Association between quantitative measures of skin color and plasma 25-hydroxyvitamin D

Summary  We examined the relationship between vitamin D and skin color measured by reflectance colorimetry at an exposed and un-exposed site in 321 people. Exposed but not unexposed skin color was associated with better vitamin D status. Sun-exposure was more important than natural skin color in determining vitamin D status in our population. Introduction  Vitamin D is obtained through UV synthesis in the skin where melanin limits its synthesis. Ethnicity is often used as a proxy for skin color, but skin color varies considerably. The relation between quantitative measures of skin color and plasma 25-hydroxyvitamin D (25OHD) concentration has not been well described. Methods  The aim of this study was to determine the association between constitutive (natural) and sun-induced skin color and 25OHD in a group of Pacific People (n = 87) and Europeans (n = 255) living in NZ (46°S) in summer. Plasma 25OHD was determined and sun-induced (outer fore-arm) and constitutive (upper inner-arm) measured by reflectance colorimetry. Results  Mean (SD) 25OHD was significantly higher in Europeans than Pacific People, 88 (31) nmol/L vs. 75 (34) nmol/L, respectively. Based on constitutive skin color, 35% of participants were very light, 45% light, 16% intermediate, 4% tanned, and 0% brown or dark. Skin color at the forearm but not constitutive skin color was a significant predictor of 25OHD. Each 10° lower skin color value at the forearm (more tanning) was associated with a 5 nmol/L higher 25OHD (P < 0.001). Conclusions  Tanning but not natural skin color was an important determinant of 25OHD. Further study is needed in a population with a higher proportion of darker skin people.     

岳阳地区50岁以上人群25经维生素D水平及其与骨密度的关系

目的 通过测定269名岳阳地区50岁以上人群血清25经维生素D(25(OH)D)和骨密度(BMD)水平,分析岳阳地区50岁以上人群的维生素D ( VitD)状况,并探讨其与BMD的关系。方法 采集受试者的血清后,用电化学发光法测定血清25(OH)D水平,并同时应用双能X线吸收仪测定腰椎及髓部BMD。结果 所有受试者中,VitD严重缺乏者占24. 2 %,缺乏者占45. 0%,不足者占24. 5 %,充足者占6. 3。男、女性受试者的25(OH)D水平、腰椎及髓部的BMD间有统计学差异(P<0.001),男性高于女性。男性各年龄段间25(OH)D水平及各部位BMD无统计学差异(P=0. 101 ,P = 0. 261 ,0. 055 ,0. 170 ,0. 108 ,0. 051 ) ;女性各年龄段之间25(OH)D水平及腰椎BMD无统计学差异(P = 0. 364 , 0. 063 ) ;髓部BMD有统计学差异(P < 0. 001 ),随着年龄的增长而逐步减低。男性受试者中,不同25(OH)D水平组间股骨颈、转子间区及整髓BMD无统计学差异(P = 0. 076 , 0. 425 , 0. 122 );腰椎、大转子区BMD水平间有统计学差异(P=0. 027 , 0. 017 ) , VitD充足组腰椎BMD高于其他各组(P = 0. 005 , 0. 025 , 0. 009 );不足组、严重缺乏组大转子区BMD高于缺乏组(P = 0. 021, 0. 005 )。女性受试者中,不同25(OH)D水平组各部位BMD均无统计学差异(P = 0. 616 , 0. 739 , 0. 559 ; 0. 608 , 0. 641)。结论 在湖南岳阳地区50岁以上人群存在严重的维生素D缺乏及不足;对于维生素D状况与骨密度之间可能无直接关联,需加大样本量进一步观察。     

Serum 25-hydroxyvitamin D levels and testosterone deficiency in middle-aged Korean men: a cross-sectional study

Previous studies have demonstrated that male hypogonadism is associated with a low level of vitamin D. However, no reports have investigated the effects of vitamin D on testosterone levels in Korean men. Our aim was to investigate whether testosterone levels are associated with serum vitamin D levels and whether seasonal variation exists. This cross-sectional study analyzed serum 25-hydroxyvitamin D [25(OH)D], total testosterone (TT), and free testosterone (FT) in 652 Korean men over 40 years of age who had undergone a comprehensive medical examination. The average age of the subjects was 56.7 ± 7.9 years, and the mean serum 25(OH)D, TT and FT levels were 21.23 ± 7.9 ng ml⁻¹, 4.70 ± 1.6 ng ml⁻¹, and 8.12 ± 3.3 pg ml⁻¹, respectively. In the multiple linear regression model, 25(OH)D showed positive association with TT (β =0.137, P < 0.001) and FT (β =0.103, P = 0.008). 25(OH)D and FT showed similar seasonal or monthly variation after adjustment for age. A vitamin D deficiency [25(OH)D < 20 ng ml⁻¹] was associated with an increased risk of deficiencies of TT (<2.30 ng ml⁻¹) (odds ratio [OR]: 2.65; 95% confidence interval [CI]: 1.21–5.78, P = 0.014) and FT (<6.50 pg ml⁻¹) (OR: 1.44; 95% CI: 1.01–2.06 P = 0.048) after adjusting for age, season, body mass index, body composition, chronic disease, smoking, and alcohol use. In conclusion, we demonstrated a positive correlation between 25(OH)D and testosterone, which showed similar seasonal variation in Korean men.     

An International Comparison of Serum 25-Hydroxyvitamin D Measurements

Vitamin D status is usually assessed by measuring the serum 25-hydroxyvitamin D (25(OH)D) concentration. This mainly depends on sunshine exposure, nutrition and age. Interlaboratory variation may hamper comparison between results from different populations. This study reports cross-calibration of the 25(OH)D assays of five laboratories. In study 1, serum 25(OH)D was measured with three different assays in 104 serum samples from a large vitamin D supplementation study. The mean serum 25(OH)D level was 80% higher when measured by competitive protein binding (CPB) assay than by high-performance liquid chromatography (HPLC), while radioimmunoassay (RIA) gave intermediate values. The highest correlation was observed between RIA and HPLC (r= 0.84, p <0.01). Of the serum 25(OH)D values in the lowest quartile by HPLC, 25% were not recognized by CPB and 21% were not recognized by RIA as belonging to the lowest quartile. In study 2, the five laboratories analyzed serum 25(OH)D in eight serum samples covering the concentration range very low to high, with five different assays. The differences between the mean values for serum 25(OH)D between the laboratories with the highest and lowest values was 38%. The ranking order of individual samples according to the serum 25(OH)D value was very similar in all laboratories. The results show that 25(OH)D values from different laboratories can not be assumed to be comparable unless a careful cross-calibration has been performed. Received: 1 May 1998 / Accepted: 3 September 1998     

Renal function and 25-hydroxyvitamin D concentrations predict parathyroid hormone levels in renal transplant patients.

BACKGROUND: Recent guidelines suggest supplementation with ergocalciferol (vitamin D(2)) in chronic kidney disease stages 3 and 4 patients with elevated parathyroid hormone (PTH) levels and 25-hydroxyvitamin D (25OHD) levels <75 nmol/l. These guidelines are also applied to renal transplant patients. However, the prevalence rates of 25OHD deficiency and its association with PTH levels in renal transplant populations have not been extensively examined. We aimed to document the prevalence rates of 25OHD deficiency [defined by serum levels <40 nmol/l (<16 ng/ml)] and insufficiency [<75 nmol/l (<30 ng/ml)] in a single renal transplant centre, and examine its relationship with PTH levels. METHODS: Serum 25OHD and PTH concentrations were measured in 419 transplant patients attending a single renal transplant clinic over a 4-month period. Demographic and biochemical data were also collected, including serum creatinine, calcium, phosphate and albumin. Simple and multiple linear regression analysis were performed. RESULTS: In 27.3% of the patients, 25OHD deficiency was present, and 75.5% had insufficiency. On univariate analysis, 25OHD, serum albumin and estimated glomerular filtration rate (eGFR) were significantly associated with PTH levels (P < 0.0001, P = 0.004 and P < 0.0001, respectively). Multiple linear regression demonstrated that only 25OHD, eGFR and serum phosphate were significantly predictive of PTH levels (R(2) = 0.19, P < 0.0001). In this model, a 75 nmol/l increase in 25OHD will only result in a maximal reduction in PTH of 2.0 pmol/l. CONCLUSIONS: We conclude that 25OHD deficiency and insufficiency are common in renal transplant patients and may exacerbate secondary hyperparathyroidism. However, 25OHD, eGFR and phosphate only account for 19% of the variability in PTH levels. In addition, even a large increase in serum 25OHD levels is likely to result in only a small reduction in PTH. Therefore, alternative approaches to managing hyperparathyroidism in renal transplant recipients rather than supplementation with ergocalciferol are warranted.     

骨质疏松症患者血清25-羟维生素D水平的研究

目的：调查了解西安地区骨质疏松症患者体内维生素D 水平的状况。方法随机选取2012年12月－2013年11月我科440例骨质疏松症患者,采集其清晨空腹静脉血,用Cobase 6000型电化学发光仪（瑞士罗氏诊断）检测血中25（OH）D的水平,按照2012年12月－2013年5月为冬春季和2013年6月－2013年11月为夏秋季进行分组,用SPSS13．0软件进行数据分析。结果共调查了440例骨质疏松症患者,其中女性患者数量远大于男性患者,这些患者普遍存在着维生素D水平不足现象,其中维生素D严重缺乏和缺乏所占比例较大,男女两组在年龄和血清25（ OH） D水平上均无统计学差异,而且冬春季患者体内维生素D的水平要低于夏秋季的患者。结论本研究显示西安地区骨质疏松症患者维生素D不足现象比较普遍,男性女性之间无明显差别,而且体内维生素D水平与季节的变化有关,为骨质疏松症的防治提供一定的数据参考。     

Serum levels of 25-hydroxyvitamin D in postmenopausal osteoporosis

Summary Serum concentrations of 25-hydroxyvitamin D were measured in a group of women with symptomatic postmenopausal osteoporosis, assessed by bone biopsy. A competitive protein binding assay was used, which included a chromatographic step. Accurate surveys of dietary or therapeutic vitamin D intake and light environment were obtained in each patient. Women with severe postmenopausal osteoporosis were found to have significantly (P<0.001) higher serum levels of 25-hydroxyvitamin D than age-matched normal women, the mean values being 27.5 ng/ml (±13.6 SD) and 8.2 ng/ml (±5.7), respectively. The authors hypothesize that the reduction in 1,25-dihydroxyvitamin D, recently reported in postmenopausal osteoporotic women, might be responsible for the increased serum levels of 25-hydroxyvitamin D through an inadequate product inhibition of liver vitamin D 25-hydroxylase.     

苏州市0-6岁儿童骨密度调查及其与25羟维生素D关系研究

目的探究苏州市0-6岁儿童骨密度养状况和影响因素及其与25羟维生素D关系,为预防儿童骨密度不足提供科学依据。方法选择苏州地区0-6岁儿童481名作为研究对象进行体格测量和相关问卷调查,并采用免疫层析法测定血清25羟维生素D水平和应用定量超声仪检测骨密度。结果 (1)定量超声骨密度Z值平均水平为-0.03±0.87,骨密度不足者57名(11.90%)。(2)单因素分析结果显示年龄(χ~2=10.38,P0.001)、肉类(t=3.01,P=0.003)摄入和蛋类摄入(t=2.15,P=0.036)、睡眠时间(χ~2=8.63,P=0.013)、BMI(χ~2=11.89,P=0.003)、维生素D营养状况(χ~2=18.37,P0.001)与儿童骨密度水平有关。(3)二元logistic回归分析显示肥胖(BMI18)是影响儿童骨密度危险因素(OR=4.730,P=0.003),维生素D充足是其保护因素(OR=0.133,P0.001)。(4)血清25羟维生素D水平和骨密度值之间存在正性直线相关关系(P0.001)。结论 1岁内婴儿是防治儿童骨强度不足主要人群,且学龄前儿童骨密度监测工作不可忽视。防治肥胖和合理维生素D补充有利于提高儿童骨密度,促进骨骼健康发展。     

Threshold value of serum 25-hydroxyvitamin D concentration in relation to elevated serum parathyroid hormone concentrations in elderly Japanese women

This study was designed to determine the threshold value for 25-hydroxyvitamin D [25(OH)D] concentration in relation to elevated serum parathyroid hormone (PTH) concentrations in elderly Japanese women. The subjects were 582 noninstitutionalized, ambulant women who lived in a community in Japan. Serum 25(OH)D concentrations were determined using the Nichols Advantage chemiluminescent assay, and serum intact PTH concentrations were determined with a two-site immunoradiometric assay. Demographic characteristics, calcium intake, and serum 1,25(OH)₂D levels were also determined. The average age, body mass index (BMI), and calcium intake of the subjects were 74.5 years (SD 4.5), 23.3 kg/m² (SD 3.4), and 579 mg/day (SD 248), respectively. The serum log-transformed intact PTH concentration was significantly predicted by the serum 25(OH)D concentration (r = −0.147, P = 0.0004), but not by age, BMI, the serum log-transformed 1,25(OH)₂D concentration, or the log-transformed calcium intake. Analysis of variance with Dunnett's multiple comparisons showed that mean serum intact PTH concentrations with serum 25(OH)D concentrations less than 30 nmol/l (mean intact PTH = 5.89 pmol/l, P < 0.0001) and in the range 30–39 nmol/l (mean intact PTH = 4.54 pmol/l, P = 0.0067) were significantly higher than mean intact PTH concentrations for serum 25(OH)D concentrations greater than 50 nmol/l (mean intact PTH = 3.65 pmol/l, the baseline level), but the mean serum intact PTH concentration for 25(OH)D concentrations in the range 40–49 nmol/l (mean intact PTH = 3.70 pmol/l, P = 0.9975) was not. We conclude that serum 25(OH)D for ambulant elderly Japanese women should be maintained at 40 nmol/l or higher.     

未绝经女性甲亢患者血25羟维生素D水平与骨密度的关系

目的 观察未绝经女性甲亢患者骨密度及血钙、血磷、血碱性磷酸酶（ALP）、血浆25羟维生素D[25(OH)D]、血浆甲状旁腺激素（PTH）水平变化,分析未绝经女性甲亢患者血浆25(OH)D与骨密度的关系。方法 选取50例初发或复发的未绝经女性甲亢患者,51例正常对照人群,应用双能X线吸收仪（DXA）测定腰椎1-4、股骨颈、股骨大转子、Ward三角和全股骨的骨密度,电化学发光法测定血浆25(OH)D和PTH,生化法测定血钙、磷、ALP。结果 甲亢组L1、Ward三角骨密度均低于对照组,差异有统计学意义。与对照组相比,甲亢组血钙、血ALP、血浆25(OH)D水平升高,血浆PTH降低,差异均有统计学意义。甲亢组维生素D缺乏17例(34%) , 不足19例(38%) , 充足14例(28%)。对照组维生素D缺乏30例(59%) , 不足18例(35%), 充足3例(6%)。相关分析示,两组血浆25（OH）D与L1、L2、L3、L4、L1-4、股骨颈、股骨大转子、Ward三角、全股骨骨密度均无相关性。Pearson相关分析示,甲亢组血浆25(OH)D与PTH呈负相关（r=-0.378,P<0.01）。结论 未绝经女性甲亢患者L1、Ward三角骨密度降低。未绝经女性甲亢患者血浆25(OH)D升高,可能与高血钙、PTH分泌抑制、高血磷导致1-α-羟化酶活性降低有关。未绝经女性甲亢患者血浆25(OH)D水平与骨密度无直接关系。     

Age-related decrease in serum 25-hydroxyvitamin D concentrations in the frail elderly: a longitudinal study

Several cross-sectional studies have demonstrated an age-related decrease in serum 25-hydroxyvitamin D [25(OH)D] concentrations. No prospective studies, however, have been conducted to examine this correlation to date. The objectives of this study were to measure age-related changes in serum 25(OH)D concentrations and to identify predictors of change in serum 25(OH)D concentrations in the frail elderly during a 2-year follow-up period. Eighty elderly subjects (48 women and 32 men) were selected from people utilizing the long-term care insurance system in a community in Japan. All subjects participated in both the baseline and follow-up (2 years later) medical examinations. Baseline measurements included age, height, body mass index, and weight. Additionally, levels of activities of daily living (Barthel index), grip strength, lifestyle, serum 25(OH)D, intact parathyroid hormone (PTH), albumin, total protein, and creatinine concentrations were also determined at baseline. The average age of the subjects was 82.1 years (SD, 8.8). The 2-year decrease in serum 25(OH)D concentrations was calculated to be 6 nmol/l. Multiple linear regression analyses found that the 2-year change (Δ) in the log-transformed 25(OH)D was associated with Δalbumin (β = 0.503, R ² = 0.288, P < 0.0001), and Δlog-transformed intact PTH was associated with baseline creatinine (β = 0.453, R ² = 0.142, P = 0.0006) and Δlog-transformed 25(OH)D (β = −0.512, R ² = 0.103, P = 0.0037). In conclusion, serum 25(OH)D concentrations decreased in the 2-year follow-up. This information is useful for the maintenance of vitamin D status and prevention of vitamin D insufficiency in the frail elderly.     

老年女性血清25-羟基维生素D的独立相关因素

目的通过筛选老年女性血清25-羟基维生素D[25(OH)D]的独立相关因素,寻找提高老年女性血清25(OH)D的方法。方法对280例老年女性进行伴随疾病和生活方式的调查,并进行骨代谢、血液生化、性激素和贫血等指标的检测,运用多元回归分析方法筛选老年女性血清25(OH)D的独立相关因素。结果老年女性血清25(OH)D的独立相关因素包括血PTH(β=-0.097,P0.01)、血磷(β=-18.144,P0.01)、血钙(β=19.912,P0.01)、服用复方钙剂(β=5.362,P0.01)和晒太阳(β=0.974,P0.05)。结论坚持晒太阳、服用复方钙剂和补充维生素D,可能是提高老年女性血清25(OH)D水平的重要方法。     

血清25-羟维生素D浓度检测对膝骨关节炎临床诊疗意义

目的：研究与探讨血清25－羟基维生素D浓度检测对膝骨关节炎临床诊疗的指导意义。方法随机抽取2011年6月至2011年10月以及2012年6月至2012年10月期间骨科门诊主诉有膝关节疼痛患者1174名,采用罗氏诊断试剂盒检测患者血清中的25－羟基维生素D浓度。结果1174例患者平均年龄（53．61±15．10）岁,血清25－羟维生素D浓度平均值为15．55 ng／ml,维生素D缺乏者（＜20 ng／ml）占48．12％（524例）,其中严重缺乏者（＜10 ng／ml）占26．35％（287例）。2011年测得血清25－羟基维生素D浓度平均值为13．27 ng／ml（参考值为11．10～42．90 ng／ml）;2012年测得血清25－羟基维生素D浓度平均值为22．53 ng／ml（参考值为20～32 ng／ml）。结论血清25－羟基维生素D浓度检测在膝骨关节炎诊疗中具有重要指导意义。本次研究中应用的罗氏诊断血清25－羟维生素D3检测试剂参考值有波动,直接导致2011年度与2012年度同期所检测出的患者血清25－羟基维生素D浓度存在一定的偏差。     

25羟基维生素D与2型糖尿病患者动力性平衡功能的相关性分析

目的了解2型糖尿病患者25羟基维生素D水平与动力性平衡功能的关系及影响因素。方法选取2016年8月至2017年6月在我科住院的2型糖尿病患者235例,并根据25羟基维生素D水平将患者分为严重缺乏组、缺乏组、不足组及充足组。所有患者测定身高、体重、腰围、血压、空腹血糖、Hb A1c、25羟基维生素D,测定股骨骨密度、下肢震动阈值、踝臂指数,测定动力性平衡指标:站起测试(CRT)、走直线步态测试(TGT)、2.4米行走测试。结果四组间年龄、空腹血糖、糖化血红蛋白、收缩压、舒张压、腰围、体重指数之间差异均无统计学意义。与缺乏组、不足组及充足组相比,严重缺乏组股骨骨密度显著降低,差异具有统计学意义(P0.05),踝臂指数也显著降低;与不足组及充足组相比,缺乏组的踝臂指数显著降低,差异具有统计学意义(P0.05)。与不足组及充足组相比,严重缺乏组及缺乏组下肢震动阈值显著降低,差异具有统计学意义(P0.05)。与缺乏组、不足组及充足组相比,严重缺乏组的站起测试时间明显延长,缺乏组的站起测试时间较不足组延长,且缺乏组的站起测试较不足组及充足组延长,差异具有统计学意义。(P0.05)。与缺乏组、不足组及充足组相比,严重缺乏组的2.4米行走测试时间明显延长,缺乏组的2.4米行走测试时间较不足组延长,差异具有统计学意义(P0.05)。与缺乏组、不足组及充足组相比,严重缺乏组走直线步态测试正常的患者比例明显降低,差异具有统计学意义(P0.05)。多元回归分析显示,站起测试、2.4米行走测试为25羟基维生素D的独立影响因素,应用Logistic回归分析,结果显示25羟基维生素D及年龄与走直线步态相关。结论在2型糖尿病患者中25羟基维生素D水平与站起测试、2.4米行走测试之间存在独立负相关,与走直线步态测试之间存在独立的正相关。对糖尿病患者进行25羟基维生素D的筛查及补充仍有待进一步研究。     

Serum 25-hydroxyvitamin D, parathyroid hormone, and bone mineral density in men: the Rancho Bernardo study

Introduction This study examined the distribution and determinants of serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) and their associations with bone mineral density (BMD) at the hip and spine in 414 older men (mean age 74 years) living in southern California.Methods At a clinic visit (1997–2000), demographic and lifestyle information, fracture history, and medication use were recorded; venous blood for serum 25OHD and PTH was obtained; and BMD was measured at the hip and spine.Results Only one man had vitamin D deficiency (25OHD <20 nmol/l), but 15.5% of the men had high parathyroid levels (PTH ≥65 pg/ml). The mean 25OHD and PTH levels were 109.0 nmol/l and 50.3 pg/ml, respectively. Overall, 21.5% used calcium and 9.7% used vitamin D supplements. Serum 25OHD decreased with age and was lowest in the winter; levels were higher in supplement users (vitamin D and/or calcium; p<0.01). Serum PTH did not vary by age or season, and it was lower in supplement users (p<0.01). After excluding 12 men who were outliers for serum 25OHD and PTH, there was no significant correlation between serum 25OHD and PTH (r=−0.05, p=0.3). In multiple adjusted models, serum 25OHD was positively associated with BMD at the hip (p=0.01) and spine (p=0.001). Serum PTH was moderately and inversely associated with BMD at the hip (p=0.04) but not at the spine (p=0.77).Conclusion We conclude that serum 25OHD is associated with bone health in older, community-dwelling men.     

2型糖尿病患者血清25-经维生素D水平与骨密度的关系

目的 探讨2型糖尿病患者不同血清25-( OH) D水平与骨密度的关系。方法 选择住院的2型糖尿病患者288例,根据25-( OH) D水平对其进行分组：25-( OH) D>30ng/mL为维生素D充足组;20ng/mL <25-( OH ) D≤30 ng/mL为维生素D不足组;l0 ng/mL <25-( OH) D <20 ng/mL为维生素D缺乏组;25-( OH) D <10ng/mL为维生素D严重缺乏组。采用双能X线骨密度仪(DXA)测量受试者腰椎L1-4、股骨颈及全髓的骨密度。分析不同水平25-( OH ) D与骨密度的关系。结果 维生素D充足组、维生素D不足组、维生素D缺乏组、维生素D严重缺乏组的患者例数(所占比例)分别为10例(3. 5%) ,74例(25.7%) ,177例(61.5%) ,27例(9.3%)。不同性别组25-( OH ) D水平无明显差异,但是女性患者的腰椎L1-4、股骨颈、全髋的骨密度均较男性低。pearscm相关分析显示25-( OH) D水平与腰椎L1-4、股骨颈、全髓的骨密度均无相关性(分别为r=0.080 P=0.262;r=0. 139 P=0. 051;r=0.068 P=0. 342)。结论 2型糖尿病患者25-( OH) D水平与腰椎L1-4、股骨颈、全髓的骨密度均无明显相关性。     

Effect of ergocalciferol supplementation on serum parathyroid hormone and serum 25-hydroxyvitamin D in chronic kidney disease

AIM: To assess the impact of the administration of ergocalciferol on serum parathyroid hormone levels at different stages of chronic kidney disease (CKD). METHODS: A continuous series of 85 patients with stages 3-5 CKD but excluding patients on dialysis referred to the Kaiser Kidney Program were followed. Baseline serum intact parathyroid hormone (iPTH) and serum 25(OH)D levels were measured. All patients were administered ergocalciferol in doses ranging from 800 iu/day to 100,000 iu/week. We obtained serum levels of iPTH and 25(OH)D for a post-treatment endpoint after a median treatment period of 90 days. RESULTS: Pre- and post-treatment serum iPTH levels displayed a mean difference of 2.8 pmol/L (95% CI 1.3-4.4, P < 0.001). Patients with stage 4 CKD had a mean difference of 3.6 pmol/L (95% CI 1.7-5.5, P < 0.001) between pre- and post-iPTH levels. Serum iPTH levels decreased among CKD stages 3 and 5, but were not statistically significant. All CKD groups analysed in the present study had significant increases in serum 25(OH)D levels. None of the study population required cessation of vitamin D therapy and no adverse outcomes were reported. CONCLUSION: Ergocalciferol supplementation appears a safe and effective treatment for CKD populations which may raise levels of serum 25(OH)D levels and decrease iPTH levels.     

肌注维生素D2治疗维持性血液透析患者25羟维生素D缺乏的临床观察

目的分析维持性血液透析患者的血清25-羟维生素D[25(OH)D]水平,探讨肌注维生素D2注射液治疗25羟维生素D缺乏的作用。 方法检测我院2020年12月至2021年2月170例维持性血液透析患者空腹血清25(OH)D水平,根据血清25(OH)D水平将患者分为严重缺乏组、缺乏组、不足组和正常组。分析血清25(OH)D水平与患者性别、年龄、透析龄、血红蛋白、白蛋白、血钙、血磷、全段甲状旁腺激素(iPTH)的相关性。其中86例维生素D缺乏或不足的血透患者,随机分为对照组(n＝43)和治疗组(n＝43),对照组给予常规治疗,治疗组在对照组基础上给予肌注维生素D2 (20万单位,1次/2周),连续3个月。比较患者治疗前后血清25(OH)D、血红蛋白、白蛋白、钙、磷、iPTH水平的变化,并观察不良反应情况。 结果170例患者中,维生素D严重缺乏组33例(19.4%),缺乏组33例(19.4%),不足组70例(41.2%),正常组34例(20%)。男性25(OH)D水平显著高于女性(P<0.05)。正常组与维生素D缺乏组和不足组在透析龄、血红蛋白、白蛋白差异方面均具有统计学意义(P<0.05)。血清25(OH)D与年龄、血钙、血磷、甲状旁腺激素无显著相关性(P>0.05)。多元线性逐步回归分析显示,血清25(OH)D与血红蛋白、白蛋白具有相关性(P<0.05)。肌注维生素D2 3月后可使血液透析患者的25(OH)D水平显著上升(P<0.05),同时血红蛋白、血清白蛋白、磷上升(P<0.05),对血钙、iPTH无显著影响(P>0.1)。 结论维持性血液透析患者维生素D缺乏发生率高,血清25(OH)D水平与性别、贫血、营养不良存在密切关系,肌注维生素D2可改善血透患者贫血、营养不良情况,但可能带来血磷升高。     

Association between 25-hydroxyvitamin D deficiency and cardiovascular disease in type 2 diabetic patients with mild kidney dysfunction.

BACKGROUND: A potentially modifiable and underestimated risk factor for cardiovascular disease (CVD) in subjects with kidney dysfunction is 25-hydroxyvitamin D deficiency, although the relationship between inadequate vitamin D status and manifest CVD in type 2 diabetic subjects with mild kidney impairment has not been extensively examined. METHODS: We evaluated the relationship between serum 25-hydroxyvitamin D concentrations, baseline kidney function (estimated using the modification of diet in renal disease equation) and manifest CVD (myocardial infarction, angina, ischaemic stroke, coronary revascularization or carotid endarterectomy) among 462 consecutive patients with type 2 diabetes. RESULTS: In the whole population, the mean age was 62+/-7 years, 64% were men, 76.3% had hypertension and the mean estimated glomerular filtration rate (GFR) was 94+/-33 ml/min/1.73 m(2). Kidney function was strongly and inversely associated with CVD. In multivariate logistic regression analysis, there was an inverse association between serum 25-hydroxyvitamin D concentrations and prevalent CVD [odds ratio 0.95 (95% CI 0.92-0.98; P=0.001)] in the whole population independent of baseline kidney function and other known risk factors. Additionally, the association between serum 25-hydroxyvitamin concentrations and CVD [odds ratio 0.97 (95% CI 0.94-0.99; P=0.045)] remained statistically significant in participants in the lowest estimated GFR tertile after adjustment for potential confounders. CONCLUSIONS: Decreased 25-hydroxyvitamin D concentrations are independently associated with prevalent CVD in type 2 diabetic patients with mild kidney dysfunction.     

Effect of the administration of 1,25-dihydroxyvitamin D3 on serum levels of 25-hydroxyvitamin D in postmenopausal osteoporosis

Summary Serum concentrations of 25-hydroxyvitamin D were measured in a group of women with symptomatic postmenopausal osteoporosis, before and after long-term treatment with physiological doses of 1,25-dihydroxyvitamin D₃. A competitive protein binding assay was used, which included a chromatographic step. The treatment resulted in a significant decrease in serum 25-hydroxyvitamin D levels that were higher than normal in basal conditions, the mean values before and after therapy being 27.7 ng/ml (±17.1 SD) and 19.7 ng/ml (±12.7), respectively. These findings seem to confirm the hypothesis that an inadequate product-inhibition of liver 25-hydroxylase is responsible for the increased basal levels of 25-hydroxyvitamin D found in postmenopausal osteoporosis.