新生儿维生素D水平与孕母维生素D水平的关系

目的 探讨新生儿维生素D 水平与孕母维生素D 水平的相关性。方法 2015 年6 月1 日至7月10 日采集102 名足月单胎新生儿脐静脉血及其孕母静脉血,采用同位素稀释超高效液相色谱串联质谱法测定血清25(OH)D 水平。结果 孕母维生素D 不足者39 例(38.2%),缺乏者25 例(24.5%)。新生儿维生素D 不足者27 例(26.5%),缺乏者66 例(64.7%)。不同血清25(OH)D 水平孕母组新生儿25(OH)D 水平差异有统计学意义(P<0.001)。孕母25(OH)D 水平与新生儿维生素D 水平呈正相关(r=0.914,P<0.001)。孕母25(OH)DROC 曲线预测新生儿维生素D 缺乏(≤ 15 ng/mL)的曲线下面积为0.962,95%CI: 0.930~0.994,P<0.001。孕母血清25(OH)D ≤ 27.55 ng/mL 为界值预测新生儿维生素D 缺乏的灵敏度为97.2%,特异度为80.3%。结论 新生儿维生素D 水平与孕母维生素D 水平正相关;孕母维生素D 水平可预测新生儿维生素D 缺乏。     

婴幼儿常见下呼吸道感染性疾病与淋巴细胞亚群变化关系的研究

目的 探讨淋巴细胞亚群在儿童常见下呼吸道感染支气管炎、支气管肺炎和毛细支气管炎中的变化及临床意义。方法 选取111 例支气管炎、418 例支气管肺炎和83 例毛细支气管炎患儿为疾病组,同期健康婴幼儿235 例为对照组,用流式细胞仪检测各组淋巴细胞亚群。结果 支气管炎组总T 淋巴细胞、CD3⁺CD8⁺细胞低于对照组(P<0.05)。支气管肺炎组总T 淋巴细胞和CD3⁺CD8⁺ 细胞低于对照组、Th 和CD4/CD8 高于对照组,且Th 比例高于支气管炎组;与轻症肺炎组相比,重症肺炎组总T 淋巴细胞降低而B 淋巴细胞升高(P<0.05)。毛细支气管炎组Th 细胞和CD4/CD8 高于对照组、CD3⁺CD8⁺ 细胞低于对照组(P<0.01)。与对照组比,3 组下呼吸道感染患儿的B 淋巴细胞增高、NK 细胞比例降低(P<0.05)。结论 细胞免疫功能紊乱或低下以及体液免疫功能亢进参与了婴幼儿下呼吸道感染的发生和发展,并且变化程度与疾病类型及病情程度有关。     

肺炎心衰时脑钠素改变及其与心功能关系的临床与实验研究

目的 探讨重症肺炎时血清脑钠素(BNP)的变化及其与心脏收缩功能的关系。方法 对2002年8月至2004年4月在山东省立医院确诊的70例肺炎患儿及20例正常健康儿行超声心动图检查,同时将50只大鼠制成肺炎大鼠30只和正常大鼠20只,也行上述检查;采用酶联免疫吸附法检测上述各组BNP水平。结果 肺炎心衰组患儿及左室射血分数(LVEF)下降大鼠组血清BNP水平显著高于健康对照组及正常大鼠对照组,且与LVEF、左室短轴缩短率(LVFS)呈负相关(P<0.05);肺炎心衰组患儿与健康组患儿比较,LVEF下降大鼠与正常大鼠比较,主动脉血流峰值流速(PFVA)、肺动脉血流峰值流速(PFVP)、主动脉血流速度积分(Viao)、肺动脉血流速度积分(Vipa)、LVEF、LVFS显著减少(P<0.05)。结论 严重肺炎可引起心衰,血清BNP测定可作为诊断心功能不全的生化指标。     

抽动障碍患儿血清25羟基维生素D水平的检测

目的了解抽动障碍(TD)患儿维生素D的营养状况,探讨维生素D水平与TD的关系。方法选取2016年11月至2017年5月诊断为TD的132例患儿为TD组,其中抽动秽语综合征患儿8例,慢性运动或发声抽动障碍患儿32例,暂时性抽动障碍患儿92例;另选取同期行体检的健康儿童144例为健康对照组。采集两组儿童外周静脉血3 m L,留取血清,采用高效液相色谱-串联质谱法检测两组儿童血清25羟基维生素D[25(OH)D]水平,根据血清25(OH)D水平,30 ng/m L为正常、10~30 ng/m L为不足、10 ng/m L为缺乏。结果 TD患儿血清25(OH)D水平明显低于健康对照组(P0.01);TD患儿血清25(OH)D不足或缺乏率明显高于健康对照组(P0.01);暂时性抽动障碍患儿血清25(OH)D水平高于抽动秽语综合征患儿(P0.05)。结论维生素D缺乏或不足可能是导致TD发病的因素之一;且维生素D水平高低可能与TD分型存在关联。     

Th17/Treg细胞比例失衡在儿童原发性免疫性血小板减少症中的意义

目的 探讨Th17/Treg 细胞比例失衡在儿童原发性免疫性血小板减少症(ITP)发病及治疗中的意义。方法 选取2015 年5 月至2015 年8 月确诊为ITP 的32 例患儿作为ITP 组,同期选取22 例健康儿童作为健康对照组,采用流式细胞术分别检测初诊ITP 患儿、丙种球蛋白治疗后的ITP 患儿和健康对照组儿童外周血Th17、Treg 细胞的比例。结果 ITP 患儿治疗前外周血Th17 占CD4⁺T 细胞的比例、Th17/Treg 细胞比值均显著高于治疗后及健康对照组儿童(P<0.05),治疗前Treg 细胞占CD4⁺T 细胞的比例显著低于治疗后及健康对照组儿童(P<0.05);32 例ITP 患儿经治疗后,20 例完全反应,4 例有效,8 例无效,完全反应患儿外周血Th17细胞占CD4⁺T 细胞比例、Th17/Treg 细胞比值显著低于无效患儿(P<0.05)。结论 儿童ITP 中存在Th17/Treg细胞比例失衡,丙种球蛋白可通过调节Th17/Treg 细胞比例变化进而改变患儿细胞免疫功能,治疗过程中检测该比值变化可能对疾病的疗效有一定的预测作用。     

肥胖对哮喘儿童治疗效果及肺功能的影响

目的 探讨肥胖对哮喘患儿规范化吸入疗法疗效及肺功能的影响。方法 129 例哮喘患儿分为正常体重哮喘组(n=64)和哮喘伴肥胖组(n=65),比较两组患儿接受规范化吸入治疗1 年后的肺功能和哮喘控制情况,其中肺功能采用第1 秒用力呼气容积占预计值的百分比(FEV1%)、用力肺活量占预计值百分比(FVC%)、呼气峰流速(PEF)、用力呼气25% 流速(PEF₂₅)、用力呼气50% 流速(PEF₅₀)表示。另选取68 例健康儿童作为健康对照组。结果 治疗前3 组间肺功能各指标比较差异均有统计学意义(P<0.01),其中健康对照组肺功能测定值最优,哮喘伴肥胖组测定值最差。治疗1 年后正常体重哮喘组FEV1%、FVC% 的改善均明显优于哮喘伴肥胖组(P<0.01),但两组间PEF、PEF₂₅、PEF₅₀ 的改善差异无统计学意义 。治疗1 年后,正常体重哮喘组哮喘完全控制率、部分控制率、未控制率分别为72%、19%、9%; 哮喘伴肥胖组完全控制率、部分控制率、未控制率分别为28%、51%、22%,正常体重哮喘组哮喘控制率优于哮喘伴肥胖组(P<0.01)。结论 哮喘伴肥胖患儿治疗后大气道功能改善及哮喘控制状况较正常体重哮喘患儿差。     

注意缺陷多动障碍患儿血清25羟基维生素D水平的检测

目的 了解注意缺陷多动障碍(ADHD)患儿维生素D的营养状况,探讨维生素D与ADHD的关系。方法 选取2014年 1月至2015年 1月符合美国精神障碍诊断与统计手册第五版(DSM-V)中ADHD诊断、分型标准的97例ADHD患儿为病例组,其中注意缺陷为主型(ADHD-I型)46例,多动冲动为主型(ADHD-HI型)10例,混合型(ADHD-C型)41例,以同期同年龄行健康体检儿童97例作为对照组。采用电化学发光法对ADHD组和对照组儿童血清中25羟基维生素D[25(OH)D]水平进行检测,比较两组儿童25(OH)D水平的差异。结果 ADHD组患儿血清25(OH)D水平(17±7 ng/mL)明显低于对照组(23±8 ng/mL)(P< 0.01);且各亚型ADHD患儿25(OH)D水平均明显低于对照组(P< 0.05)。ADHD组患儿25(OH)D水平正常、不足及缺乏的比例分布情况与对照组比较差异有统计学意义(P< 0.01);且各亚型ADHD患儿25(OH)D水平的分布情况与对照组比较差异均有统计学意义(P< 0.05)。结论 ADHD患儿25(OH)D水平明显低于健康儿童,25(OH)D水平与ADHD可能存在一定的相关性。     

苏州地区14994例儿童呼吸道感染细菌病原学特点

目的 了解儿童呼吸道感染的细菌病原学特点。方法 收集2005 年11 月至2014 年10 月连续9 年因呼吸道感染入住苏州大学附属儿童医院的14 994 例儿童的病例资料进行回顾性分析。结果 14 994 份呼吸道感染患儿的痰标本中,细菌培养阳性3 947 份,总阳性检出率为26.32%。第1 位细菌病原为肺炎链球菌(12.79%),其次为流感嗜血杆菌(5.02%)、卡他莫拉菌(2.91%)。在不同年份、不同季节、不同年龄段儿童细菌检出率差异有统计学意义(P<0.01)。入院前未使用过抗菌药物的患儿痰细菌培养阳性率高于使用过抗菌药物的患儿(P<0.01)。院外病程<1 个月组、1~3 个月组及>3 个月组患儿痰培养细菌检出率差异有统计学意义(P<0.05)。肺炎链球菌、卡他莫拉菌、鲍曼不动杆菌的阳性检出率随病程的延长呈上升趋势(P<0.05)。结论 肺炎链球菌是引起儿童呼吸道感染的最常见细菌病原,其次为流感嗜血杆菌和卡他莫拉菌。各种细菌在不同的年份、不同的季节、不同的年龄阳性检出率有差异。疾病病程与院外抗菌药物使用对细菌的阳性检出率有影响。     

孤独症谱系障碍患儿血清25(OH)D水平的检测

目的了解孤独症谱系障碍(ASD)患儿维生素D营养状况,探讨维生素D水平与ASD的关系。方法采用高效液相色谱-串联质谱法对117例新诊断的ASD患儿和109例健康对照儿童进行血清25(OH)D检测,并根据血清25(OH)D水平,将维生素D状况分为正常(30 ng/m L)、不足(10~30 ng/m L)和缺乏(10 ng/m L),比较两组儿童维生素D营养状况。结果 ASD患儿25(OH)D水平(19±9 ng/m L)明显低于对照组(36±13 ng/m L),差异有统计学意义(P0.01)。ASD患儿中维生素D缺乏和不足率为89.7%,明显高于对照组(52.3%),差异有统计学意义(P0.01)。结论 ASD患儿存在维生素D缺乏或不足,维生素D缺乏和不足有可能是ASD发病的环境/遗传因素。     

儿童急性淋巴细胞白血病中性粒细胞缺乏伴发热单中心血流感染病原菌分析

目的 分析儿童急性淋巴细胞白血病(ALL)化疗后中性粒细胞缺乏伴发热(FN)血流感染的临床特点、危险因素和病原菌分布。方法 回顾性分析2007年1月1日至2016年12月31日上海交通大学附属儿童医院血液肿瘤科收治的ALL化疗后发生FN住院患儿的临床资料和血培养结果,分析菌株的分布及药敏特点。结果 纳入ALL患儿312例,FN1 548例次,共送检1 700例次血培养,血培养阳性率7.5%(127/1 700),血流感染发生率8.2%(127/1 548),病死率9.4%(12/127)。血流感染革兰阳性菌51.1%(65/127),革兰阴性菌47.2%(60/127),真菌1.5%(2/127)。革兰阴性菌血流感染与革兰阳性菌血流感染比较,ANC<0.1×10⁹·L^-1的患儿占比(P=0.041)和感染性休克发生率更高(P=0.002)。2012~2016年铜绿假单胞菌构成比较2007~2011年增加(χ²=4.712,P=0.030)。ALL的危险程度分层IR/HR(OR=2.560,P=0.045)和ANC<0.1×10⁹·L^-1(OR=0.754,P=0.025)是血流感染发生的独立危险因素。结论 ALL患儿发生FN时血流感染病原菌阳性率较高(8.2%),以革兰阳性菌感染为主。在严重粒细胞缺乏时以革兰阴性菌血流感染为主,铜绿假单胞菌感染有增加趋势,合并感染性休克是FN死亡的独立危险因素。     

Sociodemographic and clinical characteristics associated with vitamin D status in newly diagnosed pediatric cancer patients

Abstract

Vitamin D deficiency and insufficiency are associated with serious sequelae in childhood cancer survivors. However, data on vitamin D deficiency in children with newly diagnosed cancer are scarce and the role of sociodemographic factors and vitamin D supplementation is largely unknown. We assessed vitamin D status and its socio-demographic and clinical correlates in 163 children with newly diagnosed cancer, using 25-hydroxy vitamin D (25(OH)D) concentrations and assessed longitudinal changes following vitamin D supplementation. Sixty-five percent of the patients with newly diagnosed cancer had low 25(OH)D concentrations. Fifty-two patients (32%) were vitamin D deficient (≤20?ng/mL 25(OH)D concentration), and 53(33%) were insufficient (21-29?ng/mL 25(OH)D concentration). Age over 10 (P?=?0.019), Hispanic ethnicity (P?=?0.002), and female sex (P?=?0.008) were significantly associated with lower 25(OH)D concentration at diagnosis. Vitamin D supplementation resulted in significant increase in 25(OH)D concentrations (P?<?0.001). However, following supplementation in the longitudinal analysis, this increase was less pronounced in Hispanic patients vs. non-Hispanic (P?=?0.007), and in children with solid tumors vs. hematological malignancies (P?=?0.003). Vitamin D deficiency and insufficiency are common in children with newly diagnosed cancer. Hispanic patients, females and older children were at higher risk for vitamin D deficiency and insufficiency. Although supplementation appeared to increase 25(OH)D concentrations over time, this increase was not as pronounced in certain subsets of patients. Prospective trials of the effects of vitamin D supplementation on bone health in children with newly diagnosed cancer are warranted, particularly in Hispanics and patients with solid tumors.     

4~12岁哮喘儿童维生素D水平与哮喘控制及肺功能的关系

目的 探讨哮喘儿童血清维生素D水平与哮喘控制及肺功能的关系。方法 纳入150例哮喘患儿为观察组,55例健康儿童为对照组。按哮喘控制水平分级标准将观察组分为良好控制组、部分控制组和未控制组。采用化学发光微粒子免疫检测法检测各组血清25羟维生素D[25（OH）D]水平。根据25（OH）D的水平将哮喘儿童分为维生素D正常组、维生素D不足组和维生素D缺乏组,并对哮喘儿童进行肺功能测定。结果 观察组血清25（OH）D水平显著低于对照组（25±7 ng/mL vs 29±4 ng/mL,P < 0.05）。维生素D正常组、维生素D不足组、维生素D缺乏组哮喘控制率依次降低（P < 0.05）,但3组肺功能的比较差异无统计学意义（P > 0.05）。结论 哮喘儿童血清25（OH）D水平较正常儿童降低,且与哮喘控制水平有关,但与肺功能无相关性。     

维生素D含量与幼年特发性关节炎的关系

目的 25 羟维生素D3 [25(OH)D3] 是维生素D(VitD)的主要产物,可反映体内活性VitD 的绝对含量。该文检测了幼年特发性关节炎(JIA)患儿血清25 羟维生素D3 [25(OH)D3] 水平的变化,以了解VitD 含量与JIA 发病、疾病活动度等的可能关系。方法 收集2013 年1 月至2014 年3 月确诊为JIA 的53 例患儿的血清标本,采用酶联免疫法检测其血清25(OH)D3 水平,并与同期106 例正常体检儿童(对照组)血清25(OH)D3水平作比较。并分析JIA 患儿25(OH)D3 水平与JIA 亚型、疾病活动度、外周血超敏C 反应蛋白、血沉的相关性。结果 与对照组比较,JIA 组25(OH)D3 水平明显减低(中位数42.6 nmol/L vs 49.9 nmol/L,P<0.01)。JIA 组VitD 严重缺乏比例明显高于对照组(17.0% vs 6.6%,P<0.05)。JIA 患儿血清25(OH)D3 水平与JIA 亚型、疾病活动度、C 反应蛋白、血沉无明显相关性。结论 JIA 儿童VitD 含量明显减低,VitD 含量降低可能与JIA 的发生有关,但VitD 含量与JIA 亚型、疾病严重度及活动性无关。     

Impact of season and diet on vitamin D status of African American and Caucasian children

Seasonal variation of vitamin D status and adequacy of dietary vitamin D and impact of race on maintaining vitamin D sufficiency was assessed in 140 healthy 6- to 12-year-old African American (AA) and Caucasian (C) children residing in Pittsburgh, Pennsylvania during summer and winter. Vitamin D insufficiency was not rare in either group (AA vs C, summer, 17.2% vs 14.3%, nonsignificant; winter, 34.1% vs 32.5%, nonsignificant) despite a mean dietary intake of vitamin D above the American Academy of Pediatrics (AAP) recommended intake (400 IU/d; AA vs C, summer, 421 vs 456 IU/d, nonsignificant; winter, 507 vs 432 IU/d, nonsignificant). Race/season and dietary vitamin D were predictors of serum 25-hydroxyvitamin D [25(OH)D] concentrations. However, dietary vitamin D influenced 25(OH)D only in Caucasians during winter. Current AAP recommended daily intake for vitamin D is inadequate for maintaining vitamin D sufficiency in children.     

Prevalence of vitamin D insufficiency among healthy school-age Cree children

BACKGROUND:

First Nations children are at higher risk for vitamin D deficiency and rickets.

OBJECTIVE:

To assess the prevalence of vitamin D deficiency and the correlations between fat mass, parathyroid hormone and dietary habits with serum vitamin D level in a random sample of Cree children eight to 14 years of age.

METHODS:

Serum 25-hydroxyvitamin D (25[OH]D) levels and additional information regarding anthropometrics and dietary habits were obtained from participants in two Cree communities. Vitamin D deficiency and insufficiency was defined as serum 25(OH)D levels <30 nmol/L and <50 nmol/L, respectively. Proportions to estimate the vitamin D status were weighted to account for the complex sampling design, and Pearson’s correlation coefficients were used to estimate the associations of milk and fish intake, parathyroid hormone and fat mass with serum 25(OH)D levels.

RESULTS:

Data from 52 healthy Cree children (mean [± SD] age 11.1±2.0 years; 27 boys) were included in the analyses. The median serum 25(OH)D level was 52.4 nmol/L (range 22.1 nmol/L to 102.7 nmol/L). Forty-three percent (95% CI 29% to 58%) and 81% (95% CI 70% to 92%) of Cree children had vitamin D levels <50 nmol/L and <75 nmol/L, respectively. Vitamin D intake was positively associated with serum 25(OH)D levels. Obese children had lower vitamin D levels; however, the difference was nonsignificant.

CONCLUSION:

There may be a substantial proportion of Cree children who are vitamin D deficient. Increasing age, lower dietary vitamin D intake and, possibly, higher body mass index were associated with decreased vitamin D levels; however, causality cannot be inferred.     

Serum vitamin D concentrations and associated severity of acute lower respiratory tract infections in Japanese hospitalized children

Background: Vitamin D is an immunomodulatory molecule related to innate immunity that may contribute to the increased occurrence of acute lower respiratory infection (ALRI) in children, one of the most common reasons for hospitalization and intensive care unit admission. In the present study, the association between vitamin D deficiency and the severity of respiratory infection was evaluated by determining serum concentrations of 25‐hydroxyvitamin D (25(OH)D) in a group of hospitalized children with ALRI. Methods: Of the 28 children admitted to Nihon University Nerima‐Hikarigaoka Hospital with ALRI over the period November 2008–May 2009, 26 were diagnosed as having bronchiolitis and two were found to have pneumonia. A competitive protein binding radioimmunoassay was used to determine serum 25(OH)D concentrations. Results: Mean 25(OH)D concentrations in breast‐fed children with ALRI (n = 7) were significantly lower than those in children with ALRI who were bottle fed/weaned (n = 6) or on a regular diet (n = 15; 14.6 ± 9.7, 28.9 ± 6.9 and 24.6 ± 8.8 ng/mL, respectively). There was a significant correlation between vitamin D deficiency (<15 ng/mL) and the need for supplementary oxygen and ventilator management. Conclusion: Significantly more children with ALRI who needed supplementary oxygen and ventilator management were vitamin D deficient. These findings suggest that the immunomodulatory properties of vitamin D may influence the severity of ALRI.     

Vitamin D status in Norwegian children and adolescents with excess body weight

Lagunova Z, Porojnicu AC, Lindberg FA, Aksnes L, Moan J. Vitamin D status in Norwegian children and adolescents with excess body weight. Objectives: The prevalence of childhood and adolescent obesity has increased during the past decades. A high body mass index (BMI) is associated with a low vitamin D status. The purpose of this study was to determine the prevalence of vitamin D deficiency and insufficiency in Norwegian children and adolescents with excess body weight. Methods: Vitamin D status and seasonal variations of 25(OH)D and 1,25(OH)₂D were analyzed in 102 children and adolescents (70 girls and 32 boys), 8–19 yr of age, with overweight and obesity. Results: Overall, 50% of the children and adolescents included in the study had a low vitamin D status (25(OH)D <75 nmol/L) and 19% had vitamin D deficiency (25(OH)D <50 nmol/L). This was most prevalent in adolescents. Only 42% of teenagers had 25(OH)D levels ≥75 nmol/L vs. 72% of preteens. Both 25(OH)D and 1,25(OH)₂D showed seasonal variations. A peak in serum 25(OH)D concentrations was observed during the summer while the lowest values were seen during the spring. In contrast, serum 1,25(OH)₂D had a peak during the spring and the lowest concentrations during the winter. Conclusions: The prevalence of vitamin D deficiency and insufficiency is higher in obese and overweight adolescents than in overweight children. This might be related to low outdoor activities and low vitamin D intake in teenagers. Seasonal variations of both the vitamin D metabolites were observed.     

Vitamin D deficiency and its relationship with cardiac iron and function in patients with transfusion-dependent thalassemia at Chiang Mai University Hospital

Background: Vitamin D deficiency is common in patients with thalassemia. Vitamin D deficiency could be related to cardiac dysfunction. Increased parathyroid hormone (PTH) is also known to be associated with heart failure. Objectives: To determine the prevalence of Vitamin D deficiency and to explore the impact of Vitamin D deficiency on cardiac iron and function in patients with transfusion-dependent thalassemia. Method: A cross-sectional study in patients with Transfusion-dependent thalassemia was conducted. Patients with liver disease, renal disease, type 1 diabetes, malabsorption, hypercortisolism, malignancy, and contraindication for MRI were excluded. Calcium, phosphate, PTH, vitamin D-25OH were measured. CardiacT2^* and liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) were determined. Results Sixty-one (33M/28F) patients with Transfusion-dependent thalassemia were enrolled. The prevalence of Vitamin D deficiency was 50.8%. Patients with cardiac siderosis had tendency for lower D-25OH than those without siderosis (15.9 (11.7–20.0) vs. 20.2 (15.85–22.3) ng/mL); p = 0.06). Serum calcium, phosphate, PTH, LIC, cardiac T2^*, and LVEF were not different between the groups with or without Vitamin D deficiency. Patients with Vitamin D deficiency had significantly lower hemoglobin levels compared to those without Vitamin D deficiency (7.5 (6.93–8.33) vs. 8.1 (7.30–8.50) g/dL; p = 0.04). The median hemoglobin in the last 12 months was significantly correlated with D-25OH. Cardiac T2^* had significant correlation with PTH. Conclusion: Vitamin D deficiency is prevalent in patients with Transfusion-dependent thalassemia. Vitamin D level is correlated with hemoglobin level. Vitamin D status should be routinely assessed in these patients. Low PTH is correlated with increased cardiac iron. This study did not demonstrate an association between Vitamin D deficiency and cardiac iron or function in patients with Transfusion-dependent thalassemia.     

Optimal level of 25‐(OH)D in children in Nanjing (32°N Lat) during winter

Background: The optimal serum level of 25‐hydroxyvitamin D (25‐(OH)D) for bone health is still unclear, especially in children. Hypovitaminosis D is also re‐emerging in developed and developing countries. The purpose of the present study was therefore to determine optimal serum 25‐(OH)D level and preliminarily identify the vitamin D nutritional status in Nanjing children. Methods: All subjects (76 healthy, 66 suffering from infectious diseases) aged 0–10 years were recruited during the period December 2007–March 2008. Venous blood samples were collected before breakfast and the levels of serum 25‐(OH)D, parathyroid hormone (PTH), bone‐specific alkaline phosphatase (BAP), calcium (Ca), phosphorus (P) were determined. The optimal level of serum 25‐(OH)D was explored using the three response curves of 25‐(OH)D versus PTH, 25‐(OH)D versus BAP, and 25‐(OH)D versus Ca×P product. Results: For 25‐(OH)D ≤ 50 nmol/L, PTH and BAP were both inversely correlated with 25‐(OH)D (PTH, r=?0.864, P < 0.01; BAP, r=?0.856, P < 0.01). For 25‐(OH)D > 50–60 nmol/L, levels of PTH and BAP remained steady. With regard to the Ca×P product, for 25‐(OH)D ≤ 50 nmol/L, Ca×P product increased as 25‐(OH)D increased (r= 0.037, P > 0.05). For 25‐(OH)D > 50–60 nmol/L, Ca×P product remained steady. The mean serum level of 25‐(OH)D was 80.5 ± 29.3 nmol/L (mean ± SD) in the healthy children, and 65.7 ± 32.3 nmol/L in the sick children. Conclusion: The optimal 25‐(OH)D level may be 50–60 nmol/L for bone health in Nanjing children. The vitamin D nutritional status of Nanjing children is relatively good in winter.