孕期不同钙摄入量对孕产妇钙代谢的影响

目的　研究孕期不同钙摄入量对孕产妇钙代谢的影响。方法　 36名孕妇通过膳食指导和监测按钙摄入量水平随机分为传统膳食组、膳食钙干预组和膳食加钙剂联合干预组 ,对孕产期有关钙代谢指标、骨钙素及产后 45天骨密度监测。结果　血清钙磷各期各组间无差异 ( P>0 .0 5) ,随孕期进展钙吸收率、钙贮留量、血清碱性磷酸酶和尿羟脯氨酸增加 ,孕末期达高峰 ,产后下降 ;骨钙素也增加 ,产后仍增加 ;粪钙和尿钙降低 ,产后粪钙略增加而尿钙明显降低。母体腰椎骨密度组间差异显蓍 ( P<0 .0 1 )。钙摄入量与尿钙、钙贮留量和骨钙素呈正相关 ( r>0 .53,P<0 .0 1 ) ,与钙吸收率呈负相关 ( r=- 0 .51 ,P<0 .0 1 )。结论　我国传统膳食导致孕期低钙摄入情况下 ,母体虽可通过降低尿钙和粪钙的排泄 ,增加肠道钙吸收率和骨钙动员等调节 ,维持胎儿钙需要和自身血钙稳定 ,产生对摄入低钙的适应 ,但这种适应是有限的 ,不能达到较高钙贮留来满足妊娠期钙需要 ,对自身骨健康和代谢有一定影响 ,因此孕期应强调富钙食物、钙剂和 VD的补充     

不同孕期钙干预对钙及微量元素代谢的影响

目的:探讨不同孕期钙干预对钙及微量元素代谢的影响。方法:以42名年龄在21～28岁、第一胎妊娠16～18w孕妇为对象,将其分为孕中期补钙(Ⅰ)、孕中期钙联合干预(Ⅱ)、孕晚期补钙(Ⅲ)三组。Ⅰ～Ⅱ组于20±2w、Ⅲ组于32±2w开始进行钙干预(600mg/d)直至产后1w,Ⅱ组同时补充高钙奶粉40～60g/d,并于24±2w、36±2w、分娩时、产后1w分别抽取母血或脐血测定血清中Ca、P、Zn、Fe、Cu含量。另取16名未补钙剂的第一胎孕妇作对照。结果:通过膳食指导保证各组热能与营养素摄入相近。经钙干预后整个孕期与产后血清钙、磷代谢相对稳定。钙补充以孕末期为佳,产后Ⅲ组血钙高于对照组。过量钙摄入可能干扰其他微量元素、尤其是锌的代谢。结论:孕妇补钙以孕晚期为宜,避免过量钙摄入,并注意适当调整膳食结构,增加富钙食品与VD的摄入。     

中晚期妊娠钙营养干预对孕妇骨健康影响的探讨

目的:探讨妊娠期不同方式钙干预对孕期妇女骨健康的影响。方法:对59名26~36岁健康孕妇进行膳食调查,随机分为3组,即孕中期补钙组、孕晚期补钙组和对照组。在各组能量和营养素摄入相近的情况下,分别对研究组进行不同方式的钙营养支持干预。结果:孕期膳食钙摄入量每天不足450mg,孕妇血清钙、磷稳定,不随着钙摄入量的增加而改变;补充钙剂后可以增加骨钙含量。结论:孕妇膳食钙摄入量较低,但其血钙、血磷水平相对恒定,不受钙摄入量的影响,经补充钙剂有助于改善孕妇骨钙储备。     

不同钙水平对孕妇钙代谢的影响

各国孕妇钙推荐供给量是６００～１５００ｍｇ／ｄ，我国为１０００～１５００ｍｇ／ｄ，而孕妇实际钙摄入量仅为３００～８００ｍｇ／ｄ，因此我们通过研究孕期不同钙摄入水平的钙代谢、有关生化指标和骨密度，探讨我国孕妇对膳食低钙摄入的适应程度。表１各组间各期血清...     

学龄期儿童膳食钙与骨密度的关系

目的 调查上海地区学龄期儿童膳食钙摄入现状及骨营养状况,分析膳食钙与骨密度(BMD)的关系.方法 以上海市杨浦区和宝山区10所小学二、三年级学生为研究对象,每个年级随机 抽取2个班级进行定量超声BMD测量,对宝山区6所小学所有二、三年级学生采用食物频率问卷法进行钙摄入量调查,分析调查人群膳食钙与BMD关系.结果 受试儿童平均钙摄入量为647 mg/d.不同年龄别BMD间差异无统计学意义(F=1.595,P=0.173),但不同年龄别间BMD的Z值差异有统计学意义(F16.02,P=0.000).总钙摄入量与BMD及其Z值无关.乳钙占总钙的百分比与BMD及其Z值均呈显著正相关(r=0.097,P=0.015;r=0.117,P=0.003),非乳钙占总钙的百分比和非乳钙摄入量与BMD及其Z值均呈显著负相关(r=-0.097,P=0.015;r=-0.110,P=0.006).当总钙摄入量≥600mg/d时,高乳钙组的BMD及其z值明显高于低乳钙组(P<0.05).当总钙摄入量<600mg/d时,高乳钙组的BMD及其Z值较低乳钙组虽有升高趋势,但差异无统计学意义(P>0.05).结论 高乳钙摄入对BMD有促进作用,当总钙摄入量≥600 mg/d时,该作用明显增强.     

钙吸收利用与钙摄入量关系的动物实验研究

为探讨钙吸收利用与钙摄入量间的相互关系 ,给初断乳Wistar大鼠喂饲 3周缺钙饲料后 ,按体重随机分为缺钙组、钙适宜组和高钙组 ,进行 12周喂养 ,并于实验第 5周进行 3天代谢试验。结果表明 ,适宜补钙可明显增加骨钙、骨密度、骨矿物质含量和股骨的重量 (P <0 0 5 ) ,加大补钙剂量 ,补钙效果未见增加。相关分析发现摄入钙与骨钙、骨密度、骨矿物质含量呈正相关 ,而与吸收率、存留率呈负相关。量效研究发现 ,大鼠钙摄入量 (X)与吸收率 (^Y)间的关系呈双曲线函数形式 ,所得回归方程为 :^Y =e6 80 68×X- 0 882 1 +2 0 ,(F =47 315 4,P <0 0 0 0 1)。实验结果显示 ,用原子吸收分光光度计测定 ,骨钙与用单光子骨密度仪测定的骨矿物质含量具有良好的线性关系     

钙摄入量对骨密度影响的研究

[目的 ]　探讨膳食营养与骨质疏松的关系。 [方法 ]　应用膳食营养调查方法调查某厂女工的膳食营养情况 ,并在 40岁以上 3个年龄组女工中分成平时注意补钙和不注意补钙的 2组人群 ,分别对这 2组人群的钙摄入量和骨密度进行比较。 [结果 ]　各年龄组女工的钙摄入量不足 ;40岁以上各年龄组女工中 ,平时注意补充钙摄入的女工每日钙的摄入量均高于未注意补充钙组 ,骨密度也高于未补充钙组。 [结论 ]　膳食钙摄入不足 ,易致骨密度下降。骨质疏松与低钙饮食有关。     

高钙酸牛奶干预对超重和肥胖成人体重影响的研究

[目的]探讨膳食中增加乳制品对体重控制的影响.[方法]招募138名志愿接受减体重干预的超重与肥胖者,随机评价分为3组,进行3个月膳食和运动干预.[结果]酸奶组和豆浆组体重和腰围与干预前有统计学差异;自由膳食组差异无统计学意义.酸奶组人员钙摄入与BMI值有负相关(P=0.04),但豆浆组无此关系.运动干预与酸奶组和豆浆组的BMI值有极显著性影响(P值均为0.000).[结论]在增加运动的情况下,膳食中补充牛奶和豆浆对控制体重有利.     

上海市徐汇区中老年2型糖尿病患者膳食钙摄入干预研究

目的 了解上海市徐汇区糖尿病患者食物中钙摄入的情况以及和血糖控制水平的关系,探讨社区居民糖尿病血糖控制的相关因素和干预措施. 方法 采取二阶段分层随机抽样方法,选取上海市徐汇区四家街道社区卫生服务中心60～～75岁在册管理糖尿病患者中抽取单纯2型糖尿病患者共311人进行上门健康问卷调查和实验室相关指标检测,并对干预组给予营养学干预.问卷调查内容包括:基本情况及连续3d24h膳食回顾;体格检查包括测量身高、体重;实验室检查检测静脉和末梢空腹血糖.使用SPSS16.0统计学软件进行统计分析. 结果 糖尿病患者总体钙摄入中位数为524.6(375.5～～733.7)mg/d,摄入达标者仅占调查对象的13.2％.其中男性钙摄入量高于女性(P＜0.05);干预组干预后钙摄入人群分布情况、钙摄入量与基线相比,差异均有统计学意义(P＜0.01);钙摄入量和血糖控制水平未见统计学关联(P＞0.05).干预后总体样本血糖控制不良组钙摄入量高于控制良好组(P＜0.05). 结论 上海市徐汇区2型糖尿病患者膳食钙摄入量普遍不足,营养干预后糖尿病患者膳食钙结构更为合理,干预效果良好.应加强对社区糖尿病患者尤其是60岁以上女性的膳食干预.     

膳食蛋白质水平及含硫氨基酸对人体钙代谢的影响

目的：了解在我国实际膳食情况下，增加蛋白质摄入量对钙代谢的影响。方法：７名２４～３１岁的健康男性青年于４个实验期中分别轮流摄取四种不同的膳食，包括：基础膳食；基础膳食加４０ｇ鸡蛋白蛋白质；基础膳食加蛋氨酸１．９ｇ和胱氨酸１．７ｇ；以及基础膳食加牛磺酸２．４ｇ。然后观察尿钙、钙吸收及钙平衡的变化。结果：各膳食期钙的表观吸收率均无差异，补充蛋白质或补充蛋氨酸和胱氨酸使尿硫酸根及尿钙排泄量显著高于基础膳食期，并且钙平衡也均降低。补充牛磺酸对尿钙和钙平衡均无影响。结论：高蛋白质摄入对钙平衡的负面影响与含硫氨基酸蛋氨酸和胱氨酸的分解产物硫酸根排出增加有关     

Calcium nutrition and metabolism during infancy

Calcium is a vital mineral for the developing newborn infant. This review discusses perinatal and neonatal calcium metabolism, with an emphasis on enteral calcium absorption and the nutritional factors affecting calcium bioavailability including the three major endocrine hormones involved in calcium metabolism: parathyroid hormone, vitamin D, and calcitonin. The placenta transports calcium to the fetus throughout pregnancy, with the largest amount of fetal calcium accumulation occurring in the third trimester. At birth, the newborn transitions to intestinal absorption to meet the body's calcium needs. Most calcium is absorbed by paracellular passive diffusion in the small intestine. Calcium intestinal absorption is affected by the type and amount of calcium ingested. It is also affected by the amount of intestinal calcium that is bound to dietary fats and proteins. One major consequence of decreased calcium absorption is metabolic bone disease in which there is a failure of complete mineralization of the bone osteoid.     

Calcium absorption is significantly higher in adolescents during pregnancy than in the early postpartum period

BACKGROUND: Early childbearing may limit skeletal consolidation and increase calcium demands in adolescents. OBJECTIVE: The purpose of this study was to characterize calcium absorption in pregnant and lactating adolescents. DESIGN: Fractional calcium absorption was evaluated in 23 adolescents (mean +/- SD age: 16.5 +/- 1.4 y) during the third trimester of pregnancy (34.7 +/- 1.0 wk gestation) and again in 15 of these adolescents 31 +/- 8 d after delivery. Eight adolescents were breastfeeding their infants during the follow-up study. Fractional calcium absorption was determined by using oral ((46)Ca or (44)Ca) and intravenous ((42)Ca) stable calcium isotopes. Total-body and lumbar spine bone mineral density were measured in adolescents during the postpartum period by using dual-energy X-ray absorptiometry. RESULTS: Fractional calcium absorption was significantly greater during pregnancy than at 3-4 wk postpartum [0.526 +/- 0.152 (n = 23) compared with 0.297 +/- 0.108 (n = 15); P < 0.0001]. Lumbar spine z scores measured 19-44 d after delivery (n = 15) were significantly associated with calcium intake during pregnancy (y = -3.53 + 0.107x; R(2) = 0.355, P < 0.02) and were inversely related to fractional calcium absorption during pregnancy (y = 3.489 - 6.66x; R(2) = 0.52, P = 0.002). A total of 33% (5/15) of adolescents had lumbar spine z scores that met the definition of osteopenia (n = 3) or osteoporosis (n = 2) in the early postpartum period. CONCLUSIONS: Calcium absorption in adolescents was significantly higher during the third trimester of pregnancy than in the early postpartum period, and higher calcium intakes during pregnancy appeared to be protective against loss of trabecular bone at the lumbar spine.     

Calcium homeostasis during pregnancy and lactation in Brazilian women with low calcium intakes: a longitudinal study

BACKGROUND: Physiologic adjustments in calcium homeostasis during pregnancy and lactation in women with marginal calcium intakes have not been described. OBJECTIVE: The objective was to examine longitudinal changes in various aspects of calcium homeostasis during pregnancy and lactation in 9 healthy Brazilian women who habitually consumed approximately 500 mg Ca/d. DESIGN: Calcium homeostasis was assessed at 3 time points: 10-12 (early pregnancy, EP) and 34-36 (late pregnancy, LP) wk of pregnancy and 7-8 wk postpartum (early lactation, EL). At each time point, the following variables were measured: dietary calcium intake with a 3-d weighed food record, 24-h urinary calcium excretion (UCa), intestinal calcium absorption (%CaAbs) via administration of stable calcium isotopes with a breakfast meal, serum 1,25-dihydroxyvitamin D, parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), and biochemical markers of bone turnover. RESULTS: Dietary calcium did not change during the study. %CaAbs increased from 69.7 +/- 5.4% ( +/- SEM) during EP to 87.6 +/- 4.5% during LP (P < 0.05) and returned to 65.1 +/- 6.2% during EL. Compared with EP, UCa decreased 22% during LP and 68% during EL (P < 0.05). The net mean change in calcium retention was 212 mg/d during LP and 182 mg/d during EL. Several significant associations were found between the main outcome variables (%CaAbs, UCa, and markers of bone turnover) and serum hormones, especially IGF-I and PTH. CONCLUSIONS: Calcium homeostasis appears to be attained by a more efficient intestinal calcium absorption during pregnancy and by renal calcium conservation during both pregnancy and lactation. IGF-I and PTH seem to play major roles in the adjustment of calcium metabolism during pregnancy and lactation.     

围生期妇女骨量和骨代谢及其影响因素研究

目的:探讨围生期妇女骨量和骨代谢及其影响因素。方法:选取2008～2009年100例孕产妇为研究对象,将其设为观察组,选取同期的100例未孕妇女为对照组,将观察组孕早期、孕中期及孕后期和对照组的血清磷、钙、骨碱性磷酸酶、骨钙素、尿钙/肌酐及抗酒石酸酸性磷酸酶、雌二醇等进行检测及比较。结果:经研究比较发现,随着孕周的增加,观察组孕后期血清磷、钙、骨钙素降低,而则尿钙/肌酐、骨碱性磷酸酶、抗酒石酸酸性磷酸酶、雌二醇升高,孕后期与孕中期、孕前期及对照组比较,P0.05或P0.01,有统计学差异。结论:对于围生期妇女进行监测骨量和骨代谢较为重要,以便及时采取补钙措施。     

南疆263例维吾尔族孕中晚期孕妇膳食营养调查

目的 探讨分析南疆某县263例维吾尔族孕中晚期孕妇膳食营养及相关因素,为指导少数民族孕妇合理营养,促进母婴健康提供依据。方法 以新疆喀什市妇幼保健院孕妇为整群,采用整群随机抽样的方法选取263例维吾尔族孕中晚期孕妇,采用24 h回顾法进行膳食调查,结合2013年制定的《中国居民膳食营养素参考摄入量》分析比较。结果 孕中晚期维吾尔族孕妇膳食中磷、维生素B1、钠达到膳食营养素参考摄入量（dietary reference intakes,DRIs）的181.63%、120.67%和466.90%;钙、维生素B2、维生素C、铁为DDIs的42.62%、66.00%、70.12%、89.59%;叶酸、碘仅为DRIs的15.96%、14.39%。维吾尔族孕中晚期孕妇的脂肪摄入量较少。非首次妊娠的维吾尔族孕妇与蛋白质的摄入量成正相关,差异具有统计学意义（r=0.209,P=0.001）;非首次妊娠的维吾尔族孕妇与碳水化合物的摄入量成正相关,差异具有统计学意义（r=0.203,P=0.001）。结论 南疆某县维吾尔族孕中晚期孕妇摄入超标的营养素是磷、维生素B1、钠;摄入较少的营养素是维生素B2、维生素C、铁;极度缺乏的营养素是叶酸和碘。     

孕期微量元素钙铁值测定结果临床分析

目的:了解孕妇在不同孕期微量元素的变化规律,及时合理为孕妇补充微量元素提供依据。方法:将750名孕妇按周期分为早孕(<16周)、中孕(16～28周)、晚孕(>28周)三个实验组,252名未孕体检妇女为对照组,采用原子吸收分光光度法检测孕妇及对照组妇女微量元素的含量,比较实验组及对照组微量元素钙、铁的值。结果:随着孕周的增加缺乏铁的孕妇比例升高,钙元素早孕组缺乏的比例最高。结论:孕妇应定期检测,在医生的指导下早期应注意钙元素的补充,中孕期应加强铁元素的补充。     

Maternal iron status influences iron transfer to the fetus during the third trimester of pregnancy

BACKGROUND: The effect of maternal iron status on fetal iron deposition is uncertain. OBJECTIVE: We used a unique stable-isotope technique to assess iron transfer to the fetus in relation to maternal iron status. DESIGN: The study group comprised 41 Peruvian women. Of these women, 26 received daily prenatal supplements containing iron and folate (n = 11; Fe group) or iron, folate, and zinc (n = 15; Fe+Zn group) from week 10-24 of pregnancy to 1 mo postpartum. The remaining 15 women (control group) received iron supplementation only during the final month of pregnancy. During the third trimester of pregnancy (+/- SD: 32.9 +/- 1.4 wk gestation) oral 57Fe (10 mg) and intravenous 58Fe (0.6 mg) stable iron isotopes were administered to the women, and isotope enrichment and iron-status indicators were measured in cord blood at delivery. RESULTS: The net amount of 57Fe in the neonates' circulation (from maternal oral dosing) was significantly related to maternal iron absorption (P < 0.005) and inversely related to maternal iron status during the third trimester of pregnancy: serum ferritin (P < 0.0001), serum folate (P < 0.005), and serum transferrin receptors (P < 0.02). Significantly more 57Fe was transferred to the neonates in non-iron-supplemented women: 0.112 +/- 0.031 compared with 0.078 +/- 0.042 mg in the control group (n = 15) and the Fe and Fe+Zn groups (n = 24), respectively (P < 0.01). In contrast, 58Fe tracer in the neonates' circulation was not significantly related to maternal iron status. CONCLUSION: The transfer of dietary iron to the fetus is regulated in response to maternal iron status at the level of the gut.     

妊娠期补钙补铁预防妊娠高血压疾病发生的临床分析

目的:了解妊娠期同时补钙补铁对预防妊娠高血压疾病的发生的临床疗效。方法:对2009年11月至2010年11月在我院产科住院分娩的548例孕妇的资料进行回顾性分析,将孕中期开始补钙、补铁的300例孕妇作为A组,孕中期开始补钙而未补铁的118例孕妇作为B组,孕期末服用钙剂及铁剂130例孕妇作为C组,分析三组病例分娩前妊娠高血压疾病及贫血发生情况。结果:B组妊娠高血压疾病发生率明显高于A组(P<0.05),但明显低于C组(P<0.05)。B组贫血发生率明显高于A组(P<0.05),但与C组相比,两组贫血发生率无显著性差异(P>0.05)。结论:妊娠期补钙能降低高血压疾病发生率,妊娠期同时补钙补铁预防妊娠高血压疾病较单一补钙效果好。     

妊娠早期孕妇亚临床甲状腺功能减退与全血微量元素相关性研究

目的 探讨妊娠早期5种全血微量元素与亚临床甲状腺功能减退的相关性。方法 选取2016-2018年在连云港市妇幼保健院就诊的孕周为7~12周的孕妇1790例,按甲状腺功能分为亚临床甲减和正常对照2组,检测全血铜、锌、钙、镁和铁5种微量元素以及甲状腺激素的含量。采用独立样本t检验对两组间差异进行分析;血清TSH水平与各微量元素采用Pearson相关性分析。结果 妊娠早期亚临床甲减组中全血铁的含量低于正常对照组,差异具有统计学意义(P=0.035),其余微量元素在两组中的差异无统计学意义(P＞0.05);亚临床甲减组中锌和铁的含量与血清促甲状腺激素呈负相关(r=-0.257;-0.302, P=0.042;0.035 )。结论 在妊娠早期,微量元素的异常可能会影响血清促甲状腺激素的分泌,亚临床甲减孕妇需要根据检测结果合理补充锌和铁,以期预防向甲减发展,保证孕妇和胎儿的需要和正常发育。