孕妇与钙营养

孕妇钙营养及钙需要的系列研究,研究背景,孕期钙营养需要的特殊性成熟新生儿体内含钙约30g，孕末期需储钙约300mg/d；WHO/FAO制订孕期钙推荐供给量的依据包括 是以非孕妇女为基础加上胎儿发育所需钙量； 考虑钙的吸收率；1988年中国营养学会制订钙RDA为1500mg/d;,研究背景,钙的供给现状1992年全国营养调查显示，城乡人均钙摄入量为405.2mg/d，为RDA49.2%;广东城乡居民人均钙摄入量为387.5mg/d，为RDA46.5%;各地孕妇钙实际摄入量398721mg/d，为RDA 的1/31/2。,问题的提出,我国孕妇缺钙？我国孕妇对传统低钙膳食适应？传统低钙膳食对孕妇、胎儿或新生儿有什么影响？,研究的实验设计,一、动物实验以非孕雌性大鼠为对照；用含钙1.0、0.25、0.05三种饲料干预妊娠大鼠至产后，观察不同钙供给时，妊娠大鼠钙代谢的差异；钙代谢试验；45Ca小肠吸收试验；,研究的实验设计,二、人体追踪研究对象 36名孕18周妇女;分组 I（传统膳食组） 钙摄入478.5 139.7 mg/d；II(膳食钙干预组) 传统膳食+45g奶粉，钙摄入823.982.0mg/d；III(膳食加钙剂联合干预组) 传统膳食+45g奶粉+600mg钙，钙摄入量1274.6147.8 mg/d;,研究的实验设计,二、人体追踪研究内容 膳食钙干预，从孕中至产后45天；母体：钙代谢试验； 相关生化指标； 激素水平测定； 产后骨密度；子代：胎儿发育，新生儿体格；,一、妊娠机体对低钙供给的代谢改变,（一）动物试验 Table 1 Indices of calcium metabolism in pregnant rats（xs） n 1.0%Ca 0.25%Ca 0.05%CaDiet consumption(g/d) 30 14.73 1.57 16.28 2.68a 18.65 1.86a bCalcium intake(mg/d) 30 147.9218.33 39.246.76a 9.240.94a bCa of feces(mg/d) 21 115.8521.79 19.276.69a 13.101.69a bCa of urine(mg/d) 21 0.520.06 0.380.07a - AA of Ca(% ） 21 21.490.48 49.546.14a - Retention of Ca(mg/d) 21 31.5614.70 19.597.62a -4.121.88Note: a: compared with 1.0%Ca, p 0.05; b: compared with 0.25%Ca, p 0.05;,一、妊娠机体对低钙供给的代谢改变,Table 2 Indices of calcium metabolism of rats in 24hoursGroup Diet intake Ca intake AA of Ca Retention of Ca (g) (mg) （%） (mg)No-preg- 1.0%Ca 12.091.31 121.0014.85 17.457.01 20.596.540.25%Ca 13.021.21 32.773.43 35.4011.42a 11.393.18aPregnancy1.0%Ca 14.731.57 147.9218.33 21.490.48 31.5614.700.25%Ca 16.282.68a 39.246.76a 49.546.14a b 19.597.62a bNote：a: compared with1.0%Ca, p0.01; b: compared with No-pregnancy，p0.01;,一、妊娠机体对低钙供给的代谢改变,Table3 45CaCl2 uptake in duodenum, jejunum and ileum in pregnant rats (cpm/mg) 1.0%Ca 0.25%Ca 0.05%CaDuodenum 95.9218.52 136.7523.93a 169.1935.41a bJejunum 88.4318.32 124.8729.70a 155.2410.19a bIleum 92.7527.56 111.1228.25 152.5434.65ab Note: n=10 ; a: compared with 1.0%Ca, p 0.05; b: compared with 0.25%Ca, p 0.05;,Fig.1 45CaCl2 uptake in duodenum, jejunum and ileum in pregnant rats,Note: n=10 ; a: compared with 1.0%Ca, p 0.05; b: compared with 0.25%Ca, p 0.05.,a,a,ab,a,ab,ab,一、妊娠机体对低钙供给的代谢改变,妊娠、三种钙水平对肠道45Ca摄取力 23析因分析钙在十二指肠摄取力增高是妊娠和低钙供给共同作用的结果；空肠和回肠摄取力增高主要是低钙供给的结果；妊娠和低钙的共同作用增加了钙在肠道的吸收，包括肠道上段的主动吸收和下段的被动扩散；低钙供给时主要增加肠道下段的被动扩散。,一、妊娠机体对低钙供给的代谢改变,(二)人体研究Table 4 Calcium metabolism of the 3rd trimestrial pregnant women Group 1(12) Group II(12) Group III(11)Intake of Ca( mg/d) 565129 90971 137125 Ca of feces (mg/d) 14667 30732 65193 Ca of urine (mg/d) 14863 28440 32484Ca of retention(mg/d) 27174 31868 39639 AA of Ca(%) 74.686.3 66.034.3 52.57.0Note: compared with Group 1, p 0.05, p 0.01; compared with Group II, p 0.05, p 0.01; in ( ).n;,Fig.2 Calcium metabolism of the 3rd trimestrial pregnant womenNote: compared with Group 1, p 0.05, p 0.01; compared with Group II, p 0.05, p 0.01., , ,Fig.3 Calcium absorption of the 3rd trimestrial pregnant womenNote: compared with Group 1, p 0.05, p 0.01., ,一、妊娠机体对低钙供给的代谢改变,小结1. 低钙供给时, 孕及非孕大鼠饲料消耗增加，钙排出减少,肠道钙吸收率显著增加，这种改变孕鼠较非孕鼠更明显;2.妊娠状态、低钙供给，通过增加摄食量、调节肠道和肾脏的功能，使机体在有限的钙供给时储留更多的钙; 3.妊娠和低钙共同作用使钙在十二指肠摄取力增高,低钙供给主要使空肠和回肠摄取力增高;4.妊娠和低钙的共同作用增加了钙在肠道上段的主动吸收，低钙供给时主要增加肠道下段的被动扩散。,二、孕期低钙摄入对骨健康的影响,(一)动物实验 Table 5 Contents of ash and calcium in femur of the pregnant rats 1.0%Ca 0.25%Ca 0.05%CaWeight of femur(g) 0.440.04 0.400.06 0.380.04Contents of ash(mg) 0.260.02 0.240.04 0.220.02Contents of Ca(mg) 96.437.5 75.182.2 66.8450.5Note: compared with 1.0%, p 0.05; compared with 0.25%, p 0.05;,二、孕期低钙摄入对骨健康的影响,(一)动物实验Table 6 Contents of ash and calcium in femur(xs) No-pregnancy pregnancy Group 1.0%Ca(7) * 0.25%Ca(7) 1.0%Ca(7) 0.25%(7)Weight of femur(g) 0.450.02 0.420.02 0.440.04 0.400.06Contents of ash(mg) 0.260.01 0.260.01 0.260.02 0.240.04Contents of Ca(mg) 95.882.5 8.247.3 96.437.4 75.182.2 Note: compared with 1.0%Ca, p 0.05; compared with No-preg, p 0.01; in( )*： n;,二、孕期低钙摄入对骨健康的影响,(一)动物实验1.相关分析 骨钙量与大鼠钙摄入量、机体钙贮留量均显著正相关（r=0.7527和0.7021, p0.001）; 钙存留量与钙摄入量显著正相关（r=0.7519， p0.01）。2.股骨病理改变 当钙水平为0.25%时，可维持机体的正钙平衡，但出现明显的股骨钙动员的病理学体征。0.05%钙组，形态学上骨动员体征更为明显。,二、孕期低钙摄入对骨健康的影响,（二）人体研究 Table 7 Lumber bone mineral density in different groups (g/cm2)Position Group 1(12) Group II(12) Group III(11)Right spinea 0.8940.054 0.9550.054 1.0540.043Lateral middle spinea 0.6090.059 0.6680.046 0.7490.043Lateral spinea 0.6400.039 0.6850.030 0.7580.033Note: a, Average of L2L4; in ( ) n ; , compared with group 1,p0.05,p 0.01; b: compared with group II p0.05 ,p 0.01;,Right spine Lateral middle spine Lateral spine Fig.4 Lumber bone mineral density in different groups Note: , compared with group 1,p0.05,p 0.01; b: compared with group II p0.05 ,p 0.01.,二、孕期低钙摄入对骨健康的影响,（二）人体研究Table 8 BMD percentage of non-pregnancy of the same agePosition Group 1(12) Group II(12) Group III(11)Right spinea 86.675.41 92.585.48 102.454.37Lateral spinea 82.835.02 88.583.94 97.734.29Average 85.146.61 90.746.53 100.445.19Note: a, Average of L2L4; in ( ) n ; , compared with group 1,p0.01; : compared with group II, p 0.01;,Right spine Lateral spine Average Fig.5 BMD percentage of non-pregnancy of the same age Note: , compared with group 1,p0.01; : compared with group II, p 0.01.,二、孕期低钙摄入对骨健康的影响,（二）人体研究 Table3 Weight and length of the newbornGroup n length(cm) weight (g) score of the riskI 12 51.33.5 3437293 82.53.4II 12 53.32.7 3584365 86.74.4III 11 53.82.4 3431287 87.33.4Note: Compared with group I, , p0.01;,二、孕期低钙摄入对骨健康的影响,小结1.传统膳食(低钙摄入)，不影响胎儿及新生儿体格发育;2.低钙供给时，尽管母体钙代谢有一系列适应性改变，但钙存留量降低，股骨钙含量也减少;3.传统膳食(低钙摄入), 腰椎各部位骨密度显著低于膳食钙干预组及膳食加钙剂联合干预组;4.传统膳食(低钙摄入), 腰椎各部位骨密度下降至同龄非孕妇女85.14%; 膳食加钙剂联合干预(钙摄入1274.6147.8 mg/d) 可维持骨密度至同龄非孕妇女同等水平;,三、孕期钙代谢调节的相关因素,(一)骨钙素Table9 Serum BGP contents in the pregnancy phases (xs ,g/L) Group 1(12) Group II(12) Group III(11)Middle pregnancy 3.360.53 3.550.46 3.440.57Later pregnancy 3.920.52 4.760.87 4.741.46 After parturition 4.740.61 6.360.93 a 6.201.01 aNote: in ( ) n ; , compared with Middle pregnancy, p0.01; : compared with Later pregnancy, p0.05;,Middle pregnancy Later pregnancy After parturition Fig.6 Serum BGP contents in the pregnancy phases (xs ,g/L)Note: , compared with Middle pregnancy, p0.01; : compared with Later pregnancy, p0.05., a, a,三、孕期钙代谢调节的相关因素,二、雌激素Table 10 Serum estradiol contents in the pregnancy phases (xs , pg/ml) Group 1(12) Group II(12) Group III(11)Middle pregnancy 730.9267.2 720.1279.1 742.1665.9Later pregnancy 1731.5490.5 1502.6458.6 998.7226.2baAfter parturition 426.2296.3 166.7179.4a 91.625.2 ANote: in ( ) n ; compared with Middle pregnancy, p0.01; compared with Later pregnancy, p0.01; compared with grou