Vitamin D deficiency rickets at birth in Kuwait

In the present study vitamin D deficiency rickets has been diagnosed within 24 hrs. of birth. Seventy five full term, otherwise healthy newborns, weighing more than 2.5 kg were born with rachitic rosary. 25-Hydroxyvitamin D was lower than normal in 56 newborns and 15 mothers. Alkaline phosphatase was higher than normal in 26 and radiological changes suggestive of rickets were seen in the wrist X ray of only 14 newborns. Hyperphosphataemia was present in all the newborns. 1,25 dihydroxyvitamin D was markedly increased in six out of ten newborns.     

Lymphocyte subpopulations in children with vitamin D deficient rickets

Recent studies have shown 1,25(OH)₂D₃-mediated modulation of the immune system. We examined lymphocyte subpopulations of 16 children with nutritional rickets. Most of the patients suffered more frequent infection episodes than the control group of 15 healthy children and low serum levels of 25OHD and 1,25(OH)₂D, such as 38.2 ± 8.6 ng/mL and 15.7 ± 2.6 pg/mL respectively. This decrease correlated with a significant decrease in total T lymphocytes and an increase in B lymphocytes expressing surface IgA, IgM, IgG molecules. These results suggest that vitamin D plays an important role in the impaired functions of T lymphocytes which may lead to frequent infection episodes in nutritional rickets.     

Parathyroid hormone,calcitonin and vitamin D metabolites in beta-thalassaemia major

Serum calcium (Ca), phosphorus (P), alkaline phosphatase (Al-P), parathyroid hormone (PTH), calcitonin (CT), 25-hydroxyvitamin D₃ (25OHD₃), 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) levels and urinary excretion of Ca, P, hydroxyproline (OH-P) and cyclic AMP (cAMP) were determined in summer and in winter in 13 thalassaemic children (7 aged 3–5 years-group 1-; and 6 aged 10–13 years-group 2-), who had never taken vitamin D supplements or therapy, and in two groups of 14 controls of the same age.In thalassacmics of group 1 only serum AL-P levels and OH-P urinary excretion were higher than in controls (P<0.01). In thalassaemics of group 2 Ca (P<0.05), P (P<0.05), PTH (P<0.001), CT (P<0.001), 25 OHD₃ (P<0.05), 1,25(OH)₂D₃ (P<0.001) levels and cAMP urinary excretion (P<0.001) were lower, whereas Al-P (P<0.001) and CT (P<0.001) levels and urinary excretion of P (P<0.05) and of OH-P (P<0.001) were higher than in controls, both in summer and in winter.Advancing age induces in thalassaemic patients a decrease in PTH secretion and a consequent deficit in synthesis of 1,25(OH)₂D₃ that may explain some aspects of bone changes, which CT hypersecretion may tend to counteract.Abbreviations Ca calcium - P phosphorus - Al-P alkaline phosphatase - PTH parathyroid hormone - CT calcitonin - 250HD₃ 25-hydroxyvitamin D₃ - 1,25(OH)₂D₃ 1,25-dihydroxyvitamin D₃ - OH-P hydroxyproline - cAMP cyclic AMP Presented in part at the 23rd annual meeting of the European Society for Paediatric Endocrinology, Heidelberg, September 2–5, 1984     

Higher prevalence of vitamin D deficiency in mothers of rachitic than nonrachitic children

Vitamin D deficiency [serum 25-hydroxyvitamin D <25 nmol/L (<10 ng/mL)] was identified in 92% of rachitic Arab children and 97% of their mothers compared with 22% of nonrachitic children and 52% of their mothers. There was a positive correlation between maternal and child vitamin D levels. We conclude that mothers of rachitic children should be investigated and treated for vitamin D deficiency.     

Low vitamin D status in children with sickle cell disease

OBJECTIVES: To examine vitamin D status in children with sickle cell disease (SCD)-SS and its relation to season and dietary intake. STUDY DESIGN: Growth, dietary intake, 25-hydroxyvitamin D (25-OHD), and parathyroid hormone levels were measured. Children with low and normal vitamin D status were compared. Low vitamin D status was defined as a serum concentration of 25-OHD <27.5 nmol/L. Serum 25-OHD and parathyroid hormone levels were compared among children with SCD-SS and healthy children. RESULTS: Children with SCD-SS (n=65), 5 to 18 years of age, were evaluated. Mean (+/-SD) serum 25-OHD concentration was 25.5 +/- 12.8 nmol/L; 65% of subjects had low vitamin D status. Low vitamin D prevalence was highest during spring (100%). Children with SCD-SS were at higher risk for low vitamin D status than healthy children. Vitamin D intake was lower in subjects with SCD-SS and low vitamin D than those with normal serum vitamin D status (P <.05). CONCLUSIONS: Low serum vitamin D status was highly prevalent in black children with SCD-SS. Vitamin D status was associated with season and dietary intake.     

中国儿童维生素D、钙营养的流行病学资料

“钙缺乏”一直是我国儿科领域热议的课题,有关钙缺乏、维生素D缺乏性佝偻病等的诊断、治疗等方面也一直争论不休。近期随着欧美国家对人群维生素D缺乏研究的兴起,国内相关报道也明显增加。然而,由于检测血清25-羟维生素D［25-（OH）D］受限及缺少简便、可靠的判断人体钙营养的生物学指标,目前我国总体缺乏有效的流行病学资料以全面了解儿童青少年维生素D、钙营养状况。     

Ultraviolet B radiation improves serum levels of vitamin D in patients with cystic fibrosis

Background: Ultraviolet B (UVB) radiation can be used in the prevention and treatment of vitamin D deficiency. Aim: To investigate, in a controlled study of patients with cystic fibrosis (CF), whether regular UVB radiation would improve serum levels of calcidiol during the dark season (October-April). Methods: Thirty patients with mild to moderate disease were included (aged 9-40 y). All patients had cholecalciferol supplementation. One group (15 patients) was given UVB one to three times a week for 6 mo and one group (15 sex- and age-matched patients) served as controls. The radiation source consisted of three TL 12/40W UVB fluorescent lamps. Initial treatment duration was 1 min, subsequently increased by 0.5-1 min/treatment to a maximum of 10 min. Results: The mean initial serum calcidiol levels were 21 ng/ml in the controls and 22 ng/ml in the intervention group. Serum calcidiol levels increased to 44 ng/ml after 8 wk and to 50 ng/ml after 24 wk of UVB radiation; the corresponding serum levels in the controls were 19 and 25 ng/ml, respectively. The mean serum calcitriol levels increased in the treated group and were unaltered in the control group.

Conclusions: UVB radiation was effective in increasing vitamin D levels in patients with CF. The study results imply that UVB radiation is valuable in chronic conditions associated with vitamin D deficiency.     

Low vitamin D status is associated with low cord blood levels of the immunosuppressive cytokine interleukin-10

The cytokine interleukin-10 (IL-10) plays a pivotal regulatory role in tolerizing exogenous antigens. Experimental data indicate that low cellular availability of the vitamin D hormone 1,25-dihydroxyvitamin D [1,25(OH)2D] results in a down-regulation of IL-10 concentrations. The tissue production of an adequate amount of 1,25(OH)2D depends on a high circulating 25-hydroxyvitamin D (25-OHD) level. The present study was thus aimed at evaluating the associations between season of birth, vitamin D status, and the allergy risk markers IL-10 and total immunoglobulin (IgE) in newborns. Cord blood was obtained from 49 infants born during the summer half year (mid-April to mid-October, geographic latitude 51 degrees N) and from 47 infants born during the winter half year (mid-October to mid-April, geographic latitude of 51 degrees N). Serum levels of 25-OHD were 99% higher, and IL-10 levels were 43% higher in the summer half year compared with the winter half year (p < 0.001 and p = 0.018). Moreover, the ratio of IL-10 to total IgE was 124% higher in the summer half year compared with the winter half year (p = 0.039). Serum levels of 25-OHD were correlated with IL-10 levels (r = +0.22; p < 0.05). Mothers' age, gestational ages, birth weights and serum 1,25(OH)2D levels did not differ between study groups. We conclude that the low vitamin D status of infants born in winter may at least in part adversely affect biomarkers of allergy risk.     

新生儿维生素D营养状况调查

目的通过测定新生儿血清25-羟维生素D[25（OH）D]、甲状旁腺激素（PTH）、钙、磷浓度,了解兰州市新生儿维生素D营养状况,指导临床补充维生素D。方法选取2012年9～12月在兰州大学第一医院住院的90例新生儿为研究对象,早产儿30例,足月儿60例,采用酶联免疫法检测两组患儿生后10天内血清25（OH）D、PTH浓度,并分析两者之间的相关性;血清标本的钙、磷水平由贝克曼AU2700全自动生化分析仪测定。结果早产儿血清25（OH）D浓度为（21．9±2．5）nmol／L,显著低于足月儿（34．9±10．8）nmol／L,差异有统计学意义（P〈0．05）;早产儿血清町H浓度为（94．7±40．2）pg／ml,显著高于足月儿（56．1±30．0）pg／ml,差异有统计学意义（P〈0．05）,新生儿血清25（oH）D水平与明H呈负相关;旱产儿血钙浓度为（2．1±0．3）mmob／L,低于足月儿（2．3±0．3）mmol／L,差异有统计学意义（P〈0．05）;早产儿血磷浓度为（1．8±0．7）mmoL／L,足月儿为（1．6±0．5）mmol／L,差异无统计学意义（P〉0．05）。结论兰州市新生儿普遍存在维生素D缺乏或不足的现象,应加强孕母和新生儿的维生素D补充。     

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??Hypophosphatemic Vitamin D resistant rickets is a group of metabolic bone diseases characterized by increase renal excretion of phosphate and hypophosphatemia. Regulation of phosphate homeostasis includes a complicated feedback network??in which parathyroid hormone??PTH????fibroblast growth factor-23??FGF23?? and 1??25-??OH??D3 are key regulatory factors. With the understanding of phosphate regulation and the pathogenesis of this disease??progresses have been made in the diagnosis and treatment in hypophosphatemic rickets recently. In this review??based on the mechanisms of phosphate regulation??we explain the pathogenesis and clinical manifestations of hypophosphatemic rickets??and summarize up-to-date diagnostic and therapeutic approaches.     

High prevalence of moderately severe vitamin D deficiency in preterm infants

Background: The recommended dose of vitamin D supplementation of preterm infants is based on data from populations in which severe vitamin D deficiency is uncommon and may be inadequate for infants in high risk population. However, data on vitamin D status of preterm infants in high‐risk populations, such as Middle Eastern countries is scarce. Methods: This study investigates the vitamin D status of Arab mothers and their preterm infants. Maternal serum and cord blood 25(OH)D, calcium (Ca), phosphorus (P) and alkaline phosphate (ALP) were measured at delivery. Serum 25(OH)D was measured by HPLC while the other biochemical parameters were measured by standard autoanalyzer. Results: Thirty‐four preterm infants were studied. The mean gestational age was 31.4 weeks and birth weight was 1667 g. The median serum 25(OH)D of 17.0 nmol/L in 28 mothers and 14.5 nmol/L in 34 cord blood samples were low. The median maternal and cord blood Ca, P and ALP levels were within normal range. Fifteen (44%) of the infants had moderately severe vitamin D deficiency (serum 25 (OH)D levels <12.5 nmol/L). The median serum 25(OH)D levels of mothers who had reportedly taken prenatal vitamin D supplementation and those who had not were similar (17.3 vs 16.3) nmol/L. The mean serum 25(OH)D levels among preterm infants in this study were low when compared to levels in Caucasians preterm infants on which the current vitamin D recommendations are based. Conclusion: The high prevalence of moderately severe vitamin D deficiency in Arab preterm infants provides a justification to investigate vitamin D requirement of preterm infants in this and other high‐risk populations.     

石家庄市夏季汉族4月龄至14岁健康儿童血清25-羟维生素D和甲状旁腺素的关系

目的探讨汉族儿童青少年夏季血清25-羟维生素D(25OHD)和甲状旁腺素(PTH)水平的关系,以及儿童青少年是否存在PTH进入平台期的血清25OHD拐点值。方法河北医科大学第二医院儿科生长发育门诊于2011年6~8月及2012年6~8月向社会招募4月龄至14岁健康儿童青少年。分为1岁、~3岁、~6岁、~10岁和~14岁组。分别采用酶联免疫法和化学发光免疫分析法测定血清25OHD和全段PTH水平。对血清25OHD与PTH水平的关系分别行直线、二次多项式、指数和对数拟合等,计算血清PTH水平进入平台期的血清25OHD阈值。结果共招募632名健康儿童青少年,男童372名,女童260名。1血清25OHD和PTH水平的中位数(P25,P75)分别为56.7(42.2,76.4)nmol·L-1和2.5(2.0,3.3)pmol·L-1。2血清25OHD与PTH在除~10岁组外的其余年龄组中均呈负相关。3二次多项式回归方程能较好反映血清25OHD和PTH之间的曲线关系。回归方程为PTH(pmol·L-1)=4.2698-0.0352·25OHD+0.0002·25OHD2,R2=0.0684。PTH进入平台期时血清25OHD的拐点值为88 nmol·L-1,对应的PTH值为2.72 pmol·L-1。结论 4月龄至14岁汉族儿童青少年的血清25OHD和PTH水平呈负相关,且理想的血清25OHD水平可能为88 nmol·L-1。     

佝偻病维生素D受体基因多态性与25-羟维生素D3相关性

目的：研究1~3岁佝偻病患儿中维生素D受体基因多态性FokⅠ位点与佝偻病相关性,初步探讨维生素D受体基因多态性FokⅠ位点在佝偻病发病中的作用。方法：病例组（佝偻病患儿）62例与对照组（正常健康儿童）60例,用ELISA方法检测血清25-羟维生素D3水平,比较两组之间血清25-羟维生素D3水平。用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）检测病例组和对照组维生素D受体基因多态性FokⅠ位点,比较两组之间基因型和等位基因分布频率。结果病例组血清25-羟维生素D3水平较对照组明显降低,差异有统计学意义（9.1±4.1 ng/mL vs 16.1±6.9 ng/mL;P＜0.05）。维生素D受体基因多态性FokⅠ位点病例组FF基因型明显高于对照组（53% vs 25%）,基因型分布频率差异有统计学意义（χ2=10.221,P＜0.05）,病例组F等位基因频率明显高于对照组（73% vs 57%）,等位基因分布频率差异有统计学意义（χ2=7.511,P＜0.05）。结论维生素D受体基因多态性FokⅠ位点与佝偻病有相关性,提示其在佝偻病遗传易感性方面起重要作用。［中国当代儿科杂志,2010,12（7）：544-546］     

血清维生素D水平与过敏性紫癜患儿病情及治疗的关系

目的探讨血清维生素D水平与过敏性紫癜(HSP)患儿病情及治疗的关系。方法选取2015年1~12月第1次诊断为HSP的患儿50例为HSP组,以49例健康儿童作为健康对照组。空腹采集两组儿童血清,采用ELISA法检测血清25羟基维生素D_3[25-(OH)D_3]水平。根据25-(OH)D_3检测结果将HSP患儿进一步分为维生素D正常组(20 ng/m L)(n=9)、不足组(15 ng/m L~20 ng/m L)(n=15)、缺乏组(≤15 ng/m L)(n=25)、严重缺乏组(≤5 ng/m L)(n=1)。收集HSP患儿的一般资料、临床表现、激素治疗情况、入院前病程及住院天数进行分析比较。结果 HSP组患儿血清25-(OH)D_3水平(16±6 ng/m L)低于健康对照组(29±5 ng/m L)(P0.01)。与正常组+不足组患儿[25-(OH)D_315 ng/m L]相比,缺乏组+严重缺乏组患儿[25-(OH)D_3≤15 ng/m L]肾脏受累发生率、激素使用率均增高(P0.05),中位住院天数延长(P0.05),但入院前病程差异无统计学意义(P0.05)。结论 HSP患儿血清25-(OH)D_3水平低,低血清25-(OH)D_3水平HSP患儿肾脏受累风险及激素使用率增高,住院时间延长。但补充维生素D对HSP有无治疗作用,能否缩短HSP患儿病程,改善远期预后,仍有待进一步研究。