Relation between vitamin D insufficiency, bone density, and bone metabolism in healthy postmenopausal women.

Although only few postmenopausal women exhibit biochemical signs of hypovitaminosis D, vitamin D insufficiency has been shown to have adverse effects on bone metabolism and could be an important risk factor for osteoporosis and fracture. We determined serum levels of 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), bone turnover markers, dietary calcium intake, and bone mineral density (BMD; measured by dual X-ray absorptiometry) in 161 consecutive ambulatory women, healthy except for osteoporosis, referred to a bone metabolic unit. The prevalence of vitamin D insufficiency [25(OH)D < or = 15 ng/ml] was 39.1%. 25(OH)D was lower in the osteoporotic subjects (15.7 +/- 5.3 ng/ml vs. 21.8 +/- 9.7 ng/ml; p < 0.001). After controlling for all other variables, lumbar spine (LS) BMD was found to be significantly associated with 25(OH)D, body mass index (BMI), and years after menopause (YSM) (R2 = 0.253; p < 0.001). For femoral neck (FN), significant independent predictors of BMD were YSM, BMI, iPTH, and 25(OH)D (R2 = 0.368; p < 0.001). The probability of meeting osteoporosis densitometric criteria was higher in the vitamin D insufficiency group (odds ratio [OR], 4.17, 1.83-9.48) after adjusting by YSM, BMI, iPTH, and dietary calcium intake. Our study shows that vitamin D insufficiency in an otherwise healthy postmenopausal population is a common risk factor for osteoporosis associated with increased bone remodeling and low bone mass.     

老年患者25( OH) D、PTH与骨折的相关分析

目的了解骨科老年患者25-羟基维生素D(25(OH)D)、甲状旁腺激素(PTH)水平及与骨折的相关性。方法2011.8~2014.12我院骨科老年患者428名,72.47±6.19岁,其中骨折192名。测定血清25(OH)D和PTH,腰椎(L1-4)、全髋、股骨颈骨密度。比较骨折与非骨折组25(OH)D,PTH及骨密度的差异;分析25(OH)D、PTH各组骨折和骨密度的差异;分析25(OH)D和PTH、骨密度的相关性;用相对工作特征曲线(relative operating characteristic,ROC curve)分析25(OH)D对骨折的预测价值。结果骨折组与非骨折组相比,25(OH)D水平及全髋和股骨颈骨密度偏低。不同25(OH)D水平组骨折发生的差异具有统计学意义,维生素D严重缺乏组、缺乏组骨折发生率较高。维生素D严重缺乏组、缺乏组、不足组的骨密度偏低,PTH增高组骨密度也偏低。25(OH)D与PTH、腰椎(L1-4)、全髋、股骨颈BMD存在相关性。ROC曲线下面积为0.529,不能以25(OH)D的水平预测骨折。结论骨科老年患者存在严重的维生素D缺乏,维生素D缺乏者骨折发生率明显增高,对其应从补充维生素D、预防跌倒、提高骨质量等多方面进行综合干预。     

Vitamin D status in relation to obesity, bone mineral density, bone turnover markers and vitamin D receptor genotypes in healthy Saudi pre- and postmenopausal women

Summary

The various factors that may contribute to vitamin D deficiency or insufficiency were examined among healthy Saudi pre- and postmenopausal women. Vitamin D deficiency was highly prevalent among studied Saudi women with obesity, poor sunlight exposure, poor dietary vitamin D supplementation and age as the main risk factors.

Introduction

The various factors that may contribute to vitamin D deficiency or insufficiency in relation to bone health among Saudi women are not known. The main objectives of the present study were to determine the factors influencing vitamin D status in relation to serum 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (PTH), bone turnover markers (BTMs), bone mineral density (BMD), and vitamin D receptor genotype (VDR) in healthy Saudi pre- and postmenopausal women.

Methods

A total number of 1,172 healthy Saudi women living in the Jeddah area were randomly selected and studied. Anthropometric parameters, socioeconomic status, sun exposure index together with serum levels of 25(OH)D, calcitriol, intact PTH, Ca, PO4, Mg, creatinine, albumin, and biochemical BTMs were measured. BMD was measured by a dual energy X-ray absorptiometry and VDR genotypes were also determined.

Results

About 80.0% of Saudi women studied exhibited vitamin D deficiency (serum 25(OH)D?<?50.0?nmol/L) with only 11.8% of all women were considered with adequate vitamin D status (serum 25(OH)D?>?75?nmol/L). Secondary hyperparathyroidism was evident in 18.5% and 24.6% in pre- and postmenopausal women with 25(OH)D?<?50?nmol/L. Serum 25(OH)D was lower (P?<?0.001) and intact PTH higher (P?<?0.001) in the upper quintiles of body mass index (BMI) and waist-to-hip ratio (WHR). Multiple linear regression analysis showed that BMI, sun exposure index, poor dietary vitamin D supplementation, WHR, and age were independent positive predictors of serum 25(OH)D values.

Conclusions

Vitamin D deficiency is highly prevalent among healthy Saudi pre-and postmenopausal women and largely attributed to obesity, poor exposure to sunlight, poor dietary vitamin D supplementation, and age.     

Vitamin D, parathyroid hormone levels and bone mineral density in community-dwelling older women: The Rancho Bernardo Study

Vitamin D (25(OH)D) increases the efficiency of intestinal calcium absorption. Low levels of serum calcium stimulate the secretion of parathyroid hormone (PTH), which maintains serum calcium levels at the expense of increased bone turnover, bone loss and increased risk of fractures. We studied the association between 25(OH)D and PTH levels, and their associations with bone mineral density (BMD), bone loss, and prevalence of hip fractures in 615 community-dwelling postmenopausal aged 50–97 years. Mean level of 25(OH)D and PTH were 102.0 nmol/l±35.0 nmol/l and 49.4 ng/l±23.2 nmol/l, respectively; 49% of women were current hormone therapy users. The overall prevalence of vitamin D insufficiency (25(OH)D<50 nmol/l) was 2%, and prevalence of high PTH levels (>65 ng/l) was 17.4%. In multiple linear regression analyses hip BMD was negatively and independently associated with PTH levels ( p =0.04), and positively and independently associated with 25(OH)D levels ( p =0.03). There were only 23 women (3.7%) who experienced a hip fracture. In age-adjusted analyses there were no significant differences of 25(OH)D and PTH levels by hip fracture status. Across the entire range of values, the overall correlation between 25(OH)D and PTH was moderate ( r =–0.20). However, after the threshold vitamin D level of 120 nmol/l, all PTH values were below 65 ng/l. Further studies are necessary to identify the optimal vitamin D levels necessary to prevent secondary hyperparathyroidism.     

北京地区中老年人FRAX骨折风险评估与BMD、骨代谢相关生化指标间的相关回归研究

目的探讨北京南郊地区中老年人FRAX评估未来10年全身骨折风险PMOF、骨密度BMD、骨代谢相关指标指标25(OH)D3、PTH、N-MID等在年龄、性别、体质指数之间的差异及变化趋势,研究PMOF、骨密度与各骨代谢相关生化指标之间的相关性。方法收集接受DXA桡骨远端骨密度(BMD)检查的体检人群1133例,代入FRAX骨折风险评估工具计算全身主要部位骨折概率(PMOF),收集相应骨代谢生化指标:25-羟维生素D3[25(OH)D_3],血清骨钙素N端中分子片段(N-MID),甲状旁腺素(PTH)、血钙(Ca)、血磷(P)、血清碱性磷酸酶(ALP)等。分析比较各指标随年龄的变化趋势,比较各年龄组各指标性别间差异;分析比较不同性别、各年龄组中各指标在不同体质指数之间的差异及其变化趋势;采用多元逐步回归法分别分析未来10年骨折风险概率(PMOF)、BMD与各因素、各生化指标之间的相关回归关系。结果非优势手臂桡骨远端1/3处骨密度BMD随年龄增长而降低,各年龄组男性BMD值均大于女性,PMOF随年龄增长而增加,各年龄组男性PMOF均小于女性,差异有统计学意义(P0.05);各年龄组25(OH)D_3水平男性均大于女性,50岁以上年龄组N-MID男性均小于女性,差异有统计学意义(P0.05);多元逐步回归分析中BMD与年龄、N-MID呈负相关,与BMI为正相关,男性大于女性;PMOF与BMD、年龄呈负相关,与BMI、N-MID呈正相关,男性小于女性;在不同性别、各年龄组中BMI正常组的PMOF最低,超重组最高,差异有统计学意义。其他生化指标与BMD、PMOF之间的相关关系不显著(P0.05)。结论 BMD、PMOF与性别、年龄、BMI、骨钙素均相关,其中女性OF的风险均高于男性;BMD随年龄增长而降低,骨折风险增加;BMD与BMI呈正相关,但PMOF表现为超重人群骨折风险最高,故超重亦是使骨折风险增加的危险因素。随血清骨钙素增高,BMD降低,骨折风险增高,可在一定程度上反映骨组织的新陈代谢情况。关注骨代谢生化指标变化可在一定程度上预判骨密度及PMOF水平,对骨质疏松及其骨折的的早发现、早诊断、早预防和早治疗提供一定参考及理论依据。     

中老年2型糖尿病患者骨代谢特点及骨量丢失危险因素分析

目的 探讨中老年2型糖尿病(type 2 diabetes mellitus,T2DM)患者骨代谢特点及骨量丢失危险因素.方法 选择中老年T2DM患者612例(男296例,女316例),根据骨密度(bone mineral density,BMD)水平分为骨量正常组(108例)、骨量减少组(281例)、骨质疏松组(22...     

25-hydroxy vitamin D levels in healthy premenopausal women: Association with bone turnover markers and bone mineral density

BackgroundVitamin D deficiency is very common in elderly people while there are very few reports on its incidence, determinants and metabolic consequences in young subjects.ResultsIn 608 young healthy premenopausal women participating in the BONTURNO study, levels of 25-hydroxyvitamin D [25(OH)D] below 20 ng/ml were found in almost a third of the women. Its levels were inversely (P < 0.001) related with age and body mass index (BMI kg/m²) and directly with sunlight exposure during the summer time, and latitude: i.e. the higher the latitude over Italy, the higher the 25(OH)D level. In women on contraceptive pill the mean 25(OH)D level was significantly increased even when the data were adjusted for age, BMI and sun exposure.25(OH)D levels, adjusted for age and BMI, were significantly and positively related with serum C-telopeptide of type 1 collagen, serum phosphate and spine bone mineral density (BMD) and negatively with serum PTH, serum magnesium, serum bone alkaline phosphatase (bone AP).ConclusionVitamin D deficiency is rather common in young otherwise healthy Italian women and particularly among those living in the Southern part of the country. The most close determinants of vitamin D deficiency were BMI and sunlight exposure. Vitamin D insufficiency is associated with low spine BMD and increased bone AP even in young individuals.     

Seasonal periodicity of serum vitamin D and parathyroid hormone, bone resorption, and fractures: the Geelong Osteoporosis Study.

In this population-based study, seasonal periodicity was seen with reduced serum vitamin D, increased serum PTH, and increased bone resorption in winter. This was associated with an increased proportion of falls resulting in fracture and an increased risk of wrist and hip fractures. INTRODUCTION: In a population of women who reside in a temperate climate and do not generally receive dietary vitamin D supplementation, we investigated whether seasonal vitamin D insufficiency is associated with increased risk of fracture. MATERIALS AND METHODS: An observational, cross-sectional, population-based study set in southeastern Australia (latitude 38-39 degrees S). Participants were drawn from a well-defined community of 27,203 women >/=55 years old: 287 randomly selected from electoral rolls, 1635 with incident fractures, and 1358 presenting to a university hospital with falls. The main outcome measures were annual periodicities of ultraviolet radiation, serum 25-hydroxyvitamin D [25(OH)D], serum parathyroid hormone (PTH), serum C-telopeptide (CTx), BMD, falls, and fractures. RESULTS: Cyclic variations in serum 25(OH)D lagged 1 month behind ultraviolet radiation, peaking in summer and dipping in winter (p < 0.001). Periodicity of serum PTH was the inverse of serum 25(OH)D, with a phase shift delay of 1 month (p = 0.004). Peak serum CTx lagged peak serum PTH by 1-2 months. In late winter, a greater proportion of falls resulted in fracture (p < 0.001). Seasonal periodicity in 439 hip and 307 wrist fractures also followed a simple harmonic model (p = 0.078 and 0.002, respectively), peaking 1.5-3 months after the trough in 25(OH)D. CONCLUSIONS: A fall in 25(OH)D in winter is accompanied by increases in (1) PTH levels, (2) bone resorption, (3) the proportion of falls resulting in fracture, and (4) the frequency of hip and wrist fracture. Whether vitamin D supplementation in winter can reduce the population burden of fractures requires further investigation.     

Relationship between serum 25-hydroxyvitamin D and bone resorption markers in vitamin D insufficiency

It is known that nursing-home patients with vitamin D insufficiency have elevated serum parathyroid hormone (PTH) as well as raised serum alkaline phosphatase (ALP). Although it is well known that vitamin D insufficiency and secondary hyperparathyroidism are common among the elderly in western countries, there is continuing controversy over the level of serum 25-hydroxyvitamin D [25(OH)D] necessary for bone health. We approached this issue by examining the relationships between serum 25(OH)D, ionized calcium, PTH, and ALP and the urinary bone resorption markers hydroxyproline, pyridinoline, and deoxypyridinoline, corrected for creatinine (OHPr/Cr, Pyd/Cr, and Dpd/Cr, respectively), in 486 postmenopausal women of mean age 63 (SD 9.5) years, who were referred to our osteoporosis and menopause clinics for investigation. When the patients were divided into two groups with 25(OH)D above and below 20 nmol/L, 30 nmol/L, 40 nmol/L, 50 nmol/L, 60 nmol/L, or 70 nmol/L, the most significant differences between the two groups thus derived was found at a serum 25(OH)D level of 60 nmol/L (P < 0.001 for all markers). The most significant difference between groups for serum PTH was found when the patients were divided at a serum 25(OH)D of 50 nmol/L. PTH, OHPr/Cr, Pyd/Cr, and ALP were inversely related to serum 25(OH)D. PTH was inversely related to serum ionized calcium. There was a trend for ionized calcium to be positively related to 25(OH)D, but this did not reach statistical significance. We conclude that rises in three bone resorption markers and ALP can be detected in postmenopausal women when the serum 25(OH)D level falls below 60 nmol/L. Levels above this may be required for optimal bone health.     

Biochemical parameters associated with low bone density in healthy men and women.

A causal role in age-related bone loss has been attributed to alterations in vitamin D status, the bone mineral regulating hormones, and/or renal function. We assessed biochemical parameters of bone metabolism and renal function in healthy subsets of young and old men (n = 191) and women (n = 120) and evaluated the relationships between these parameters and bone mineral density (BMD) in the radius, spine, and femur. There were no significant associations between BMD at any site and serum 25-OHD, 1,25-(OH)2D, PTH, or creatinine clearance in either young men or in young or old women, after controlling for age. In old men, however, lower radius BMD was significantly related to higher PTH and higher 1,25-(OH)2D and marginally related to lower 25-OHD values. In young men, there were unexpected but significant associations between lower femoral neck BMD and higher serum osteocalcin and urinary calcium/creatinine excretion after age adjustment. In old women, lower spine and radius BMD was also significantly correlated with higher serum osteocalcin. In this healthy, vitamin D-replete population, there were significant cross-sectional declines in BMD in the femur in young and old men and at all sites in old women. Elevated remodeling may be an important feature that contributes to reduced femoral BMD in young men and reduced spine and radius BMD in old women. However, compromised renal function or levels of 1,25-(OH)2D or elevated PTH appear to be neither necessary nor relevant as determinants of osteopenia in the spine or femur in these normal, healthy men and women.     

Impact of calcium and vitamin D insufficiencies on serum parathyroid hormone and bone mineral density: Analysis of the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV‐3, 2009 and KNHANES V‐1, 2010)

The relative contributions of calcium and vitamin D to calcium metabolism and bone mineral density (BMD) have been examined previously, but not in a population with very low calcium intake. To determine the relative importance of dietary calcium intake and serum 25‐hydroxyvitamin D [25(OH)D] concentration to calcium metabolism and bone mass in a population with low calcium intake, a total of 4662 adults (2567 men and 2095 women) ≥50 years of age from the 2009–2010 Korea National Health and Nutrition Examination Survey (KNHANES) were divided into groups according to dietary calcium intakes (quintiles means: 154, 278, 400, 557, and 951 mg/d) and serum 25(OH)D concentrations (<50, 50–75, and >75 nmol/L). Serum intact parathyroid hormone (PTH) and femoral neck and lumbar spine BMD were evaluated according to dietary calcium intake and serum 25(OH)D. Mean calcium intake was 485 mg/d; mean serum 25(OH)D concentration was 48.1 nmol/L; PTH was 68.4 pg/mL; femoral neck BMD was 0.692 g/cm²; and lumbar spine BMD was 0.881 g/cm². Lower dietary calcium intakes were significantly associated with higher serum PTH concentrations and lower femoral neck BMD, not only at lower (<50 nmol/L) but also at higher (>75 nmol/L) serum 25(OH)D concentrations. Serum PTH was highest and femoral neck BMD was lowest in the group, with a serum 25(OH)D less than 50 nmol/L. In this low‐intake population, calcium intake is a significant determinant of serum PTH and BMD at higher as well as lower 25(OH)D levels. This finding indicates that low calcium intake cannot be compensated for with higher 25(OH)D levels alone. As expected, serum 25(OH)D levels were inversely associated with serum PTH and BMD. A calcium intake of at least 668 mg/d and a serum 25(OH)D level of at least 50 nmol/L may be needed to maintain bone mass in this calcium deficient population. © 2013 American Society for Bone and Mineral Research.     

Femoral Volumetric Bone Density,Geometry, and Strength in Relation to 25‐Hydroxy Vitamin D in Older Men

Low serum 25‐hydroxy vitamin D (25(OH)D) concentrations are associated with increased hip fracture risk and decreased femoral areal bone mineral density (BMD) among elderly men. Structural dimensions of the proximal femur and volumetric BMD in cortical and trabecular compartments are also associated with hip fracture risk. However, associations of volumetric BMD or structural dimensions with serum 25(OH)D concentrations among older men remain unclear. In a random sample of 1608 men aged ≥65 years from the Osteoporotic Fractures in Men Study (MrOS), baseline serum 25(OH)D concentrations were measured by liquid chromatography/mass spectrometry assays. Femoral neck geometry and volumetric BMD derived from quantitative computed tomography included integral, cortical, and trabecular volumetric BMD; cross‐sectional area; integral and cortical volume; and cortical volume as a percent of integral volume. We studied 888 men with vitamin D, parathyroid hormone (PTH), femoral neck geometry, and BMD measures. Whole‐bone femoral strength and load‐strength ratio from finite element (FE) analysis were also available for 356 men from this sample. Multivariable linear regression was used to estimate least square means of each femoral measure within quartiles of 25(OH)D adjusted for age, race, body mass index, height, latitude, and season of blood draw. Tests of linear trend in the means were performed across increasing quartile of serum 25(OH)D levels. Mean cortical volume (p trend = 0.006) and cortical volume as a percent of integral volume (p trend < 0.001) increased across increasing quartile of 25(OH)D level. However, overall femoral neck size (area and integral volume) did not vary by 25(OH)D level. Femoral neck volumetric BMD measures increased in a graded manner with higher 25(OH)D levels (p trend < 0.001). Femoral strength, but not load‐strength ratio, increased with increasing 25(OH)D. Adjustment for PTH did not materially change these associations. We conclude that in older men, higher levels of endogenous 25(OH)D may increase whole‐bone strength by increasing femoral volumetric BMD and cortical volume. © 2014 American Society for Bone and Mineral Research.     

Skeletal Effects of Vitamin D Supplementation in Postmenopausal Black Women

Black women have lower serum 25-hydroxyvitamin D (25[OH]D) levels and higher parathyroid hormone (PTH) levels than white peers but lower bone turnover, suggesting skeletal resistance to PTH. Our objective was to determine if vitamin D supplementation (1,000?IU/day) would prevent bone loss and whether vitamin D receptor (VDR) polymorphisms modify the response. We performed a 2-year randomized, controlled, double-blind study of 1,000?IU vitamin D₃ vs. placebo in postmenopausal black women with serum 25(OH)D levels <20?ng/mL (n?=?103). Measurements of 25(OH)D, PTH, and bone turnover were evaluated at baseline and 3, 6, 12, 18, and 24?months. DNA was extracted from peripheral blood leukocytes, and genotyping was conducted using standard techniques. Spine and hip bone mineral density (BMD) was measured at baseline and every 6?months. Serum 25(OH)D increased 11?ng/mL with vitamin D supplementation (p?<?0.001), with no change in the placebo group. Vitamin D supplementation produced a significant decline in PTH at 3?months only, with no differences in bone turnover between placebo and vitamin D at any time point. Two-year changes in BMD were not significantly different between placebo- and vitamin D-treated black women at any skeletal site. Despite similar elevations in 25(OH)D, femoral neck BMD was only responsive to vitamin D supplementation in FF subjects (n?=?47), not Ff/ff subjects (n?=?31). Vitamin D supplementation does not appear to influence bone loss in black women. However, in the FF polymorphism of the VDR gene group, vitamin D supplementation may retard the higher rate of bone loss.     

Functional hypoparathyroidism in postmenopausal women with fragility fracture

IntroductionSecondary hyperparathyroidism sometimes is lacking despite authentic vitamin D insufficiency (VDI) and the concept of functional hypoparathyroidism with a protective role on bone status has been proposed. Therefore, we tested the hypothesis that its prevalence was very low in a population of women with a peripheral fragility fracture.MethodsWe conducted our study in postmenopausal women, admitted for such a fracture in our Fracture Liaison Service. All had bone mineral density (BMD), biochemical assessment and a medical visit.ResultsTwo hundred and thirty seven women (72.9 ± 11.6-year-old) were included and 90.4% had VDI (25[OH]D ≤ 30 ng/mL). Yet, 87.9% of the latter had normal PTH levels less or equal to 64 ng/L. In this population with VDI (n = 214), we found no PTH plateau level related to 25(OH)D. Since a recent study reported an increase in the risk of fracture only when 25(OH)D was below 15 ng/mL, we then used this value as a new threshold. We observed a significant difference in hip BMD between patients with 25(OH)D either less or equal to or greater than 15 ng/mL. However, 81.2% of the formers were still with normal PTH with no difference in BMD whether PTH level was above or within normal range.ConclusionIn a population of postmenopausal women with a fragility fracture, we found that 25(OH)D less or equal to 15 ng/mL was associated with significantly lower hip BMD. Even using this low threshold, we found a high prevalence of functional hypoparathyroidism and it was not associated with any difference in hip or spine BMD. Overall, our results do not support the hypothesis of a protective effect of this biological profile.     

Impaired bone mineralization accompanied by low vitamin D and secondary hyperparathyroidism in patients with femoral neck fracture

Summary

Although it is well established that a decrease in bone mass increases the risk of osteoporotic fractures, the proportion of fractures attributable to areal bone mineral density (BMD) is rather low. Here, we have identified bone mineralization defects together with low serum 25-hydroxyvitamin D (25-(OH) D) levels as additional factors associated with femoral neck fractures.

Introduction

Osteoporotic fractures of the femoral neck are associated with increased morbidity and mortality. Although it is well established that a decrease in bone mass increases the risk of osteoporotic fractures, the proportion of fractures attributable to areal BMD is rather low. To identify possible additional factors influencing femur neck fragility, we analyzed patients with femoral neck fracture.

Methods

We performed a detailed clinical and histomorphometrical evaluation on 103 patients with femoral neck fracture including dual-energy X-ray absorptiometry, laboratory parameters, and histomorphometric and bone mineral density distribution (BMDD) analyses of undecalcified processed biopsies of the femoral head and set them in direct comparison to skeletal healthy control individuals.

Results

Patients with femoral neck fracture displayed significantly lower serum 25-(OH) D levels and increased serum parathyroid hormone (PTH) compared to controls. Histomorphometric analysis revealed not only a decreased bone volume and trabecular thickness in the biopsies of the patients, but also a significant increase of osteoid indices. BMDD analysis showed increased heterogeneity of mineralization in patients with femoral neck fracture. Moreover, patients with femoral neck fracture and serum 25-(OH) D levels below 12 μg/l displayed significantly thinner trabecular bone.

Conclusion

Taken together, our data suggest that impaired bone mineralization accompanied by low serum 25-(OH) D levels is of major importance in the etiology of femoral neck fractures. Therefore, balancing serum 25-(OH) D levels and thereby normalizing PTH serum levels may counteract pronounced mineralization defects and might decrease the incidence of femoral neck fractures.     

Vitamin D and skeletal health in infancy and childhood

During growth, severe vitamin D deficiency in childhood can result in symptomatic hypocalcaemia and rickets. Despite the suggestion from some studies of a secular increase in the incidence of rickets, this observation may be driven more by changes in population demographics than a true alteration to age, sex and ethnicity-specific incidence rates; indeed, rickets remains uncommon overall and is rarely seen in fair-skinned children. Additionally, the impact of less severe vitamin D deficiency and insufficiency has received much interest in recent years, and in this review, we consider the evidence relating vitamin D status to fracture risk and bone mineral density (BMD) in childhood and adolescence. We conclude that there is insufficient evidence to support the suggestion that low serum 25-hydroxyvitamin D [25(OH)D] increases childhood fracture risk. Overall, the relationship between 25(OH)D and BMD is inconsistent across studies and across skeletal sites within the same study; however, there is evidence to suggest that vitamin D supplementation in children with the lowest levels of 25(OH)D might improve BMD. High-quality randomised trials are now required to confirm this benefit.     

脂肪肝患者25-羟维生素D与骨密度和代谢综合征相关性研究

目的 通过分析维生素D水平对脂肪肝患者代谢综合征(MetS)的影响,为MetS和低骨密度(BMD)的治疗提供基础数据。方法 通过肥胖指数和血液指标分析了150名诊断为脂肪肝的成年人的MetS比率和血清25-羟基维生素D[25(OH)D]水平。收集了有关人口统计学因素,营养摄入量,生活习惯的数据以及髋部和腰椎（L1-L4)骨密度。结果 所有受试者的平均25(OH)D水平为14 ng/mL,不足和缺乏率分别为36.0%和31.3%。MetS的比例为38.0%,MetS组的平均25(OH)D水平为12.1ng/mL。MetS组低密度脂蛋白胆固醇、三酰甘油和血糖均高于正常组,男性腰围明显高于正常组。血清25(OH)D下降,骨密度下降。 MetS患者骨密度明显低于非MetS患者(P <0.05)。结果表明,维生素D水平越低,MetS风险越高,骨密度越低。结论 血清25(OH)D水平可能是脂肪肝患者MetS和低骨密度的危险因素。     

High prevalence of vitamin K and D deficiency and decreased BMD in inflammatory bowel disease

Summary  Vitamin K and D deficiency and decreased bone mineral density (BMD) were highly prevalent in patients with inflammatory bowel disease (IBD), especially Crohn’s disease (CD). Dietary intakes of these vitamins, however, were above the Japanese adequate intakes in IBD patients, suggesting that malabsorption is the basis for hypovitaminosis K and D and decreased BMD. Introduction  We have studied the possible involvement of vitamin K and D deficiency in the pathogenesis of decreased BMD in IBD. Methods  Seventy patients with IBD were evaluated for their BMD; plasma levels of vitamin K; phylloquinone (PK), menaquinone-7 (MK-7), and 25OH-D; serum PTH, protein induced by vitamin K absence (PIVKA-II), and undercarboxylated osteocalcin (ucOC) levels; and their food intake. Results  Compared with ulcerative colitis (UC) patients, CD patients had significantly lower plasma vitamin K and 25OH-D concentrations; significantly higher serum levels of PTH, PIVKA-II, and ucOC; and significantly lower BMD scores at almost all measurement sites. More IBD patients were vitamin K deficient in bone than in liver. Multiple regression analyses revealed that low plasma concentrations of vitamin K and 25OH-D were independent risk factors for low BMD and that they were associated with the patients’ fat intake, but not with their intake of these vitamins. Conclusion  IBD patients have high prevalence of decreased BMD and vitamin K and D deficiency probably caused by malabsorption of these vitamins.     

Hip fracture patients in India have vitamin D deficiency and secondary hyperparathyroidism

Summary

This study evaluated the parameters of bone mineral homeostasis including 25(OH)D and PTH in 90 Indian patients with hip fracture and 90 controls. Hypovitaminosis D, secondary hyperparathyroidism, and biochemical osteomalacia was present in 77, 69, and 50 % patients, respectively, significantly higher compared to controls. Vitamin D deficiency is an important risk factor for hip fracture.

Introduction

The prevalence of vitamin D deficiency is not well known in hip fracture patients from India. Therefore, the present study was conducted to evaluate the parameters of bone mineral homeostasis including 25(OH)D and intact PTH in hip fracture from North India.

Methods

Ninety consecutive patients with hip fracture and similar number of age- and sex-matched controls were enrolled in the study. The fasting venous samples were analyzed for 25-hydroxyvitamin D (25-OHD), intact parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium, and phosphorus. Vitamin D deficiency was defined as serum 25-OHD of <20 ng/dl.

Results

The mean age of hip fracture subjects was 65.9?±?12.6 which was comparable in men and women. Majority of study subjects were women (70 women and 20 men). The serum 25(OH)D and calcium levels were significantly lower, whereas the intact PTH and ALP levels were significantly higher in patients compared to controls. There was significant negative correlation between serum 25(OH)D and PTH. In the hip fracture group, 76.7 % of the subjects had vitamin D deficiency, and 68.9 % had secondary hyperparathyroidism. In the control group, vitamin D deficiency and elevated PTH levels were seen in 32.3 and 42.2 %, respectively.

Conclusion

About three fourths of hip fracture patients have vitamin D deficiency, and two thirds have secondary hyperparathyroidism. Therefore, the serum 25-OHD level may be a useful index for the assessment of risk of hip fracture in India.