营养Q&A

正6个月宝宝应该喂维生素D_3还是鱼肝油(维生素AD)昵?A首先,需要知道宝宝是纯母乳喂养还是配方粉喂养。对于纯母乳喂养的宝宝,如果妈妈的饮食非常均衡,是无须给宝宝补充维生素A的,只需要补充维生素D即可。补充维生素D的原因在于:婴儿出生时体内维生素D贮存水平较低,在头几个月依靠母乳、日照或者辅食摄入维生素D。而母乳中的维生素D通常含量较低,生长在高纬度地区的婴儿,日光条件有限或者受文化或其他因素的影     

补充维生素A和铁对孕妇铁营养状况的影响

目的　研究补充维生素 A、铁对孕妇铁营养状况的影响。方法　对 1 6 7名孕中期妇女进行铁和维生素 A营养状况的横断面调查并随机分成 4组 :对照组 (复合维生素 B片每日一片 ) ;补充维生素 A组 (1 1 0 0 μg/d) ;补充铁组 (6 0 mg/d元素铁 ) ;补充维生素 A和铁组 (VA1 1 0 0μg/d,Fe6 0 mg/d) ,共补充 1 0 w。结果　被调查孕妇孕中期维生素 A轻度缺乏率为 0 .6 % ,贫血患病率为 7.8% ,贮存铁缺乏率为 6 .2 %。血清 VA水平补充前各组正常 ,补充后对照组明显下降 ,但仍维持在正常范围。补 VA、补铁及补 VA+铁组血清 VA与补充前无明显差异 ,仍保持恒定。各组补充前后 Hb均在正常范围 ,差别不显著。血清铁蛋白、游离红细胞原卟啉及运铁蛋白饱和度补充后的改善效果均以补充 VA铁组优于单独补 VA或补铁组。结论　孕期同时补充 VA和铁对改善铁的营养状况优于单纯补铁。     

手术创伤病人维生素A、E的补充

观察了食道癌、胃癌、肺癌、脓胸等18例病人术后补充维生素的结果.按维生素A(VA)15000IU/d;维生素E(VE)100mg/d剂量补充1～3周,测定血清中VA、VE及脂质过氧化物(LPO)的含量.结果提示;胸腹部手术创伤病人,补充上述剂量维生素后,可使血清VA、VE浓度维持在良好的营养水平.但尚不能使血清LPO下降至正常水平.同时对病人手术前的膳食提出了建议.     

6月龄婴儿维生素A缺乏症的影响因素研究

目的调查深圳市龙岗区6月龄婴儿维生素A水平,分析维生素A缺乏症的影响因素,为维生素A缺乏症的防控提供依据。方法以2019年1—12月在龙岗区妇幼保健院儿保门诊接受健康体检的1638例6月龄婴儿为研究对象,检测婴儿血清维生素A水平,并分析维生素A缺乏症可能的影响因素。1638例婴儿根据喂养方式分为母乳喂养组(n=1005)、混合喂养组(n=228)和配方奶喂养组(n=405);根据维生素AD补充情况分为持续补充组(n=183)、交替补充组(n=420)及单独补充组(n=1035)。结果6月龄婴儿血清维生素A平均水平为(0.30±0.07)mg/L。维生素A缺乏的婴儿882例(53.84%),维生素A平均水平为(0.24±0.03)mg/L,其中边缘型维生素A缺乏795例(48.53%),亚临床型维生素A缺乏87例(5.31%);维生素A正常的婴儿756例,维生素A平均水平为(0.36±0.06)mg/L。持续补充组维生素A缺乏症检出率明显低于交替补充组及单独补充组,差异均有统计学意义(χ²值分别为26.818、36.050,均P<0.05)。母乳喂养组及混合喂养组维生素A缺乏症检出率均高于配方奶喂养组,差异均有统计学意义(χ²值分别为113.482、47.534,均P<0.05)。早产的婴儿维生素A缺乏症检出率高于足月的(χ²=16.957,P<0.05)。多因素二分类Logistic回归分析显示母乳喂养(OR=4.196)、混合喂养(OR=3.466)增加了婴儿维生素A缺乏症的发生风险(均P<0.05);持续补充维生素AD(OR=0.361)、足月(OR=0.326)、6月龄时未患营养不良(OR=0.257)、6月龄内未患呼吸道感染(OR=0.675)降低了维生素A缺乏症的发生风险(均P<0.05)。结论深圳市龙岗区6月龄婴儿维生素A缺乏症检出率较高,母乳喂养儿、混合喂养儿及早产儿出生后6月龄内应及时、合理地补充推荐摄入量的维生素AD。     

广西地区孕妇常规保健下血清维生素A、E水平分析

<正>维生素A、E(VA、VE)是人体必须的营养素,对正常妊娠的维持及保障母婴健康有重要作用,其缺乏和过量均增加妊娠期并发症和出生缺陷的风险。本研究对广西地区常规保健下的孕妇孕早、中、晚期血清VA、VE水平进行调查,评价该地区孕妇血清VA、VE的摄入状态,指导孕期维生素的合理补充。     

维生素A干预对大鼠抗氧化能力及细胞膜流动性影响的研究

目的　通过对大鼠补充不同剂量维生素A(VA)观察机体抗氧化能力及对红细胞膜流动性的影响 ,了解抗氧化活性的最佳剂量。方法　将Wistar大鼠随机分为 4组 ,分别为维生素A缺乏组 (VA1组 )补充1 1 4 3(VA2组 )、4 2 86 (VA3组 )和 1 4 2 86 μgRE·kg- 1 ·d- 1 (VA4组 )维生素A三个剂量组。测定各组大鼠血浆VA含量、SOD、MDA和GSH Px的含量和活性 ,用荧光偏振度P值和微粘度 η值评价红细胞膜的流动性。 结果　各组血浆中VA水平随补充剂量的增加而增加。血浆中SOD、GSH -Px和MDA的结果显示 ,补充剂量为VA2、VA3组SOD的水平较VA缺乏组和VA4组明显偏低 (P <0 0 1 )。VA3组的MDA较其它 3个剂量组明显下降 (P <0 0 1 )。VA4组的SOD、MDA含量明显高于其它三个剂量组 (P <0 0 1 )。VA3组血浆中GSH -Px的活性明显升高 ,P <0 0 1。细胞膜流动性的结果显示 :VA3组P值最小 (P <0 0 1 ) ;VA4组P值明显增高 (P<0 0 1 )。微粘度 η在VA3组与VA缺乏组和VA2组之间未见明显差异 ,与VA4组相比明显下降 (P <0 0 1 )。结论　维生素A补充剂量为 4 2 86 μgRE·kg- 1 ·d- 1 时 ,能够发挥较好抗氧化作用 ,红细胞膜的流动性明显增加 ,过量摄入维生素A可造成机体的中毒反应 ,增加机体的氧化损伤     

中国城乡不同泌乳阶段母乳维生素A和维生素E含量研究

目的 描述我国不同泌乳阶段和城乡母乳维生素A(VA)和维生素E(VE)的含量.方法 在全国11个省、市、自治区20个县(区)招募产后6481对健康母婴并采集母乳样本.按调查点和泌乳期分层随机抽取约15％ 样本共获得924份母乳,采用HPLC法分析VA(视黄醇)和VE(α-生育酚)含量.结果 初乳(n=179)、过渡乳(...     

维生素A及维生素C对肺巨噬细胞产生活性氧及细胞因子的影响

目的 为观察维生素 A(VA)及维生素 C(VC)对肺巨噬细胞(肺 Mφ)功能的影响.方法 以大鼠为动物模型观察VA及VC对大鼠肺Mφ产生自由基(Q_2~-,H_2O_2)及细胞因子(IL-1,TNF-α)的影响.结果 补充 VA及 VC均明显增加肺Mφ的吞噬功能及O_2~-、H_2O_2 产生(P<0.01);补充 VA可明显增加细胞因子(IL-1,TNF-α)的产生(P<0.05),而补充VC效果不明显.结论 适当补充VA可活化肺Mφ,对防治呼吸道感染有重要意义.     

补充维生素A对接种麻疹疫苗的学龄儿童IgG抗体水平的影响

目的:探讨补充维生素A(VA)对强化接种麻疹疫苗的学龄儿童产生的麻疹IgG抗体的影响。方法:选珠三角地区某市山区105名小学生,其中53名为补充组,另52名年龄、性别相匹配的儿童作为对照组,两组均接种麻疹疫苗,补充组儿童在接种疫苗的当天开始服用VA(2500IU/d),连续口服1个月,应用高效液相色谱(HPLC)法测定补充前后和对照组血清中VA含量。用酶联免疫吸附试验(ELISA)间接法测定接种前后麻疹特异性IgG抗体。结果:补充组血清中VA显著升高,为376.5±74.2μg/L,两组接种麻疹疫苗一个月后,VA补充组抗体阳性率由69.8%上升至100.0%,保护率由5.6%上升至60.4%;对照组阳性率由71.2%上升至100.0%,保护率由0%上升为17.4%。麻疹免疫之后,两组的抗体阳性率都大大升高,但VA补充组的保护率比对照组升高明显。结论:补充维生素A对接种麻疹疫苗的学龄儿童(特别是缺乏VA的儿童)所产生的抗体水平升高起到明显的促进作用。     

北京市婴幼儿血清维生素A及母乳与鲜牛乳维生素A含量的调查

测定北京城区与近郊区163例1(1/2)岁以下牛乳喂养儿血清维生素A(VA),发现城区小儿高于郊区,未添加VA 制剂小儿56.85%血清VA 含量不足(<30μg/dl),4例添加VA 制剂过多致血清VA 过高(>10μg/dl)。测定623例正常足月新生儿血清VA,83.63%低于30μg/dl,60.19%低于20μg/dl。测21例42天母乳喂养儿与母血清VA 及母乳VA 含量,母血清VA 高于小儿,母乳居中。初乳VA 浓度高于成熟乳,母乳VA 含量哺乳后高于哺乳前。鲜牛奶中VA 含量冬春季略低于夏季,皆较低。为了解决牛乳喂养儿VA 不足与少数小儿VA 过量问题,北京1987年开始制造了维生素AD 强化牛奶,初步观察预防VA 缺乏与过量皆有满意的效果。     

母乳中维生素D水平及影响因素研究

近年来的研究表明维生素D(VitD)不但发挥调节钙磷代谢,维持骨骼健康的作用,而且对骨骼外系统发挥重要作用。所以VitD的摄入和最佳营养状况问题越来越受关注。尽管VitD的营养主要靠阳光照射途径,但对婴儿来说母乳也是其重要途径之一。而母乳中VitD的水平究竟是多少?有哪些因素影响到母乳中VitD的水平?母乳喂养的婴儿摄入多大剂量的VitD制剂最合适? 本文对这些方面的研究进展进行总结,以便更好地指导母乳喂养婴儿的VitD摄入问题。     

维生素A强化牛乳预防婴儿维生素A不足的效果观察

本文观察了出生至15个月食用维生素A强化牛乳(维生素A2000IU/L)629例,和食用普通牛乳或母乳834例小儿一年四季血清中维生素A浓度。结果表明,日食维生素A强化牛乳500ml或以上,不另加维生素A制剂,可预防维生素A不足与过量,并可治疗维生素A的缺乏。     

Comparison of Vitamin D and 25-Hydroxyvitamin D Concentrations in Human Breast Milk between 1989 and 2016–2017

Background: Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016–2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016–2017) and vitamin D status in human breast milk was also evaluated. Method: Lactating mothers were recruited from three regions of Japan in 1989 (n = 72) and 2016–2017 (n = 90), and milk from 3–4 months was collected in summer and winter. The samples were strictly sealed and stored at −80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016–2017 were assessed. Results: Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016–2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D₃ concentrations. Conclusion: The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.     

Chemical contaminants in breast milk and their impacts on children's health: an overview

Human milk is the best source of nutrition for infants. Breast milk contains the optimal balance of fats, carbohydrates, and proteins for developing babies, and it provides a range of benefits for growth, immunity, and development. Unfortunately, breast milk is not pristine. Contamination of human milk is widespread and is the consequence of decades of inadequately controlled pollution of the environment by toxic chemicals. The finding of toxic chemicals in breast milk raises important issues for pediatric practice, for the practice of public health, and for the environmental health research community. It also illuminates gaps in current knowledge including a) insufficient information on the nature and levels of contaminants in breast milk; b) lack of consistent protocols for collecting and analyzing breast milk samples; c) lack of toxicokinetic data; and d) lack of data on health outcomes that may be produced in infants by exposure to chemicals in breast milk. These gaps in information impede risk assessment and make difficult the formulation of evidence-based health guidance. To address these issues, there is a need for a carefully planned and conducted national breast milk monitoring effort in the United States. Additionally, to assess health outcomes of toxic exposures via breast milk, it will be necessary to examine children prospectively over many years in longitudinal epidemiologic studies that use standardized examination protocols that specifically assess breast milk exposures. Finally, current risk assessment methods need to be expanded to include consideration of the potential risks posed to infants and children by exposures to chemical residues in breast milk.     

High breast milk levels of polychlorinated biphenyls (PCBs) among four women living adjacent to a PCB-contaminated waste site.

As a consequence of contamination by effluents from local electronics manufacturing facilities, the New Bedford Harbor and estuary in southeastern Massachusetts is among the sites in the United States that are considered the most highly contaminated by polychlorinated biphenyls (PCBs). Since 1993, measures of intrauterine PCB exposure have been obtained for a sample of New Bedford area infants. Among 122 mother-infant pairs, we identified four milk samples with total PCB levels that were significantly higher than the rest, with estimated total PCBs ranging from 1,100 to 2,400 ng/g milk fat compared with an overall mean of 320 ng/g milk fat for the 122 women. The congener profile and history of one case was consistent with past occupational PCB exposures. Otherwise, the source of PCB exposures in these cases was difficult to specify. Environmental exposures including those from fish consumption were likely, whereas residence adjacent to a PCB-contaminated site was considered an unlikely exposure source. In all four cases, the infants were full-term, healthy newborns. Because the developing nervous system is believed to be particularly susceptible to PCBs (for example, prenatal PCB exposures have been associated with prematurity, decrements in birth weight and gestation time, and behavioral and developmental deficits in later infancy and childhood, including decrements in IQ), it is critical to ascertain if breast-feeding is a health risk for the women's infants. Despite the potential for large postnatal PCB exposures via breast milk, there is limited evidence of significant developmental toxicity associated with the transmission of moderate PCB concentrations through breast milk. Breast-feeding is associated with substantial health benefits including better cognitive skills among breast-fed compared with formula-fed infants. We conclude, based on evidence from other studies, that the benefits of breast-feeding probably outweigh any risk from PCB exposures via breast milk among the four New Bedford infants. In this case report, PCB analysis of breast milk and infant cord serum was a research tool. PCB analysis of milk is rarely done clinically, in part because it is difficult to use the results of such analyses to predict health risks. Substantial effort is needed to achieve a better understanding of the clinical and public health significance of PCB exposures, particularly among potentially susceptible groups such as infants and children. Such efforts are critical to improving the clinical and public health management of widespread and ongoing population exposures to PCBs.     

维生素A缺乏与新生儿感染性肺炎发病相关性研究

目的 分析维生素A缺乏(VA)与新生儿感染性肺炎发病的关系,为临床诊治提供参考依据。方法 选取2018年1-6月门诊患儿206例,检测其血清VA水平,比较不同VA水平患儿的感染性肺炎发病率,按照是否罹患感染性肺炎以及肺炎的严重程度不同,比较分组间VA水平的差异;对于肺炎患儿随机分为实验组及对照组,对照组采用常规治疗,实验组在常规治疗基础上给予口服VA 1 500 U/d,对临床治疗效果进行比较。结果 1)206例新生儿中,116例存在VA缺乏,51例存在边缘型VA缺乏,39例正常水平。VA水平越低,感染性肺炎发病率越高,差异有统计学意义(χ²=10.02,P=0.007)。2)肺炎组患儿VA水平[(0.182±0.079) mg/L]显著低于非肺炎组[(0.236±0.098) mg/L],差异有统计学意义(t=4.570,P<0.001)。重度肺炎患儿血清VA[(0.125±0.041)mg/L]显著低于轻度肺炎患儿VA水平[(0.212±0.078)mg/L],差异有统计学意义(t=4.62,P<0.001)。3)VA辅助治疗后实验组患儿气促、咳嗽、呛奶、肺部啰音等临床症状持续时间显著低于对照组,差异有统计学意义(P<0.05)。结论 新生儿血清VA水平与新生儿感染性肺炎发病存在紧密联系,低剂量维生素A佐治新生儿感染性肺炎疗效显著,可明显缩短临床症状持续时间。     

Impact of Maternal Daily Oral Low-Dose Vitamin A Supplementation on the Mother-Infant Pair: A Randomised Placebo-Controlled Trial in China

Background: The nutritional status of vitamin A in lactating mothers and infants is still not optimistic. Due to the dietary habits and dietary restrictions of postpartum customs in China, vitamin A supplementation has been advocated as a potential strategy to improve vitamin A status of lactating mothers with inadequate dietary vitamin A intake. Existing clinical trials are limited to single or double high-dose maternal administrations. However, in China, vitamin A supplements are readily available in the form of daily oral low-dose supplements, and the effect of these is unknown. This study aimed to evaluate the effects of daily oral low-dose vitamin A supplementation on the retinol levels in the serum and breast milk of lactating mothers and the health status of infants in China. Methods: Lactating mothers who met the inclusion criteria and planned to continue exclusive breastfeeding were randomly assigned to receive either daily oral vitamin A and D drops (one soft capsule of 1800 IU vitamin A and 600 IU vitamin D₂), or a matching placebo for 2 months. Before and after the intervention, dietary intake was investigated by instant photography, and the retinol concentration in maternal serum and breast milk was determined by ultra-high performance liquid chromatography-tandem mass spectrometry. During the trial, the health status of infants was diagnosed by a paediatrician or reported by lactating mothers. A total of 245 participants completed the study, with 117 in the supplementation group and 128 in the control group. Results: After the 2-month intervention, maternal serum retinol concentrations increased in the supplementation group with no change in the control group. Although breast milk retinol concentrations decreased significantly in both groups, the decrease in the supplementation group was significantly lower than that in the control group. However, maternal vitamin A supplementation was not associated with a lower risk of infant febrile illness, respiratory tract infection, diarrhoea, and eczema. Conclusions: Daily oral low-dose vitamin A supplementation is helpful in improving maternal vitamin A status, despite having no effect on infant health status through breast milk.     

Vitamin A supplementation of women postpartum and of their infants at immunization alters breast milk retinol and infant vitamin A status

Vitamin A supplementation of lactating mothers and of infants at the time of diphtheria-pertussis-tetanus (DPT) and oral polio vaccine (OPV) immunizations have both been suggested as measures to prevent deficiency among infants. This multicenter randomized, double-blind, placebo-controlled trial was conducted in Ghana, India and Peru to determine the effect of maternal vitamin A supplementation on breast milk retinol and of maternal and infant supplementation on infant vitamin A status. Mothers in the intervention group received 60 mg vitamin A (as retinol palmitate) at 18-42 d postpartum; their infants were given 7.5 mg three times, i.e., at 6, 10 and 14 wk of age with DPT and OPV immunizations. Mothers and infants in the comparison group received a placebo. Maternal supplementation resulted in higher breast milk retinol at 2 mo postpartum [difference in means 7.1, 95% confidence interval (CI), 3.4, 10.8 nmol/g fat] and lower proportion of mothers with breast milk retinol < or = 28 nmol/g fat (15.2 vs. 26.6%, 95% CI of difference -16.6, -4.1%). At 6 and 9 mo, maternal supplementation did not affect breast milk retinol or the proportion of mothers with low breast milk retinol. Vitamin A supplementation of the mothers and their infants reduced the proportion of infants with serum retinol < or = 0.7 micro mol/L (30.4 vs. 37%, 95% CI of difference -13.7, 0.6%) and that with low vitamin A stores as indicated by the modified relative dose response (MRDR) > 0.06 (44.2 vs. 52.9%, 95% CI of difference -16.6, -0.9%) at 6 mo. Supplementation had no effect at 9 mo. The beneficial effect of supplementation on breast milk retinol and infants' vitamin A status varied by site. It was greatest in India followed by Ghana and Peru. At the doses used, maternal supplementation improved breast milk retinol status at 2 mo (P < 0.001) and maternal and infant supplementation modestly increased (P = 0.03) infant vitamin A status at 6 mo of age. Additional strategies to improve vitamin A status of 6- to 9-mo-old infants must be considered.     

Breast milk vitamin B-12 concentrations in Guatemalan women are correlated with maternal but not infant vitamin B-12 status at 12 months postpartum

In our previous studies, one-third of lactating Guatemalan women, infants, and children had deficient or marginal serum vitamin B-12 concentrations. Relationships among maternal and infant status and breast milk vitamin B-12, however, have not, to our knowledge, been investigated in such populations. Our purpose was to measure breast milk vitamin B-12 in Guatemalan women with a range of serum vitamin B-12 concentrations and explore associations between milk vitamin B-12 concentrations and maternal and infant vitamin B-12 intake and status. Participants were 183 mother-infant pairs breastfeeding at 12 mo postpartum. Exclusion criteria included mother <17 y, infant <11.5 or >12.5 mo, multiple birth, reported health problems in mother or infant, and mother pregnant >3 mo. Data collected on mothers and infants included anthropometry, serum and breast milk vitamin B-12, and dietary vitamin B-12. Serum vitamin B-12 concentrations indicated deficiency (<150 pmol/L) in 35% of mothers and 27% of infants and marginal status (150-220 pmol/L) in 35% of mothers and 17% of infants. In a multiple regression analysis, breast milk vitamin B-12 concentration was associated (P < 0.05) with both maternal vitamin B-12 intake (r = 0.26) and maternal serum vitamin B-12 (r = 0.30). Controlling for the number of breastfeeds per day and vitamin B-12 intake from complementary foods, infant serum vitamin B-12 was associated with maternal serum vitamin B-12 (r = 0.31; P < 0.001) but not breast milk vitamin B-12, implicating a long-term effect of pregnancy status on infant vitamin B-12 status at 12 mo postpartum.     

Lactobacillus Bacteria in Breast Milk

Breast milk is an optimal food for infants and toddlers. The composition of breast milk adapts to the needs of the developing organism, satisfying nutritional needs at an early stage of growth and development. The results of research to date have shown that breast milk is the best food for a child, containing not only nutrients but also biologically active substances that aid in the optimal, proper growth and development of infants. Among the many components of breast milk, an important element is the probiotic microflora, including bacteria of the genus Lactobacillus spp. These organisms exert a multidirectional, health-promoting effect on the body of children who consume breast milk. The number of lactic acid bacteria, including Lactobacillus, colonizing the breast milk environment and their species diversity varies and depends on many factors, both maternal and environmental. Breast milk, as a recommended food for infants, is an important source of probiotic microflora. The aim of this study was to present the current understanding of probiotic bacteria of the genus Lactobacillus present in breast milk.