, Välimäki MJ (Peijas Hospital, Vantaa; United Laboratories, Leiras Research, and Division of Endocrinology; Helsinki University Central Hospital, Helsinki, Finland). A high prevalence of hypovitaminosis D in Finnish medical in- and outpatients. J Intern Med 2001; 249: 559,563. Objective.,To study the prevalence of hypovitaminosis D [serum 25(OH)D , 37 nmol L,1)] in Finnish medical in- and outpatients in a cross-sectional study. Methods.,The subjects were 106 consecutive medical inpatients (57 females, 49 males with mean ages of 65 and 58 years) from the Peijas Hospital, Vantaa, Finland, and 99 ambulatory patients (48 females, 51 males with mean ages of 42 and 46 years) contacting a private outpatient centre in Helsinki, Finland. Serum 25(OH)D, vitamin D binding protein (DBP), free vitamin D index (FDI), intact PTH (iPTH), and albumin-corrected calcium were measured. Results.,Serum 25-hydroxyvitamin D [25(OH)D] was 37 nmol L,1 or less in 70% of female and in 61% of male inpatients and in 44% of female and in 37% of male outpatients. In the whole population, a statistically significant inverse association (P < 0.0001) was detected between iPTH and 25(OH)D levels; the iPTH concentration appeared to start increasing when 25(OH)D concentration was 50 nmol L,1 or less. The association remained the same (P < 0.0001) when FDI was used instead of 25(OH)D in the calculations. When the sexes were analysed separately, the statistically significant association was found only in females (P < 0.0001 for iPTH versus 25(OH)D; P < 0.0001 for iPTH versus FDI) but not in males. Conclusion.,Hypovitaminosis D is very common amongst Finnish in- and outpatients in both sexes, causing secondary hyperparathyroidism in females. More extensive studies are warranted to elucidate the vitamin D status of the Finnish population. [source] Dietary content may prevent secondary hyperparathyroidism in female rhesus monkeys (Macaca mulatta)JOURNAL OF MEDICAL PRIMATOLOGY, Issue 1 2000Julia E. Bruner Macaque laboratory chows provide relatively more calcium (Ca) and vitamin D (D) than human diets; this may influence skeletal aging. To evaluate this possibility, parameters of skeletal relevance in premenopausal and naturally postmenopausal rhesus monkeys were measured in a cross-sectional study. Serum osteocalcin (Oc) was elevated in the postmenopausal group (P<0.01), but levels of parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD) were not different. Subsequently, in premenopausal animals, dietary Ca and/or D intake was reduced to optimal human levels for 8 weeks prior to the evaluation of the skeletal parameters. Serum 25OHD concentration was reduced (P<0.01) and a trend (P=0.10) towards increased PTH was observed in both low D groups. In addition, serum alkaline phosphatase (ALP) levels were increased in the low Ca group (P<0.01). In conclusion, skeletal turnover, as measured by serum Oc, was increased in naturally postmenopausal rhesus monkeys in the absence of hyperparathyroidism. Dietary D reduction causes a decline in serum 25OHD and an upward trend in PTH. [source] Meta-analysis: longitudinal studies of serum vitamin D and colorectal cancer riskALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2009L. YIN Summary Background, In 1980, Garland hypothesized that lower levels of vitamin D resulting from much weaker UV-B radiation at higher latitudes may account for the striking geographical pattern of cancer mortality. Further research has been conducted over the past 20 years. Aim, To perform a systematic review and meta-analysis of longitudinal studies on the association between serum 25 hydroxyvitamin D (25(OH)D) and the risk of colorectal cancer (CRC). Methods, Relevant studies published until September 2008 were identified by systematically searching Ovid Medline, EMBASE, and ISI Web of Knowledge databases and by cross-referencing. Due to the heterogeneity of studies in categorizing serum vitamin D levels, all results were recalculated for an increase of serum 25(OH)D by 20 ng/mL. Summary odds ratios (ORs) were calculated using meta-analysis methods. Results, Overall, eight original articles reporting on the association between serum 25(OH) D and CRC risk were included. In meta-analyses, summary ORs (95% confidence intervals) for the incidence of CRC, colon cancer and rectal cancer associated with an increase of 25(OH)D by 20 ng/mL were 0.57 (0.43,0.76), 0.78 (0.54,1.13) and 0.41 (0.11,1.49). No indication for publication bias was found. Conclusions, Our results support suggestions that serum 25(OH)D is inversely related to CRC risk. [source] Effect of combined maternal and infant vitamin D supplementation on vitamin D status of exclusively breastfed infantsMATERNAL & CHILD NUTRITION, Issue 1 2009Hussein F. Saadi Abstract Severe vitamin D deficiency in mothers and their breastfed infants is a significant health problem in the Middle East. Supplementation of the breastfed infant alone with the recommended dose of vitamin D may be insufficient in high-risk population. We investigated the effect of combined maternal and infant vitamin D supplementation on vitamin D status of the breastfed infant. We examined also the effect of supplementation on vitamin D antirachitic activity of breast milk in a subset of mothers. Healthy breastfeeding mothers (n = 90) were randomly assigned to 2000 IU daily (group 1) or 60 000 IU monthly (group 2) of vitamin D2, and all their infants (n = 92) received 400 IU daily of vitamin D2 for 3 months. Most infants had vitamin D deficiency , 25-hydroxyvitamin D [25(OH)D] , 37.5 nmol L,1, at study entry. Serum 25(OH)D concentrations at 3 months increased significantly from baseline in infants of mothers in group 1 (13.9 ± 8.6 vs. 49.6 ± 18.5 nmol L,1, P < 0.0001) and group 2 (13.7 ± 12.1 vs. 44.6 ± 15.0 nmol L,1, P < 0.0001). Maternal and infant serum 25(OH)D concentrations correlated positively at baseline (r = 0.36, P = 0.01) and 3 months (r = 0.46, P = 0.002). Milk antirachitic activity increased from undetectable (<20 IU L,1) to a median of 50.9 IU L,1. In conclusion, combined maternal and infant vitamin D supplementation was associated with a threefold increase in infants' serum 25(OH)D concentrations and a 64% reduction in the prevalence of vitamin D deficiency without causing hypervitaminosis D. [source] Serum 25-hydroxyvitamin D and IgE , a significant but nonlinear relationshipALLERGY, Issue 4 2009E. Hyppönen Background:, Hormonal vitamin D system affects the determination of T-cell responses. It is unknown if there is an association between vitamin D status and allergic conditions. Our aim was to investigate differences in serum IgE concentrations by vitamin D status [measured by 25(OH)D] and by a genetic variation in a key vitamin D activation enzyme (CYP27B1) previously shown to be associated with type 1 diabetes. Methods:, 9377 participants in the 1958 British birth cohort completed a biomedical assessment at 45 years of age ; 7288 eligible participants had data on 25(OH)D and IgE, with 6429 having further information on CYP27B1 genotype (,1260C>A). Results:, There was a nonlinear association between 25(OH)D and IgE (P -value for curvature = 0.0001). Compared with the reference group with the lowest IgE concentrations [25(OH)D 100,125 nmol/l], IgE concentrations were 29% higher (95% CI 9,48%) for participants with the 25(OH)D <25 nmol/l, and 56% higher (95% CI 17,95%) for participants with 25(OH)D >135 nmol/l (adjusted for sex, month, smoking, alcohol consumption, time spent outside, geographical location, social class, PC/TV time, physical activity, body mass index and waist circumference). CYP27B1 genotype was associated with both 25(OH)D (difference for A vs. C allele: 1.88%, 95% CI 0.37,3.4%, P = 0.01) and IgE concentrations (,6.59%, ,11.6% to ,1.42%, P = 0.01). Conclusions:, These data suggest that there may be a threshold effect with both low and high 25(OH)D levels associated with elevated IgE concentrations. The same CYP27B1 allele that is protective of diabetes was associated with increased IgE concentrations. [source] Correcting poor vitamin D status: Do older adults need higher repletion doses of vitamin D3 than younger adults?MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 8 2010Susan J. Whiting Abstract We conducted an examination of recent studies to determine whether older adults (,65 years) need higher levels of supplementary vitamin D than young adults when attempting to replete vitamin D status in deficient subjects, i.e. those with levels of 25-hydroxyvitamin D less than 75,nmol/L. As data on repletion with vitamin D2 have recently been published, we restricted our discussion to the use of vitamin D3 from dietary supplements, prescriptions for large oral doses, and bolus dosing or injections. Most published dosing regimens failed to achieve 75,nmol/L in most all subjects, whether young adults (<65 years) or older adults (,65 years). Whether as daily or bolus oral supplementation, elderly subjects appeared to need more vitamin D3 compared with younger adults, however, baseline levels, endpoints, study duration, compliance, and other factors were different among studies. To ensure most subjects are replete in vitamin D, a daily dose of more than 50,,g (2000,IU) in younger and 125,,g (5000,IU) is required. Other strategies including bolus and loading doses are described. No study reported adverse effects of using oral intakes about the current upper level of 50,,g (2000,IU). [source] Vitamin D requirement and setting recommendation levels: long-term perspectivesNUTRITION REVIEWS, Issue 2008Leif Mosekilde Target intakes of vitamin D to prevent rickets and osteomalacia are difficult to estimate because of the dual sources of vitamin D with dermal production and absorption from the intestine. However, vitamin D deficiency is associated with other diseases, e.g., myopathy, falls, fractures, autoimmune disorders, cardiovascular diseases, and malignancies, which underlines the necessity of redefining recommendations. A plasma level of 25-hydroxyvitamin D (25OHD) <50 nmol/L increases the risk of secondary hyperparathyroidism, whereas levels between 75 and 100 nmol/L appear optimal for maintaining general health. In adults, a minimum dietary intake of 17.5,25 µg/day is necessary to achieve these levels. Perspectives of future research are outlined here. [source] Impact of vitamin D deficiency on the clinical presentation and prognosis of patients with newly diagnosed multiple myeloma,,AMERICAN JOURNAL OF HEMATOLOGY, Issue 7 2009Alvin C. Ng Vitamin D is a fundamental mediator of skeletal metabolism. It also has important nonskeletal actions. We hypothesized that vitamin D deficiency may play an important role in skeletal morbidity and clinical outcomes in MM. We studied 148 newly diagnosed MM patients from January 1, 2004 through December 31, 2008 who had a serum 25-hydroxyvitamin D [25(OH)D] obtained within 14 days of diagnosis. Subjects with vitamin D deficiency [25(OH)D level less than 50 nmol/L (20 ng/mL)] had higher mean values of serum C-reactive protein (CRP) (2.40 mg/L vs. 0.84 mg/L, P = 0.02) and creatinine (1.75 mg/dL vs. 1.24 mg/dL, P = 0.03) and lower serum albumin values (3.12 g/dL vs. 3.39 g/dL, P = 0.003) compared to subjects without vitamin D deficiency. The prevalence of vitamin D deficiency increased in parallel with International Staging System (ISS): 16% of subjects in Stage I, 20% in Stage II, and 37% in Stage III (P = 0.03) were vitamin D deficient. No differences were detected between the two groups in terms of skeletal morbidity. Association of vitamin D deficiency with higher serum CRP, serum creatinine and ISS stage at time of diagnosis suggests that vitamin D deficiency may portend poorer outcomes in subjects with MM. Am. J. Hematol. 2009. © 2009 Wiley-Liss, Inc. [source] The Vitamin D Status Among TibetansPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Gelsor Norsang UVB from the sun and intake from food are the only human sources of vitamin D. Tibet is a unique region for comparisons of these sources: (1) it lies at a low latitude and at a high altitude and has very large annual fluences of UVB; (2) the traditional Tibetan food is poor in vitamin D. Blood samples were taken from 63 persons of different age, with different occupations and staying at different places. UVB doses at these places were measured. The samples were analyzed by a standard radioimmune assay for determination of the serum concentration of 25 hydroxyvitamin D (25(OH)D). The main finding was that among nomads, there seems to be severe vitamin D deficiency (serum levels of 25(OH)D < 30 nm). We tentatively propose that the low level of 25(OH)D of nomads is related to their clothing and sun exposure habits. For persons of other occupations (students, teachers and farmers) the levels are higher, although a significant fraction of these persons also have lower levels than 75 nm, by many regarded as a limit for insufficiency related to a number of negative health conditions. The annual dose of vitamin D-generating UVB is about five times larger in Lhasa than in Oslo. Despite this, the average vitamin D status seems to be similar, except in the case of nomads. This phenomenon is certainly related to food habits. In conclusion, the 25(OH)D status among nomads in Tibet appears to be alarmingly low. However, for people of other occupations the status is more normal. [source] Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 4 2010Brian L. Diffey Background/purpose: The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. Methods: The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. Results: It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health. Conclusions: Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status. [source] Vitamin D production in psoriasis patients increases less with narrowband than with broadband ultraviolet B phototherapyPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 3 2009Amra Osmancevic Background: Phototherapy of psoriasis is an effective treatment. In addition to standard broadband ultraviolet radiation B (UVB), (280,320 nm), narrowband phototherapy (NBUVB) (monochromatic UV between 311 and 312 nm) has become an important treatment for psoriasis. The same wavelength range of UVB (290,315 nm) induces synthesis of vitamin D. The aim was to compare the effect of broadband with NBUVB therapy on vitamin D synthesis in patients with psoriasis. Methods: Sixty-eight Caucasian patients (17 women and 51 men) mean age 54.1 ± 16.0 years, with active plaque psoriasis, were treated with broadband UVB (n=26) or NBUVB (n=42) two to three times/week for 8,12 weeks. The serum concentrations of 25-hydroxyvitamin D (25(OH)D3), 1,25-dihydroxyvitamin D (1,25(OH)2D3), intact parathyroid hormone (PTH), calcium and creatinine were measured before the first exposure and after the last dose of radiation. Results: In broadband UVB treated patients, 25(OH)D3 increased from 37.9 ± 16.9 to 69.4 ± 19.7 ng/ml (P<0.0001) and in patients treated with NBUVB from 34.8 ± 11.9 to 55.3 ± 17.6 ng/ml (P<0.0001) and P=0.008 between the treatment groups. PTH decreased on broadband UVB (P<0.05). The serum concentrations of 1,25(OH)2D3, calcium or creatinine remained unaltered. Conclusion: Serum 25(OH)D3 in psoriasis patients increased less with NBUVB than with broadband UVB phototherapy. Psoriasis improved on both regimens. [source] The effect of ultraviolet B-induced vitamin D levels on host resistance to Mycobacterium tuberculosis: a pilot study in immigrant Asian adults living in the United KingdomPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2 2008Paul Devakar Yesudian Summary Asian immigrants to the United Kingdom demonstrate much higher tuberculosis rates than the indigenous population. This is postulated to be because of their low vitamin D levels, consequent upon a combination of diet and their reduced ultraviolet (UV) exposure in the United Kingdom, because vitamin D enhances antimycobacterial activity in in vitro systems. The aim of this study was to examine the relationship between UVB exposure, vitamin D levels and tuberculo-immunity in Asian immigrants in the United Kingdom. Suberythemal UVB treatments were given to eight subjects on 3 consecutive days, using broadband UVB fluorescent lamps. Blood was sampled for 25-hydroxyvitamin D (25-OH D) and whole blood functional assays were performed for antimycobacterial immunity. The mean 25-OH D level increased from a baseline of 11.23 ng/ml (95% CI 6.7,20.39) to 20.39 ng/ml (95% CI 16.6,20) following UVB treatment, P<0.01. However, no significant change in antimycobacterial immunity occurred following UVB exposure. This pilot study in Asian subjects with good baseline tuberculo-immunity has not supported a role for UVB-induced 25-OH D in the immune response to Mycobacterium tuberculosis. [source] Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer riskTHE PROSTATE, Issue 9 2007Bahar Mikhak Abstract BACKGROUND The vitamin D receptor (VDR) is required for actions of vitamin D. The binding of 1,25-dihydroxyvitamin D to the VDR on prostatic epithelial cells prompts the regulation of cancer-related genes. METHODS We conducted a nested case-control study in the Health Professionals Follow-up Study to investigate the role of the VDR Cdx2, Fok1, and Bsm1 gene polymorphisms and associated haplotypes and their interaction with plasma vitamin D metabolites in relation to prostate cancer (PC) risk. RESULTS No association was found between these SNPs or their associated haplotypes and all PC subtypes except that haplotype 2 (A-f-b) with Cdx2 A, Fok1 f, and Bsm1 b alleles and haplotype 3 (A-F-B) with Cdx2 A, Fok1 F and Bsm1 B alleles compared to the most common haplotype (A-F-b), were associated with reduced risk of aggressive PC (high stage or Gleason sum ,7; P,=,0.02), both with two alleles suspected of being low risk. Carriers of the variant Cdx2 A allele who were deficient in plasma 25-hydroxyvitamin D (,15 ng/ml) compared to non-carriers with normal 25-hydroxyvitamin D, had a lower risk of total and poorly differentiated PCs (Gleason sum ,7) (P for interaction,=,0.02 and 0.04, respectively). Plasma 1,25-dihydroxyvitamin D deficiency (,26 pg/ml) was associated with a threefold risk of poorly differentiated PC (P for interaction,=,0.01) when comparing carriers of the Cdx2 A allele to non-carriers with normal 1,25-dihydroxyvitamin D. CONCLUSION In this population of men, none of the VDR polymorphisms studied was associated with susceptibility to PC. Prostate 67: 911,923, 2007. © 2007 Wiley-Liss, Inc. [source] Higher 25-hydroxyvitamin D is associated with lower relapse risk in multiple sclerosis,ANNALS OF NEUROLOGY, Issue 2 2010Steve Simpson Jr. MPH Objective A protective association between higher vitamin D levels and the onset of multiple sclerosis (MS) has been demonstrated; however, its role in modulating MS clinical course has been little studied. We investigated whether higher levels of serum 25-hydroxyvitamin D (25-OH-D) were associated with a lower risk of relapses in people with MS. Methods We conducted a prospective cohort study of 145 participants with relapsing-remitting MS from 2002 to 2005. Serum 25-OH-D levels were measured biannually, and the hazard of relapse was assessed using survival analysis. Results There was an inverse linear relationship between 25-OH-D levels and the hazard of relapse over the subsequent 6 months, with hazard ratio (HR) 0.91 (95% confidence interval [CI]: 0.85,0.97) per 10nmol/l increase in 25-OH-D level (p = 0.006). When variation due to timing of blood collection was removed by estimating 25-OH-D at the start of each season, this association persisted, with HR 0.90 (95% CI, 0.83,0.98) per 10nmol/l increase (p = 0.016). Taking into account the biological half-life of 25-OH-D, we estimated 25-OH-D at monthly intervals, resulting in a slightly enhanced association, with HR 0.88 (95% CI, 0.82,0.95) per 10nmol/l increase (p = 0.001). Adjusting for potential confounders did not alter these findings. Interpretation In this prospective population-based cohort study, in a cohort largely on immunomodulatory therapy, higher 25-OH-D levels were associated with a reduced hazard of relapse. This occurred in a dose-dependent linear fashion, with each 10nmol/l increase in 25-OH-D resulting in up to a 12% reduction in risk of relapse. Clinically, raising 25-OH-D levels by 50nmol/l could halve the hazard of a relapse. ANN NEUROL 2010;68:193,203 [source] Association of 25-hydroxyvitamin D with prevalent osteoarthritis of the hip in elderly men: The osteoporotic fractures in men studyARTHRITIS & RHEUMATISM, Issue 2 2010R. K. Chaganti Objective To examine the cross-sectional association of serum levels of 25-hydroxyvitamin D, or 25(OH)D, with prevalent radiographic hip osteoarthritis (OA) in elderly men. Methods In a cohort of 1,104 elderly men from the Osteoporotic Fractures in Men Study, 25(OH)D serum levels were determined by mass spectrometry, followed by pelvic radiographs ,4.6 years later. Categories of vitamin D levels were defined as follows: deficiency as ,15 ng/ml, insufficiency as 15.1,30 ng/ml, and sufficiency as >30 ng/ml. Radiographs were assessed for severity of hip OA using a summary grade of 0,4 for individual features of hip OA. Logistic regression was used to assess associations of serum 25(OH)D levels with prevalent radiographic hip OA; covariates included age, clinic site, season at the time of blood withdrawal, self-reported hip pain for >30 days, timed 6-meter walk, presence of at least 1 coexisting condition, and self-rated health status. Results Men with radiographic hip OA had a slower 6-meter walking time (P < 0.0001), reported more hip pain (P = 0.0001), had a lower vitamin D level (P = 0.0002), and had a higher prevalence of vitamin D insufficiency (P = 0.002) and vitamin D deficiency (P = 0.012) compared with controls. Higher 25(OH)D levels were associated with a lower prevalence of radiographic hip OA (odds ratio [OR] 1.39 per 1 SD decrease in 25[OH]D, 95% confidence interval [95% CI] 1.11,1.74) after adjusting for age, season, and clinic site. Men with vitamin D insufficiency had an increased likelihood of prevalent radiographic hip OA (OR 2.19, 95% CI 1.21,3.97) compared with men with sufficient levels of 25(OH)D, and in men with vitamin D deficiency, there was a tendency toward an increased likelihood of radiographic hip OA (OR 1.99, 95% CI 0.83,4.74). Conclusion Men with vitamin D deficiencies are twice as likely to have prevalent radiographic hip OA, and therefore vitamin D therapy to augment skeletal health in the elderly is warranted. [source] Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: The Tasmanian older adult cohort studyARTHRITIS & RHEUMATISM, Issue 5 2009Changhai Ding Objective To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross-sectionally and longitudinally in older adults. Methods A total of 880 randomly selected subjects (mean age 61 years [range 51,79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25-hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1-weighted fat-suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed. Results The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13,119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D level <50 nmoles/liter was associated with increased medial tibiofemoral joint space narrowing (all P < 0.05). Longitudinally, baseline serum 25(OH)D level predicted change in both medial and lateral tibial cartilage volume (, = +0.04% per annum per nmole/liter for both; P < 0.05), and change in serum 25(OH)D level was positively associated with change in medial tibial cartilage volume. These associations were consistent in subjects with radiographic OA and knee pain and/or in women, but not in men or in subjects without radiographic OA or knee pain. Conclusion Sunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA. [source] | |||||||||||||||||||||||||