玻璃遮挡日光对大鼠血清骨碱性磷酸酶与25-羟维生素D水平影响的研究

目的 研究玻璃遮挡日光对大鼠血清骨碱性磷(bone alkaline phosphatase,BALP)与25-羟维生素D[25-hydroxyvitamin D,25(OH)D]水平的影响,探讨室内日光照射与维生素D代谢的关系.方法 2006年9月至11月选用21日龄Wistar大鼠36只,随机分为直接日光照射组、双层玻璃遮挡日光照射组和避光组.3组均喂食维生素D缺乏饲料,实验期60d.每日测量日光中紫外线强度及经玻璃遮挡后紫外线强度,观察3组大鼠血清BALP和25(OH)D水平的差异.结果 (1)由于日晒条件不同,紫外线暴露程度差异很大:双层玻璃遮挡后的紫外线强度削减了85.1%;(2)血清BALP日光照射组为(37.79±3.11)U/L,玻璃遮挡组为(36.44±2.95)U/L,避光组为(51.82±7.62)U/L;日光照射组略高于玻璃遮挡组,差异无统计学意义(PO.05),但两组均显著低于避光组,差异有统计学意义(P相似文献   

经玻璃紫外线照射对大鼠25-羟维生素D水平及骨代谢的影响

目的：目前研究发现B型紫外线照射与血清25-羟维生素D［25-hydroxy vitamin D, 25-（OH）D］水平有剂量-效应关系,并且维生素D与骨代谢相关。该研究探讨经玻璃紫外线照射对大鼠25-（OH）D及骨代谢的影响。方法：选用30只Wistar大鼠建立不同紫外线暴露方式的动物模型,饲以缺乏维生素D饮料,随机分为避光组,紫外线直接照射160 min组,简称直射组,紫外线经单层玻璃照射160 min组,简称经玻组。每组各10例。21 d实验结束时,测定各组大鼠血清25-(OH) D、甲状旁腺激素(parathyroid hormone, PTH)、骨碱性磷酸酶(bone alkaline phosphatase, BALP)、骨钙素(osteocalcin, OC)和骨Ⅰ型胶原羧基末端肽(carboxyterminal cross-linked telopeptide of type I collagen, ICTP)的浓度及骨密度(bone mieral density, BMD)。结果：经玻组骨密度（BMD）为0.036±0.002 g/cm2,显著高于避光组(P<0.01); ICTP浓度0.181±0.067 μg/L,显著低于避光组(P<0.01);PTH、25-（OH）D、BALP及OC浓度分别为3.72±0.38 pg/mL、28.67±1.35 nmol/L、25.03±4.65 μg/mL和0.559±0.067 ng/mL,与避光组差异无显著性（P>0.05）。 经玻组BALP和ICTP水平及BMD与直射组差异无显著性(P>0.05);OC和PTH浓度显著高于直射组(P<0.05);25-（OH）D水平显著低于直射组（P<0.01）。结论：经单层玻璃的紫外线照射不能显著提高血浆25-（OH）D水平,但可降低维生素D缺乏造成的骨转化率升高并提高骨密度,与直接紫外线照射达到相似效果。［中国当代儿科杂志,2009,11（2）：138-141］     

维生素D及其受体与肾盂输尿管连接部狭窄相关性的初步研究

目的初步分析维生素D及其受体与肾盂输尿管连接部狭窄(ureteropelvic junction obstruction,UPJO)发生的相关性。方法选择2016年3月1日至2016年10月31日上海交通大学医学院附属上海儿童医学中心小儿泌尿外科收治的因UPJO行离断式肾盂输尿管成形术的患儿为UPJO组(n=10),因肾脏肿瘤行肾与输尿管切除术的患儿为对照组(n=8)。收集两组术前血标本检测维生素D三项(25-羟维生素D 2、25-羟维生素D 3及总25-羟维生素D的含量)。取两组术中标本采用ELISA法,检测维生素D受体(vitamin D receptor,VDR)、转化生子因子(transforming growth factor-β,TGF-β)及钙黏蛋白E的含量。结果两组术前血标本中25-羟维生素D 2、25-羟维生素D 3及体内总25-羟维生素D的含量均无统计学差异(P>0.05)。UPJO组VDR、TGF-β、钙黏蛋白E的平均值分别为(771.6±70.57)ng/每克总蛋白,(131.0±10.33)ng/每克总蛋白及(125.5±10.98)ng/每克总蛋白;对照组分别为(2128±251.8)ng/每克总蛋白,(82.3±6.834)ng/每克总蛋白及(386.6±78.71)ng/每克总蛋白。两组UPJ标本中VDR、TGF-β、钙黏蛋白E水平的差异有统计学意义(P<0.05)。结论UPJO组VDR表达量显著低于对照组,提示VDR可能与UPJO发生相关,初步推测其机制可能是肾盂输尿管连接部VDR表达量减少引起TGF-β表达量明显升高,使得肾盂输尿管连接部的组织纤维化加重,进而导致或加重UPJO。     

肥胖症儿童脂溶性维生素A、D、E水平及其影响因素北大核心CSCD

目的调查肥胖症儿童脂溶性维生素A、D、E水平,并分析其影响因素。方法选取2019年1月至2021年4月就诊于西安市儿童医院营养科的273例肥胖症儿童(肥胖症组)为研究对象,同期健康体检的226例正常体重儿童为对照组。对两组儿童进行体格及体成分的测量,并检测血清维生素A、D、E浓度。结果与对照组比较,肥胖症组血清维生素A[(1.32±0.21)μmol/L vs(1.16±0.21)μmol/L]、维生素E[(9.3±1.4)mg/L vs(8.3±1.2)mg/L]水平较高(P<0.001),25羟维生素D[25-hydroxyvitamin D,25(OH)D]水平[(49±22)nmol/L vs(62±24)nmol/L]较低(P<0.001)。在肥胖症组中,边缘型维生素A缺乏率为5.5%(15/273),维生素D缺乏/不足率为56.8%(155/273),维生素E不足率为4.0%(11/273)。控制体重指数和腰身比后,肥胖症儿童维生素A水平与年龄呈正相关(P<0.001),维生素E和25(OH)D水平与年龄呈负相关(P<0.001)。在控制年龄因素后,未发现肥胖症儿童血清维生素A、维生素E、25(OH)D水平与其肥胖程度、体脂百分比、肥胖时长的相关性,但维生素A和维生素E水平与其腰身比呈正相关(P<0.001)。结论肥胖症儿童的血清维生素A和维生素E水平较高,尤其是腹型肥胖者,而血清维生素D营养状况较差,且随着年龄的增长,状况愈差。因此,应关注肥胖症儿童维生素D营养状况并积极补充。     

维生素D受体基因多态性与维生素D缺乏性佝偻病易感性的研究

目的 通过研究维生素D受体(VDR)基因多态性与维生素D缺乏性佝偻病易感性的相关性,探讨维生素D缺乏性佝偻病的遗传易感因素。方法 利用限制性内切酶FokI,应用聚合酶链反应-限制性片段长度多态性(PCR—RFLP)分析、基因测序等技术测定48例维生素D缺乏性佝偻病患儿(病例组)和92名正常儿童(对照组)的VDR基因多态性,比较两组VDR基因型和等位基因的分布频率,并计算基因型优势比(OR)。结果 在48例佝偻病患儿中FF、Ff和ff基因型分布频率分别为46％、33％和21％;而在92名正常儿童中FF、Ff和ff基因型分布频率分别为22％、52％和26％。两组VDR基因型的分布频率差异有显著性(x^2=8．912,P=0．012),病例组中FF基因型占明显优势(OR=3．046)。两组VDR基因等位基因的分布频率差异也有显著性(x^2=5．451,P=0．020),病例组中F等位基因分布频率高于对照组。结论 VDR基因多态性与维生素D缺乏性佝偻病有相关性,提示VDR基因多态性可能在决定个体维生素D缺乏性佝偻病遗传易感性方面有重要作用。     

维生素D缺乏性佝偻病遗传易感性的研究

目的：遗传因素是否参与维生素D缺乏性佝偻病目前尚未明了。拟通过研究维生素D受体基因多态性与维生素D缺乏性佝偻病易感性的相关性,探讨维生素D缺乏性佝偻病的遗传易感性。方法：应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析技术检测159例维生素D缺乏性佝偻病儿童和78例正常儿童(对照组)维生素D受体(VDR)基因FokI位点的多态性,比较两组之间VDR基因型和等位基因的频率。结果：维生素D缺乏性佝偻病患儿和对照组儿童的VDR基因FokI位点基因型分布频率分别为:FF(37%),Ff(51%),ff(12%)和FF(18%),Ff(55%),ff(27%),两组之间的差异有显著性(χ20.01(2)=9.210,χ2=13.3880,P<0.01);佝偻病患儿和对照组儿童的VDR基因FokI位点等位基因分布频率分别为:F(63%),f(37%)和F(46%),f(54%),两组之间的差异有显著性(χ2=6.18,P<0.05)。佝偻病患儿F等位基因分布频率明显高于对照组人群(63%vs46%)两组之间的差异有显著性;而佝偻病患儿f等位基因频率显著低于对照组(37%vs 54%)。结论：VDR基因FokI酶切位点的多态性可能与维生素D缺乏性佝偻病的遗传易感性有关。     

维生素D受体基因多态性与维生素D缺乏性佝偻病的关系

维生素D缺乏性佝偻病(简称佝偻病)是由于儿童体内维生素D不足引起钙、磷代谢紊乱,使正在生长的骨骼在成骨过程中不能正常沉着钙盐而产生的一种以骨骼病变为特征的全身慢性营养性疾病.目前认为环境因素及营养因素等是主要致病原因,但遗传因素在其发生发展中的作用正逐渐受到重视.维生素D是人体内钙稳态和骨代谢的主要调节因子之一,其在体内的主要活性代谢产物是1,25-(OH)2D3.维生素D受体(vitamin D receptor,VDR)是介导1,25-(OH)2D3发挥生物学效应的核内生物大分子,VDR是由VDR基因编码,因此VDR基因是研究骨代谢性疾病遗传基础的候选基因之一.文章就VDR基因多态性与佝偻病遗传易感性之间的关系作一综述.     

维生素D受体基因型与营养性佝偻病

营养性佝偻病是维生素D缺乏所致的钙、磷代谢障碍和骨骼异常。有关其环境因素 ,包括营养因素的致病原因目前基本得到肯定 ,但对其遗传学方面的致病机制探讨较少。维生素D受体(VDR)是介导1,25(OH) 2 D3 发挥生物效应的核内生物大分子 ,对维持机体的骨钙动态平衡起重要作用。近年研究表明 ,VDR基因是骨代谢遗传基础的侯选基因之一 ,VDR基因型 (VDRalleles)与骨密度 (BMD)、骨量丢失和肠道钙吸收存在一定关联。VDRalleles与营养性佝偻病是否相关 ,国内外尚无深入研究 ,但VDRalleles与骨钙代谢的诸多研究将有助于推断营养性佝偻病与V…     

维生素D与水通道蛋白的研究进展

维生素D是一种脂溶性类固醇激素,通过与维生素D受体(vitamin D receptor,VDR)结合构成1,25 (OH)2D3/VDR信号通路参与调节机体钙磷代谢、糖代谢、脂代谢、水代谢等多种生物功能的调节.水通道蛋白是一类相对分子质量较小的疏水跨膜蛋白,在特殊的组织或细胞中如肾小管、内分泌腺、红细胞等细胞膜上特异表达,参与体内水平衡及代谢的调节.维生素D可以通过抑制肾素-血管紧张素系统在糖尿病肾病等疾病中起积极的作用,而水通道蛋白作为评价肾脏疾病进展及肾脏功能的新指标逐渐走进人们的视线,有研究证实维生素D在参与调节水通道蛋白的表达,维生素D和水通道在肾脏损伤及慢性肾脏疾病发挥着重要作用.     

维生素D受体基因多态性与儿童铅易感性的关系

目的　了解某铅污染较重矿区汉族儿童维生素D受体 (VDR)基因多态性的分布状况 ,探讨维生素D受体基因多态性与儿童铅易感性间的关系。方法　整群抽取矿区幼儿园 5～ 6岁汉族儿童 12 0名。研究VDR等位基因 (VDRB和VDRb)的出现频率并测定血铅水平 ,同时问卷调查每位研究对象血铅水平的相关因素。结果　 ( 1)所研究儿童VDRBB型 2例 ,占 1 7% ;VDRBb型 11例 ,占9 2 % ;VDRbb型 10 7例 ,占 89 2 % ;( 2 )携有VDRB等位基因的儿童血铅平均值 [( 0 910 8± 0 2 650 )μmol/L]明显高于VDR基因型为bb者 [( 0 740 1± 0 2 70 1) μmol/L] (t =2 155,P <0 0 5)。 ( 3 )儿童血铅水平相关因素分析发现 :VDR基因型 ,燃料类型及母亲文化程度等 7个因素与血铅显著相关 ,采用多元逐步回归分析后 ,发现VDR基因型对血铅水平的影响在排除协变量影响后仍有显著的统计学意义。结论　本组儿童VDR基因存在遗传多态性 ;携有VDRB等位基因的儿童对铅易感性较高 ,可能成为铅毒性作用的高危人群     

Serum vitamin D levels are lower in Australian children and adolescents with type 1 diabetes than in children without diabetes

Vitamin D is synthesised in the skin through the action of UVB radiation (sunlight), and 25‐hydroxy vitamin D (25OHD) measured in serum as a marker of vitamin D status. Several studies, mostly conducted in high latitudes, have shown an association between type 1 diabetes mellitus (T1DM) and low serum 25OHD. We conducted a case–control study to determine whether, in a sub‐tropical environment with abundant sunlight (latitude 27.5°S), children with T1DM have lower serum vitamin D than children without diabetes. Fifty‐six children with T1DM (14 newly diagnosed) and 46 unrelated control children participated in the study. Serum 25OHD, 1,25‐dihydroxy vitamin D (1,25(OH)₂D) and selected biochemical indices were measured. Vitamin D receptor (VDR) polymorphisms Taq1, Fok1, and Apa1 were genotyped. Fitzpatrick skin classification, self‐reported daily hours of outdoor exposure, and mean UV index over the 35 d prior to blood collection were recorded. Serum 25OHD was lower in children with T1DM (n = 56) than in controls (n = 46) [mean (95%CI) = 78.7 (71.8–85.6) nmol/L vs. 91.4 (83.5–98.7) nmol/L, p = 0.02]. T1DM children had lower self‐reported outdoor exposure and mean UV exposure, but no significant difference in distribution of VDR polymorphisms. 25OHD remained lower in children with T1DM after covariate adjustment. Children newly diagnosed with T1DM had lower 1,25(OH)₂D [median (IQR) = 89 (68–122) pmol/L] than controls [121 (108–159) pmol/L, p = 0.03], or children with established diabetes [137 (113–153) pmol/L, p = 0.01]. Children with T1DM have lower 25OHD than controls, even in an environment of abundant sunlight. Whether low vitamin D is a risk factor or consequence of T1DM is unknown.     

Determinants of Serum Vitamin D Levels in Preadolescent Cystic Fibrosis Children

ABSTRACT. The effects of liver disease, fat malabsorption and sunlight exposure on serum vitamin D levels were determined in 21 optimally treated preadolescent cystic fibrosis (CF) children over a 12-month period. Manifest liver disease and fat malabsorption appeared not to affect the vitamin D level. However, the level fell significantly in winter, although not below the normal range, suggesting that sunlight exposure is a more important determinant of vitamin D levels in preadolescent CF children than liver disease and fat malabsorption.     

Dental caries and vitamin D status in children in Asia

Dental caries and vitamin D inadequacy are known to affect children worldwide. Vitamin D has a vital role in tooth formation. There is growing evidence linking suboptimal serum vitamin D level with dental caries in children. This paper reviews the literature on both the prevalence of dental caries and of vitamin D deficiency in children in four Asian regions, discusses their associated risk factors, and reviews the global evidence on the association between dental caries and vitamin D in children. Caries prevalence in children ranged from 40% to 97% in Eastern Asia, 38–73.7% in Southern Asia, and 26.5–74.7% in Western Asian countries. Moreover, a higher prevalence of vitamin D deficiency in Asian children was identified, even in countries in equatorial regions, ranging from 2.8% to 65.3% in Eastern Asia, 5–66.7% in Southern Asia, 4–45.5% in Western Asia and 38.1–78.7% in Central Asian countries. Obesity, age, female gender, higher latitude, season, darker skin pigmentation, sunlight protection behaviors, less sunlight exposure and low intake of food containing vitamin D were important factors associated with lower serum vitamin D in Asia. Suboptimal vitamin D level in children may be a significant risk factor for dental caries, and requires further research to ascertain such an association in children in Asia, as well as to understand its exact influence on caries risk and development.     

Etiology of rickets in India

Nutritional rickets is not rare among Indian children. The involvement of several protein components in the metabolism and function of vitamin D suggests that protein nutrition may influence the final expression of its biological activity. Experiments in rats maintained on rachitogenic/diet showed that administration of vitamin D or its metabolites elicited for better response in those fed on low protein (5%) than on adequate protein (18%). The vitamin D metabolism was found to be similar in both the groups. The super responsiveness to vitamin D or its metabolites in rats fed on low protein diet was due to increased receptor concentration in the intestine. Clinical studies indicated that the metabolism and function of vitamin D and also vitamin D binding protein concentration were not altered in malnourished children with or without rickets. Serum 25-hydroxy vitamin D levels were found to be reduced in malnourished children without rickets as compared to normal children. Inadequate exposure to sunlight appears to be mainly responsible for rickets in children. In addition, malnutrition perhaps contributes to the development of the disease.     

Heightened attention to supplementation is needed to improve the vitamin D status of breastfeeding mothers and infants when sunshine exposure is restricted

Although exclusively breastfed infants are at increased risk of vitamin D (vit D) deficiency if vit D supplementation is lacking and sun exposure is limited, assessment of both risk factors in the first year of life is lacking. We evaluated the contribution of vit D intake and sunlight exposure to vit D status in 120 healthy, breastfeeding mother–infant dyads, who were followed up for 1 year. Vitamin D intake and skin sunlight exposure were evaluated using questionnaires. Serum 25‐hydroxyvitamin D, parathyroid hormone (PTH) and alkaline phosphatase levels were determined post‐natally in mothers at 4 weeks and in infants at 4, 26 and 52 weeks. Vitamin D supplementation was low (<20%) and sunlight exposure was common (93%) in study infants. At 4 weeks, 17% of mothers were vit D deficient (<50 nmol L^?1) and 49% were insufficient (50–<75 nmol L^?1), while 18% of infants were severely vit D deficient (<25 nmol L^?1) and 77% were deficient (<50 nmol L^?1). At 26 weeks, winter/spring birth season and shorter duration of months of exclusive breastfeeding were protective of vit D deficiency in infants. Vitamin D deficiency in infants decreased to 12% at 52 weeks with sunlight exposure. Serum PTH levels were significantly higher in severely vit D deficient than sufficient infants. Vitamin D deficiency was widespread in early post‐partum breastfeeding mothers and infants, and declined to one in eight infants at 52 weeks due mostly to sunshine exposure. When sunlight exposure is limited or restricted, intensified vit D supplementation of breastfeeding mothers and infants is needed to improve vit D status.     

Effect of combined maternal and infant vitamin D supplementation on vitamin D status of exclusively breastfed infants

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.     

Validity of a self‐administered diet history questionnaire for estimating vitamin D intakes of Japanese pregnant women

Maternal vitamin D status is important for fetal development and the prevention of pregnancy complications. Mothers require both sufficient intakes and skin production of this vitamin. We investigated the validity and test–retest reliability of a self‐administered diet history questionnaire (DHQ) to establish a method of assessing vitamin D intakes of Japanese pregnant women, using a serum marker. A total of 245 healthy pregnant women in the second trimester, who were not taking vitamin D supplements, were recruited at a university hospital in Tokyo between June 2010 and July 2011. Serum 25‐hydroxyvitamin D [25(OH)D] concentrations were measured as an indicator of vitamin D status. To assess the test–retest reliability of the DHQ, 58 pregnant women completed it twice within a 4–5‐week interval. Significant positive correlations between intakes and serum concentrations of vitamin D were found (r = 0.266 for daily intakes and r = 0.249 for energy‐adjusted intakes). In the winter investigation in which the serum 25(OH)D concentrations were less likely to be affected by sunlight exposure, the correlation coefficients were 0.304 for both daily and energy‐adjusted intakes. After excluding participants with pregnancy‐associated nausea, the coefficients increased. The intraclass correlation coefficient between vitamin D intakes estimated from the two‐time DHQ was 0.638. The DHQ provides an acceptable validity and reliability of the vitamin D intake of Japanese pregnant women. However, the data of women with nausea should be interpreted with caution. We believe that the DHQ is a useful questionnaire to grasp and improve vitamin D intakes during pregnancy.     

Prevalence and risk factors of vitamin D deficiency rickets in Hokkaido, Japan

Background:  Resurgence of vitamin D deficiency rickets has been recognized worldwide. While many cases of this disease have been reported in Hokkaido, the northern island of Japan, no prevalence data is available. Here, we investigated the prevalence and risk factors of vitamin D deficiency rickets in Hokkaido.
Methods:  A specially designed questionnaire was sent to 84 major pediatric departments of hospitals in Hokkaido to collect information of the confirmed cases between July 1999 and June 2004.
Results:  Sixty-seven hospitals responded to the questionnaire. Of these, 20 hospitals reported 31 confirmed cases. All the patients were infants and toddlers, less than 4 years of age. The prevalence of cases in a recent year was estimated to be nine in 100 000 children under four years of age. Most of the 31 cases in our study were breast-fed. Eleven cases showed signs of malnutrition due to unbalanced diet or dietary restriction. Furthermore, the prevalence of cases was higher in the northeastern region than in the southwestern region. The number of cases increased gradually from the end of winter to spring.
Conclusions:  This is the first report ascertaining the prevalence of vitamin D deficiency rickets in Hokkaido, Japan. Limited exposure to sunlight and inadequate diet in early childhood are key risk factors of this disease. Thus, it is crucial to introduce active recommendations for vitamin D supplementation based on age, residential area, and to advocate public awareness for preventing this disease.     

维生素D缺乏、钙缺乏对雏鸡长骨生长板软骨发育的影响

目的 钙和维生素Ｄ（ＶｉｔＤ）是影响骨发育的两个重要因素，通过建立雏鸡单纯钙缺乏、ＶｉｔＤ缺乏的动物模型，比较两种情况下肥大软骨细胞凋亡的变化。方法 该研究在建立不同发育阶段单纯ＶｉｔＤ、钙缺乏肉鸡雏动物模型的基础上，采用Ｔｕｎｅｌ原位末端标记检测技术、流式细胞术等方法，从形态、生化及组织学等多方面对ＶｉｔＤ缺乏、钙缺乏所致骨生长发育障碍的机制进行了深入的研究。结果 正常软骨细胞凋亡发生在终末肥大