维生素D与毛细支气管炎的研究进展

维生素D的传统生理作用是维持人体组织细胞的正常生长发育,其缺乏会导致人体钙元素的吸收及利用率的降低,严重时可导致儿童佝偻病、骨软化症的发生。随着人们对维生素D作用的进一步研究发现,维生素D对毛细支气管炎有一定的治疗作用,并能减少日后喘息发作。     

1,25（OH）_2D_3用于抗肿瘤的研究进展

1,25-二羟维生素D3[1,25（OH）2D3]是人体必需维生素,又称为骨化三醇,是维生素D在人体内的活化形式,除了维持体内钙环境相对稳定外,还可调节多种细胞的增殖、分化,近年来对肿瘤细胞的影响备受关注。国际知名杂志Science于2002年5月报道,维生素D可以降低人们患结肠癌的风险,维生素D能帮助解除消化过程中生成的石胆酸的毒性,从而预防结肠癌的发生,但长期且大剂量的使用能导致软组织的钙化。药理作用新研究发现,     

维生素D水平与消化系统疾病相关性的研究进展

维生素D在钙、磷代谢和骨稳态中的发挥着重要的作用,同时在防治心血管疾病,保护肾脏、调节免疫、抗肿瘤等多方面的作用被关注。近年来,维生素D与消化系统疾病的相关性成为研究热点。本文旨在对维生素D水平与消化系统常见疾病的相关性进行综述。     

冬吃菌菇有讲究

草菇草菇中的维生素C含量居菌类之首;具有一定的解毒作用,如铅、砷、苯进入人体,可与其结合,随小便排出;还能减慢人体对碳水化合物的吸收,比较适合糖尿病患者食用。草菇无论是干品还是鲜品,都不宜浸泡时间过长,比较适合做汤或素炒,香菇香菇中富含钾、钙等多种矿物质,且含可以转化为维生素D的麦淄     

维生素D与糖尿病肾病的研究进展

糖尿病肾病是糖尿病常见和严重的慢性并发症之一,发病机制复杂且目前无特异性防治手段。维生素D是经典的钙磷代谢调节剂,在体内转化为1,25 二羟维生素D3(1,25(OH)2D3),与维生素D受体结合发挥生物学效应。维生素D缺乏与糖尿病及糖尿病肾病的发生、发展相关。维生素D可通过激活维生素D受体介导的核转录因子κB途径,抑制肾素 血管紧张素系统激活,降低肾素基因启动子活性,改善甲状旁腺功能亢进,抑制转化生长因子 β,抑制炎性因子、调节免疫反应及保护足细胞等机制保护肾功能、延缓肾病进展。维生素D类似物的应用已引起了大家的重视,但临床应用尚需进一步探索。     

维丁钙片中维生素D2的鉴别方法改进

维丁钙片为目前市场最为广泛使用的补钙药品。现在市场上补钙方面的药品品种极多 ,价格昂贵不等 ,而属维丁钙征的价格最为便宜 ,适用。也是广大群众能够容易接受的补钙药品而我们知道补钙关键在于摄入的钙是否能够被较好的吸收 ,而能够使钙吸收的关键是维生素D2 。维生素D促进小肠粘膜对钙磷的吸收 ,促进小管对钙磷的吸收 ,促进骨代谢 ,维持血钙 ,血磷平衡 ,维生素D缺乏时 ,儿童佝偻病 ,出现骨髓畸形 ,骨质疏松多汗等。成人骨软化 ,骨骼含有过量钙化的基质 ,出现骨骼疼痛软弱乏力等症状。1　资料与方法1.1　资料　维生素D2 鉴别项检验方法…     

新兴保健水果无花果

无花果又名天仙果、蜜果、古渡子。它含有大量的葡萄糖、果糖。其青果含糖量２０％,干果含糖量可达７０％,并且９５％是单糖,可直接被人体吸收。其维生素Ｃ的含量是柑橘的２．３倍、桃子的８倍、梨的２．７倍。无花果中,人体必需的１７种氨基酸的含量也很丰富,尤其是抗疲劳的天门冬氨酸含量最高。无花果内还含有一种超氧化物歧化酶,可激活体内免疫系统细胞,起到延缓衰老、延年益寿的作用。此外,无花果内还含有蛋白质、维生素Ａ、维生素Ｄ及钙、磷、铁、铜、锌、硼等矿物质。因此,它成为当今世界上新兴的保健水果。近年来,营养学家…     

如何增强机体的免疫力?

免疫系统相当于一个国家的卫士和警察,它能摧毁敌人———各种致病生物,保卫人体的健康和生命安全。当免疫系统失灵后,病毒、细菌等致病生物便会畅通无阻地侵入人体,导致灾难性的疾病。一个人要想获得和维持良好的免疫能力,需要适当补充有关的维生素、矿物质以及有充足的睡眠。适当补充有关的营养素维生素A维生素A有助保持消化道、肺部以及细胞膜的完整,防止病毒进入细胞。维生素A还能让鼻粘膜、支气管粘膜变得强壮,足以抵御有害气体和灰尘的不良刺激,避免人体受到病毒、细菌的侵犯。有专家称:维生素A对提高人体的免疫力功劳最大!维生素C…     

妊娠晚期应补维生素D

维生素D的主要功用是促进人体肠道对钙、磷的吸收,保证血钙、磷浓度的相对稳定,从而有利于骨骼的生长、发育和钙盐在骨骼中的沉积,预防佝偻病、软骨病和骨质疏松症的发生。妇女在妊娠期对营养物质的需求具有双重性,即既要满足自身新陈代谢的需要,又要满足胎儿生长发育的需要。到了妊娠晚期,胎儿的生长发育速度,尤其是骨骼发育速度加快,这就需要从母体得到更多的钙、磷补充,这也必然增加了母体对维生素D的需求量。另外,妇女怀孕至32周后,均有不同程度的血清维生素D3水平下降。如果不及时给母体补充维生素D3,其不良影响就会波及胎儿,有可能…     

膳食维生素D和磷水平对悬吊大鼠骨 肌肉与肾的影响

本实验观察了正常和高磷摄入时,补充高量维生素D_3对尾吊(30天)大鼠股骨、腓肠肌和肾成分及其它指标的影响。结果表明,在膳食钙磷含量和比值正常时(Ca:P=0.6%:0.6%),与适量维生素D摄入(膳食维生素D含量为2000IU/kg)比较,高维生素D摄入(10000IU/kg)不但不能减轻悬吊大鼠股骨的骨丢失,反而导致肾脏出现轻度病理变化,腓肠肌萎缩加重,高钙血和血清碱性磷酸酶活性(ALP)增强。在膳食磷含量增加时(1.8%),高维生素D摄入能显著减轻悬吊大鼠股骨的骨丢失,但也加重高磷摄入对肾脏的损伤,并有体重减轻和腓肠肌萎缩加重等副作用。结果提示,在失重和模拟失重条件下,机体对维生素D毒性作用的耐受能力可能减低,补充高剂量维生素D是有害的。     

Vitamin D metabolism,rickets, and osteomalacia

Rickets in the growing child or adolescent and osteomalacia in the adult develop in a variety of clinical situations and have in common an absence or delay in the mineralization of growth cartilage and in newly formed bone collagen. Classically, deficiency of vitamin D, which is essential for the absorption of dietary calcium, has been the major cause. However, rickets is also seen as a result of hereditary defects in critical vitamin D signaling molecules. Disturbances of phosphate metabolism can also lead to signs of rickets and osteomalacia, notably X-linked hypophosphatemic rickets, and oncogenic osteomalacia. Extrarenal synthesis of 1,25-dihydroxyvitamin D, such as that associated with granulomatous disease, can also lead to disturbances in calcium metabolism, with associated skeletal and nonskeletal changes.     

儿童血清25-羟维生素D水平与超声骨密度关系研究

目的 调查分析儿童血清维生素D营养状况及与超声骨密度关系,为科学合理补充维生素D及钙剂提供依据.方法 选取儿保科门诊常规体检的1~10岁儿童368名为研究对象,采用化学发光法测定血清25-羟维生素D水平,定量超声骨密度仪测取骨密度值.结果 所选儿童血清25-羟维生素D平均水平为(28.36±12)ng/ml,超声骨密度平均水平为(-0.07±0.10).随着年龄增加,维生素D水平逐渐下降,25-羟维生素D缺乏组、不足组中超声骨密度不足率均较充足的组别高(P<0.05),男女童25-羟维生素D及超声骨密度均值比较无统计学意义(P>0.05).6~岁年龄组25-羟维生素D与骨密度呈正相关(P<0.05).结论 泸州市儿童25-羟维生素D及超声骨密度普遍不足,两者仅在一定年龄可能有关,临床上应结合两种检查,科学合理补充维生素D及钙剂.     

Effects of vitamin D supplementation on salivary immune responses during Marine Corps basic training

Vitamin D's role in regulating immune responses may increase during periods of elevated psychological and physiological stress. Due to the high demands placed on US Marine Corps recruits undergoing 12 weeks of basic military training, we hypothesized that vitamin D status would be related to markers of innate mucosal immunity, and daily vitamin D supplementation would augment immune responses during training. Males (n = 75) and females (n = 74) entering recruit basic training during the summer and winter volunteered to participate in a randomized, double‐blind, placebo‐controlled study. Subjects received either 1000 IU vitamin D₃ + 2000 mg calcium/d (n = 73) or placebo (n = 76) for 12 weeks. Saliva samples were collected pre‐training, during (weeks 4 and 8), and post‐training (week 12) in order to determine salivary SIgA and cathelicidin (indices of mucosal immunity) and α‐amylase (indicator of stress). Initial (baseline) and post‐training serum 25(OH)D levels were measured. Results were as follows: serum 25(OH)D levels were 37% higher in recruits entering training in summer compared with winter. A positive relationship was observed between baseline 25(OH)D levels and SIgA secretion rates (‐SR). When stress levels were high during summer training, baseline 25(OH)D levels contributed to an increase in salivary secretory immunoglobulin A secretion rates (SIgA‐SR) and cathelicidin‐SR, the latter only in males. Vitamin D supplementation contributed to the changes in SIgA‐SR and cathelicidin‐SR, specifically SIgA‐SR was higher in the treatment group. These data highlight the importance of vitamin D and mucosal immune responses during arduous basic military training when stress levels are increased.     

高原边防部队膳食营养调查分析

目的 了解高原边防部队膳食营养现状,为高原部队食物及营养素推荐摄入量标准的制定提供依据.方法 采用GJB 1636A-2016中称重法和体格检查法对驻海拔4600 m(A部)和4030 m(B部)单位的膳食营养情况进行调查.按GJB826B-2010和GJB823B-2016进行膳食质量评价;高效液相色谱法检测血浆维生素A含量,ELISA法检测血浆25-OH VD含量;上臂肌围采用GJB1636A-2016评价,体脂率采用体成分仪所附标准评价.结果 A部禽蛋、牛奶和植物油摄入达标,其余食物未达标;B部粮食和植物油摄入达标,其余食物摄入未达标.A部蛋白质、钙、磷、钠、铁、硒、碘、铜、锰、维生素E、B3摄入充足,能量、钾、锌、镁、维生素D、C、B1和B2摄入不足,维生素A、B6、B9和B12严重缺乏;B部能量、蛋白质、磷、钾、钠、锌、铁、硒、镁、铜、锰、维生素E、C、B1和B3摄入充足,维生素B2摄入不足,钙、碘、维生素A、D、B6、B9和B12严重缺乏.A部蛋白质和脂肪产热达标,碳水化合物产热过低;B部蛋白质产热达标,脂肪产热超标,碳水化合物产热过低.两单位人员血浆维生素A含量充足;血浆25-OH 维生素D含量不足及缺乏.A部和B部上臂肌围正常人数比分别为93.5%和97.7%,体脂率偏瘦人数比分别为80.6%和70.5%.结论 高原边防部队的食物和营养素摄入不均衡,机体维生素D缺乏,但蛋白质营养状况较好,体脂较低,还需调整膳食结构和进行营养宣教来改善高原部队膳食营养现状.     

Vitamin D: Biochemistry and clinical applications

Major advances in the field of vitamin D metabolism have been achieved in the past decade that have considerably enhanced our understanding of a variety of metabolic bone diseases which include the rachitic and osteomalacic syndromes and parathyroid gland disorders. Delineation of the biochemical structure, metabolic pathways, mechanisms regulating synthesis, and physiologic functions has established that the compound should more appropriately be considered a hormone. Obligatory sequential, two-step hydroxylation of the prohormone, vitamin D, is necessary before physiologic action occurs. Initial hydroxylation occurs mainly in the liver while the second hydroxylation occurs exclusively in the kidney. The physiologically active form of the hormone, 1,25-(OH)₂-D, coordinates with parathyroid hormone (and probably calcitonin) in promoting homeostasis of both extra-cellular calcium and phosphorus and the skeletal system. This article reviews the basic metabolism of vitamin D, the modes of physiologic action, the endocrine features of vitamin D and its relationship to parathyroid hormone, and discusses the important medical applications of this information.     

Vitamin D and Human Skeletal Muscle

Vitamin D deficiency is an increasingly described phenomenon worldwide, with well‐known impacts on calcium metabolism and bone health. Vitamin D has also been associated with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. In recent decades, there has been increased awareness of the impact of vitamin D on muscle morphology and function, but this is not well recognized in the Sports Medicine literature. In the early 20th century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and increasingly, evidence is accumulating to support this view. Both cross‐sectional and longitudinal studies allude to a functional role for vitamin D in muscle and more recently the discovery of the vitamin D receptor in muscle tissue provides a mechanistic understanding of the function of vitamin D within muscle. The identification of broad genomic and non‐genomic roles for vitamin D within skeletal muscle has highlighted the potential impact vitamin D deficiency may have on both underperformance and the risk of injury in athletes. This review describes the current understanding of the role vitamin D plays within skeletal muscle tissue.     

Vitamin D status of females in an elite gymnastics program.

OBJECTIVE: Vitamin D plays an important role in calcium and bone metabolism. In Australia it has been assumed that all young athletes have good vitamin D levels. A survey of females in an elite gymnastics program was undertaken to determine their vitamin D and dietary calcium status. DESIGN: Cross-sectional survey. SETTING: Females in an elite gymnastics program at the Australian Institute of Sport. PARTICIPANTS AND OUTCOME MEASURES: Eighteen female gymnasts aged 10-17 years were assessed for vitamin D status (serum 25[OH]D) and dietary calcium intake. RESULTS: Fifteen were found to have levels below current recommended guidelines for optimal bone health (<75 nmol/L). Six had vitamin D levels below 50 nmol/L. Thirteen of the gymnasts also had daily dietary calcium intakes below the daily recommended intake for their age. CONCLUSIONS: Gymnasts and possibly other indoor athletes should be carefully reviewed for vitamin D and calcium status.     

Oxidative stress : relationship with exercise and training

Free radicals are reactive compounds that are naturally produced in the human body. They can exert positive effects (e.g. on the immune system) or negative effects (e.g. lipids, proteins or DNA oxidation). To limit these harmful effects, an organism requires complex protection - the antioxidant system. This system consists of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase) and non-enzymatic antioxidants (e.g. vitamin E [tocopherol], vitamin A [retinol], vitamin C [ascorbic acid], glutathione and uric acid). An imbalance between free radical production and antioxidant defence leads to an oxidative stress state, which may be involved in aging processes and even in some pathology (e.g. cancer and Parkinson's disease). Physical exercise also increases oxidative stress and causes disruptions of the homeostasis. Training can have positive or negative effects on oxidative stress depending on training load, training specificity and the basal level of training. Moreover, oxidative stress seems to be involved in muscular fatigue and may lead to overtraining.     

Dynamic changes in calcium and phosphate plasma concentrations in the patients on peritoneal dialysis

BACKGROUND/AIM: The disturbances of active forms of vitamin D synthesis and disturbances in calcium and posphate metabolism develop early in chronic renal failure, when creatinine clearance is about 30 ml/min. Chronic hemodialysis and peritoneal dialysis only partially correct the biochemical enviroment of patients on chronic renal replacement therapy because of end-stage renal disease. These dialysis modalities can't signifficantly affect the endocrine disturbances of chronic renal failure and they have minimal modulatory effect. The management of disturbed calcium (Ca) and phosphate (P) metabolism and the maintainance of Ca x P product below 4.4 mmol/l thanks to the use of dialysate solutions with the appropriate calcium concentration and the careful dosage of phosphate binders, calcium and active vitamin D metabolits, are extremely important for the prevention of renal osteodystrophy, secondary hyperparathyroidism as well as low-bone turnover disease. The aim of the study was to analyze the plasma levels of calcium, phosphate, albumin, alkaline phosphatase and parathormon (PTH) in 58 patients who were treated with continuous ambulatory peritoneal dialysis (CAPD) from March to August 2003. The use of phosphate binders and the substitution with active vitamin D metabolits were also analyzed. METHODS: We examined 58 patients, 30 males and 28 female, mean-age 52 years (range, 26-78 years), affected by end-stage renal disease of the different leading cause. The average time on peritoneal dialysis program was 20 months (2-66 months). Most of the patients were treated by CAPD, while only few of them performed authomatic, cyclic or intermitent peritoneal dialysis. Most of the patients used a dialysate with 1.75 mmol/l calcium concentration. RESULTS: The study showed that our patients on chronic CAPD program during several months had normal calcemia, phosphatemia and the level of alkaline phosphatase, and that they had Ca x P product in the recommended range. PTH serum level ranged from 16 to 490 pg/l in our patients. CONCLUSION: The study showed that a balanced diet and a correct dosage of phosphate binders, as well as a careful substitution with active vitamin D metabolits render a good control of calcium and phosphate serum balance, as well as an effective prevention of renal osteodystrophy development in the patients on chronic peritoneal dialysis treatment.     

Mineral metabolism of the growing bone and its disturbances--methods of radiological examinations (author's transl)]

New possible interactions of vitamin D and its derivates are discussed with reference to metabolism of calcium and phosphorous and its effects on the skeletal system. The degree of osteoporosis and osteomalacia determined only by means of roentgenology depends on subjective factors. A survey is presented about objective determination which includes skeletal mineral content by radiology and nuclear medicine examination. Following a survey of our own investigative methods and results the follow-ups in various forms of vitamin D refractory rickets are reported.