妊娠期妇女贫血状况调查分析

本文对259名正常初孕妇女的营养性贫血状况进行了调查分析。于不同孕期取血测定血清铁蛋白,红细胞原卟啉,血红蛋白,血清叶酸及血清维生素B_(12)含量。结果发现,孕妇体内铁缺乏、叶酸及维生素B_(12)不足随孕周增加日趋明显,至孕后期血清铁蛋白<12μg/L者达72.0％;红细胞原卟啉>500μg/L(全血)者占25.9％;血清叶酸<3μg/L者占32.1％;血清维生素B_(12)<150μg/L者为25.6％。259名孕妇中89名患有贫血,总患病率为34.4％。对89名贫血孕妇按缺铁性、叶酸缺乏,及铁和叶酸双缺进行分类,以缺铁性贫血为主,为61例(68.5％),叶酸缺乏贫血22例(28.1％),双缺者3例(3.4％)。不同孕期贫血的分类结果表明,缺铁性贫血随孕周增加所占比例逐渐下降;而叶酸缺乏贫血所占比例随孕周增加逐渐增高。     

孕妇血清中同型半胱氨酸、叶酸、维生素B_(12)的表达及临床价值分析

目的分析孕妇血清中同型半胱氨酸(HCY)、叶酸、维生素B_(12)的表达及临床价值。方法收集该院2014年8月-2016年2月收治的120例孕妇,分析孕妇血清HCY、叶酸与维生素B_(12)水平与不同临床指标的联系,并分析血糖、血压与孕妇HCY、叶酸、维生素B_(12)水平的相关性。结果年龄≥30岁者血清HCY水平高于30岁者,叶酸、维生素B_(12)水平低于30岁者(P0.05);早产者血清HCY水平高于非早产者,叶酸、维生素B_(12)水平低于非早产者(P0.05);伴妊娠期高血压者血清HCY水平高于非妊娠期高血压者,叶酸、维生素B_(12)水平低于非妊娠期高血压者(P0.05);妊娠期糖尿病者血清HCY水平高于非妊娠期糖尿病者,叶酸、维生素B_(12)水平低于非妊娠期糖尿病者(P0.05);早孕期者、中孕期者、晚孕期者血清HCY、叶酸、维生素B_(12)水平比较没有统计学差异(P0.05);孕妇血清HCY水平与血糖、舒张压、收缩压呈正相关,叶酸和维生素B_(12)水平与血糖、舒张压、收缩压呈负相关。结论孕妇血清HCY、叶酸、维生素B_(12)水平与年龄、早产、妊娠期并发症关系密切,及时有效的检测三者水平能够利于高危人群的识别,重视叶酸与维生素B_(12)的补充,可改善妊娠结局。     

25-羟维生素D 维生素B_(12)及叶酸对2～6岁孤独症谱系障碍儿童智力及核心症状的影响

目的分析25-羟维生素D[25(OH)D]、维生素B_(12)及叶酸对2～6岁孤独症谱系障碍(ASD)患儿智力及核心症状的影响。方法选取2019年1-12月湖北省妇幼保健院收治的2～6岁ASD患儿116例为观察组,另选取同期体检健康儿童116例为对照组,检测并比较两组儿童血清25(OH)D、维生素B_(12)及叶酸水平。观察组儿童采用中国韦氏幼儿智力量表第四版(WPPSI-Ⅳ)测定智力,采用孤独症评定量表(CARS)和孤独症行为量表(ABC)评估孤独症病情程度和症状;根据CARS评分将观察组分为轻中度组和重度组,比较不同组别儿童血清25(OH)D、维生素B_(12)及叶酸水平的差异;运用Pearson偏相关分析各指标与韦氏总智商和ABC评分的相关性。结果观察组患儿血清25(OH)D、维生素B_(12)及叶酸水平均明显低于对照组,且轻中度组高于重度组,差异均有统计学意义(均P0.01)。患儿血清25(OH)D、维生素B_(12)及叶酸水平与智力水平呈正相关关系(P0.01),与ABC量表评分均呈负相关关系(P0.05)。结论 ASD患儿的血清25(OH)D、维生素B_(12)及叶酸水平均下降,且与患儿的病情严重程度、智力及核心症状相关。     

叶酸、维生素B_(12)及同型半胱氨酸与阿尔茨海默病的相关性研究

目的研究阿尔茨海默病(Alzheimer’s disease,AD)和外周血中叶酸、维生素B_(12)以及同型半胱氨酸(homocysteine,Hcy)之间的关系,为开展叶酸等膳食维生素防治AD提供依据。方法于2012年11月至2017年11月选取来自天津脑系科专科医院认知障碍门诊的231例AD患者作为研究对象,选取天津市塘沽区某社区医院认知正常的230例老年人作为正常参照人群。收集基本信息,采集空腹静脉血测定血中叶酸、维生素B_(12)以及Hcy浓度。采用SPSS 17.0软件进行t检验、χ~2检验和多因素非条件logistic回归分析。结果 AD患者血中的叶酸、维生素B_(12)和Hcy浓度中位数(P_(25)~P_(75))分别为11.00 nmol/L(P_(25)~P_(75):7.16~16.10 nmol/L)、292.17 pmol/L(P_(25)~P_(75):202.82~406.53 pmol/L)和15.56μmol/L(P_(25)~P_(75):11.10~20.64μmol/L),叶酸和维生素B_(12)浓度均低于正常人群[14.74 nmol/L(P_(25)~P_(75):10.19~20.67 nmol/L)和381.81 pmol/L(P_(25)~P_(75):275.04~519.60 pmol/L)],Hcy浓度高于正常人群[11.75μmol/L(P_(25)~P_(75):8.66~15.63μmol/L)],差异均有统计学意义(P0.01)。AD患者血清叶酸过低、维生素B_(12)过低及Hcy过高的比例(分别为73.16%、8.66%和54.11%)均高于正常人群(分别为54.78%、3.91%和28.70%),差异均有统计学意义(P0.05,P0.01)。多因素logistic回归分析结果显示,调整混杂因素后,正常叶酸水平(OR=0.586)和正常维生素B_(12)水平(OR=0.079)者患AD的风险较低;高Hcy者患AD风险较高(OR=2.405),均有统计学意义(P0.05,P0.01)。结论叶酸、维生素B_(12)过低以及Hcy过高均与AD发病相关,针对老年人开展食品叶酸、维生素B_(12)强化可以在一定程度上防治或延缓AD的发生发展。     

维生素B_(12)与叶酸对辐射损伤的效应研究——四.大鼠的体重、白细胞数和死亡率

雄性大鼠分别全身一次照射800、850与875rad。分组在照射后不同时期注射或不注射抗菌素的条件下给与治疗剂量的维生素B_(12)和叶酸,其中有的组还给与大量的维生素C。主要结果为:(1)使用相当正常需要量200倍的维生素B_(12)和叶酸对于800rad照射后大鼠的死亡率、死亡动物活存日数和体重的影响与10倍量的维生素相比较并无明显差别,但是前者的第1～30天死亡率显著地较对照为低。(2)使用大量维生素C并未增加维生素B_(12)和叶酸对850rad所致急性辐射损伤的疗效。(3)850rad照射后使用抗菌素并在第7～25日使用大量的维生素B_(12)与叶酸对大鼠体重恢复的效应比单用抗菌素或维生素为佳。(4)在800,850与875rad照射后不同时期使用大量的维生素B_(12)和叶酸不能显著降低第1～40天的死亡率,但是在体重、白细胞数与死亡动物活存日数的方面,照射后不同时期使用大量维生素B_(12)和叶酸的效果是不同的,如800与850rad照射后第7～25日给与维生素B_(12)和叶酸的大鼠体重恢复程度较第1～25日给与维生素的大鼠为高;875rad照射后第1～25日给与维生素B_(12)和叶酸,其死亡动物的活存日数较第7～25日或第15～25日给与维生素的大鼠为少,而且第15～25日给与维生素B_(12)和叶酸的大鼠白细胞恢复程度较第1～25日或第7～25日给与维生素的     

母亲维生素B_(12)缺乏与婴儿继发性甲基丙二酸尿症

目的探讨母亲维生素B_(12)缺乏导致的婴儿继发性甲基丙二酸尿症(MMA)的临床特点,以及该病的诊断、治疗及转归。方法选择2014年11月12日,因"吐奶、贫血、疑为遗传性MMA",于北京大学第一医院被确诊为因母亲维生素B_(12)缺乏导致的继发性MMA、日龄为27d的男性双胎新生儿为研究对象。对双胎患儿及其母亲进行血常规、血清维生素B_(12)与叶酸检测,以及血清与尿液总同型半胱氨酸检测,尿液有机酸谱及血液氨基酸、肉碱谱检测,同时检测患儿及其父母的MMA相关基因突变情况。本研究与2例受试者监护人签署临床研究知情同意书,本研究遵循的程序通过北京大学第一医院医学伦理委员会的审核批准。结果 12例患儿生后4d于当地医院就诊时,尿液甲基丙二酸浓度分别为479.21 mmol/mol肌酐和65.90 mmol/mol肌酐(正常参考值为0.20~3.60mmol/mol肌酐);血液丙酰肉碱浓度分别为12.01μmol/L和10.55μmol/L(正常参考值为1.00~5.00μmol/L)。生后27d于北京大学第一医院就诊时发现,2例患儿均存在中度贫血,长子血清总同型半胱氨酸浓度轻度增高,为17.6μmol/L(正常参考值为0~15.0μmol/L),次子正常,为14.3μmol/L;血清维生素B_(12)浓度均降低,分别为121.0pmol/L与105.0pmol/L(正常参考值为133.0~675.0pmol/L);血清叶酸浓度均正常,分别为26.50nmol/L与18.60nmol/L(正常参考值为6.80nmol/L);尿液中均未检出甲基丙二酸,血液丙酰肉碱均增高,分别为9.26μmol/L与15.90μmol/L。给予维生素B_(12)肌内注射,口服亚叶酸钙及左卡尼汀治疗后,2例患儿尿液中均未检出甲基丙二酸,血液丙酰肉碱浓度恢复正常,智力、运动发育正常,贫血好转。22例患儿母亲于早孕期出现厌食、呕吐等早孕期妊娠反应,中孕期出现糖尿病、甲状腺功能减低、大细胞性贫血及同型半胱氨酸血症,曾口服补血中药及铁剂治疗,未曾补充维生素B_(12)治疗。产后2个月时,母亲血清维生素B_(12)浓度降低,血清总同型半胱氨酸浓度升高。经左卡尼汀、甲钴胺、叶酸等营养干预治疗2个月后,母亲血清维生素B_(12)及总同型半胱氨酸浓度均恢复正常。3对于与遗传性MMA相关基因的检测结果显示,2例患儿及其父母均未见MUT、MMAA、MMAB、MMACHC等基因突变。结论母亲孕期营养不良及健康状况不佳,可导致维生素B_(12)缺乏,继而引起婴儿继发性MMA。临床注意对继发性MMA患者与遗传性MMA的早期鉴别诊断,并于确诊后及时给予维生素B_(12)治疗,是救治继发性MMA,改善其预后的关键。对于妊娠期贫血的母亲,更应注意维生素B_(12)缺乏的可能性,以免导致婴儿罹患继发性MMA。     

维生素B_(12)与叶酸水平检测在二甲双胍治疗妊娠期糖尿病中的临床意义

目的探讨维生素B_(12)与叶酸水平检测在二甲双胍治疗妊娠期糖尿病中的临床意义。方法选取2017年2月-2018年2月深圳市龙华区人民医院收治的120例妊娠期糖尿病患者为研究组,另选取同期在该院产检的50例正常妊娠孕妇为对照组。入组后次日及二甲双胍治疗8周后采集空腹静脉血3 ml检测血清维生素B_(12)与叶酸水平。统计不良妊娠结局的发生率。结果研究组治疗前后血清维生素B_(12)与叶酸水平均显著低于对照组,差异均有统计学意义(均P0. 05)。研究组治疗后血清维生素B_(12)与叶酸水平均显著低于治疗前,差异均有统计学意义(均P0. 05)。B_(12)高水平组、B_(12)中水平组,叶酸高水平组、叶酸中水平组剖宫产、蛋白尿症、体质量增加、子痫前期发生率明显低于B_(12)低水平组和叶酸低水平组,差异均有统计学意义(均P0. 05)。叶酸低水平及B_(12)低水平与不良妊娠结局密切相关(P0. 05)。结论二甲双胍长期治疗可导致血清维生素B_(12)和叶酸水平下降,血清维生素B_(12)及叶酸水平越低产妇不良事件发生率越高,值得临床重视。     

PHGF联合酚妥拉明治疗慢性重症病毒性肝炎84例疗效分析

1 对象和方法1.1 对象全部病例均符合1990年(上海)第六次全国病毒性肝炎学术会议修订的诊断标准。血清胆红素(SB)均>345mmol/L。84例患者中,男60例,女24例;年龄14岁～77岁,60岁以上15例,平均年龄43岁。全部病例均有程度不同的消化道症状及凝血酶原时间(PT,正常值13S)均延长4S以上,其中36例延长达正常值的一倍以上。肝促凝血活酶(HPT,正常值80%以上)<30%占30例。血清白蛋白(A)均<40g/L,其中36例<30g/L。尿素氮(BUN)>7.2mmol/L30     

孕妇稳定补充叶酸后的血清叶酸水平及其影响因素分析

目的探讨稳定补充叶酸后,孕妇血清叶酸水平及其影响因素。方法选择2019年8月至2020年12月,于复旦大学妇产科医院进行产前检查,并且在正常饮食情况下稳定补充叶酸(400μg/d×60 d)后的718例孕龄为12~24孕周孕妇为研究对象。根据补充叶酸后的血清叶酸水平,将其分为4组:A组(n=23,血清叶酸水平<7 ng/mL),B组(n=170,血清叶酸水平为≥7~14 ng/mL),C组(n=217,血清叶酸水平为≥14~18 ng/mL),D组(n=308,血清叶酸水平为≥18~20 ng/mL)。采用χ^(2)检验及秩和检验,对4组孕妇一般临床资料及血清维生素B12水平、同型半胱氨酸(Hcy)浓度进行统计学比较(单因素分析)。对孕妇稳定补充叶酸后上述4个血清叶酸水平的影响因素,采用无序多分类logistic回归法进行分析。本研究遵循的程序符合2013年修订的《世界医学协会赫尔辛基宣言》。获取所有受试者的知情同意,并与其签署临床研究知情同意书。结果①单因素分析结集显示:4组孕妇血清Hcy浓度、维生素B12水平,孕龄≥12~19孕周与≥19~25孕周构成比比较,差异均有统计学意义(均为P<0.001)。②相对于血清叶酸水平为<7 ng/mL:孕妇血清Hcy浓度每增加1μmol/L,血清叶酸水平为≥7~14 ng/mL、≥14~18 ng/mL、≥18~20 ng/mL的可能性分别降低到原来的0.731倍(OR=0.731)、0.353倍(OR=0.353)、0.471倍(OR=0.471);孕妇血清维生素B12水平每增加1 pg/mL,血清叶酸水平为≥14~18 ng/mL的可能性增加到原来的1.004倍(OR=1.004)。③相对于血清叶酸水平为≥7~14 ng/mL:孕妇血清Hcy浓度每增加1μmol/L,血清叶酸水平为<7 ng/mL、≥14~18 ng/mL、≥18~20 ng/mL的可能性分别为增加到原来的1.369倍(OR=1.369)、降低到原来的0.483倍(OR=0.483)、降低到原来的0.644倍(OR=0.644);孕妇血清维生素B12水平每增加1 pg/mL,血清叶酸水平为≥14~18 ng/mL、≥18~20 ng/mL的可能性分别增加到原来的1.003倍(OR=1.003)、1.003倍(OR=1.003);孕龄≥12~19孕周孕妇血清叶酸水平为≥18~20 ng/mL的可能性是孕龄≥19~25孕周孕妇的2.244倍(OR=2.244)。④相对于血清叶酸水平为≥14~18 ng/mL:孕妇血清Hcy浓度每增加1μmol/L,血清叶酸水平为<7 ng/mL、≥7~14 ng/mL、≥18~20 ng/mL的可能性均分别增加到原来的2.832倍(OR=2.832)、2.069倍(OR=2.069)、孕妇1.333倍(OR=1.333);孕妇血清维生素B12水平每增加1 pg/mL,血清叶酸水平为<7 ng/mL、≥7~14 ng/mL的可能性均降低到原来的0.996倍(OR=0.996)、0.997倍(OR=0.997)。结论血清Hcy浓度及维生素B12水平,以及孕龄,均对孕妇稳定补充叶酸后的血清叶酸水平有影响:血清Hcy浓度主要为负向影响,血清维生素B12水平主要为正向影响,孕龄仅对血清叶酸水平较高级别有影响。     

检测血清同型半胱氨酸、叶酸及维生素B12在妊娠期高血压疾病的临床意义

目的:探讨检测血清同型半胱氨酸(Hcy)、叶酸和维生素B_(12)在妊娠期高血压疾病的临床价值。方法:回顾性收集2017年4月—2019年10月本院收治并确诊的143例妊娠期高血压疾病患者,按照疾病类型分为妊娠期高血压组50例、轻度先兆子痫组48例、重度先兆子痫组45例。另选健康孕妇40例为健康孕妇组和非妊娠健康女性35例为对照组。检测并比较所有组别的血清同型半胱氨酸、叶酸及维生素B_(12)水平,并采用受试者工作特征曲线(ROC)分析3个指标诊断妊娠期高血压疾病效能,logistic回归分析影响妊娠期高血压疾病孕妇妊娠结局的危险因素。结果:与对照组和健康孕妇组比较,妊娠期高血压、轻度子痫和重度子痫组的同型半胱氨酸依次增高,叶酸及维生素B_(12)依次降低(P0.05),同型半胱氨酸与叶酸及维生素B_(12)呈负相关关系(P0.05),叶酸与维生素B_(12)呈正相关关系(P0.05)。血清同型半胱氨酸、叶酸、维生素B_(12)均可用于诊断妊娠期高血压疾病,且联合诊断效能最高(P0.05)。与不良妊娠结局比较,妊娠结局良好组孕妇血清同型半胱氨酸增高,叶酸及维生素B_(12)降低(P0.05)。同型半胱氨酸、叶酸及维生素B_(12)是妊娠期高血压疾病孕妇不良妊娠结局的独立影响因素(P0.05)。结论:血清同型半胱氨酸、叶酸和维生素B_(12)联合诊断妊娠期高血压疾病效能高于单独指标检测,高水平的同型半胱氨酸、低水平的叶酸和维生素B_(12)预示着妊娠期高血压疾病孕妇不良妊娠结局。     

Declining rate of folate insufficiency among adults following increased folic acid food fortification in Canada

OBJECTIVE: Canada introduced a mandatory folic acid food fortification program in November 1998. We investigated whether the rate of folate and vitamin B12 insufficiency among adults has changed since this mandatory fortification program was implemented. METHODS: We conducted a retrospective cross-sectional study using a large Ontario laboratory database. We included all individuals who underwent evaluation of their serum folate, red cell folate and serum vitamin B12 between April 1, 1997 to July 31, 1998 (Period A), August 1, 1998 to January 30, 1999 (Period B) and February 1, 1999 to March 31, 2000 (Period C). RESULTS: A total of 8,884 consecutive samples were analyzed during the period of study. Mean age was 57.4 years (SD 21.1), and 63.2% were female. The prevalence of serum folate insufficiency (below 3.4 nmol/L) fell from 0.52% in Period A to 0.22% in Period C [prevalence ratio (RR) 0.41, 95% confidence interval (CI) 0.18-0.93)]. The prevalence of red cell folate insufficiency (below 215 nmol/L) declined from 1.78% during Period A to 0.41% in Period C (RR 0.23, 95% CI 0.14-0.40). No significant difference was observed between periods in the prevalence of B12 insufficiency below 120 pmol/L (3.93% versus 3.11%, respectively; RR 0.79, 95% CI 0.62-1.01). CONCLUSIONS: There has been a significant decline in the prevalence of folate, but not vitamin B12 insufficiency, following Canadian folic acid food fortification. These changes may have important implications for the prevention and detection of folate and vitamin B12 insufficiency, including identifying the benefits of folic acid food fortification and the need to further consider fortification or supplementation with vitamin B12.     

Prevalence of low serum folate and vitamin B12 in an older Australian population

OBJECTIVE: To examine the prevalence of low serum folate and vitamin B12, in association with elevated serum homocysteine, in a representative sample of older Australians. METHODS: During 1997-2000, 3,508 persons aged 50+ years were examined in a population-based cohort study conducted in two postcodes, west of Sydney, Australia. Of these, 2,901 participants (82.7%) provided fasting blood for estimates of serum folate, vitamin B12 and total homocysteine. RESULTS: Low serum B12 (< 185 pmol/L) was found in 22.9% of participants and low serum folate (< 6.8 nmol/L) in 2.3% of participants. Among those people with very low serum vitamin B12 (< 125 pmol/L) and low serum folate, 51% had elevated homocysteine. CONCLUSIONS: Low serum levels of vitamin B12 and elevated serum homocysteine are relatively frequent in older Australians. IMPLICATIONS: Appropriate public health action should be considered to reduce the prevalence of low serum vitamin B12 and elevated homocysteine in older Australians.     

Biochemical indicators of B vitamin status in the US population after folic acid fortification: results from the National Health and Nutrition Examination Survey 1999-2000

BACKGROUND: Mandatory folic acid fortification of cereal-grain products was introduced in the United States in 1998 to decrease the risk that women will have children with neural tube defects. OBJECTIVE: The objective was to determine the effect of folic acid fortification on concentrations of serum and red blood cell (RBC) folate, serum vitamin B-12, and plasma total homocysteine (tHcy) and methylmalonic acid (MMA) in the US population. DESIGN: Blood was collected from a nationally representative sample of approximately 7300 participants aged > or = 3 y in the National Health and Nutrition Examination Survey (NHANES) during 1999-2000 and was analyzed for these B vitamin-status indicators. The results were compared with findings from the prefortification survey NHANES III (1988-1994). RESULTS: The reference ranges (5th-95th percentiles) were 13.1-74.3 nmol/L for serum folate, 347-1167 nmol/L for RBC folate, and 179-738 pmol/L for serum vitamin B-12. For plasma tHcy and MMA, the reference ranges for serum vitamin B-12-replete participants with normal serum creatinine concentrations were 3.2-10.7 mumol/L and 60-210 nmol/L, respectively. The prevalence of low serum folate concentrations (<6.8 nmol/L) decreased from 16% before to 0.5% after fortification. In elderly persons, the prevalence of high serum folate concentrations (>45.3 nmol/L) increased from 7% before to 38% after fortification; 3% had marginally low serum vitamin B-12 concentrations (<148 pmol/L) and 7% had elevated plasma MMA concentrations (>370 nmol/L). Seventy-eight percent of the US population had plasma tHcy concentrations <9 micromol/L. CONCLUSIONS: Every segment of the US population appears to benefit from folic acid fortification. Continued monitoring of B vitamin concentrations in the US population is warranted.     

Age-related hearing loss, vitamin B-12, and folate in elderly women

BACKGROUND: Hearing impairment is 1 of the 4 most prevalent chronic conditions in the elderly. However, the biological basis of age-related hearing loss is unknown. OBJECTIVE: The objective was to test the hypothesis that age-related hearing loss may be associated with poor vitamin B-12 and folate status. DESIGN: A thorough audiometric assessment was conducted in 55 healthy women aged 60-71 y. Hearing function was determined by the average of pure-tone air conduction thresholds at 0.5, 1, 2, and 4 kHz and was categorized into 2 groups for logistic regression analyses: normal hearing (<20 dB hearing level; n = 44) and impaired hearing (> or = 20 dB hearing level; n = 11). RESULTS: Mean age was the same (65 y) for the normal hearing and impaired hearing groups. Pure-tone averages were inversely correlated with serum vitamin B-12 (r = -0.58, P = 0.0001) and red cell folate (r = -0.37, P = 0.01). Women with impaired hearing had 38% lower serum vitamin B-12 (236 compared with 380 pmol/L, respectively, P = 0.008) and 31% lower red cell folate (425 compared with 619 nmol/L, respectively, P = 0.02) than women with normal hearing. Among participants who did not take supplements containing vitamin B-12 or folate, women with impaired hearing had 48% lower serum vitamin B-12 (156 compared with 302 pmol/L, respectively, P = 0.0007) and 43% lower red cell folate (288 compared with 502 nmol/L, respectively, P = 0.001) than women with normal hearing. CONCLUSION: Poor vitamin B-12 and folate status may be associated with age-related auditory dysfunction.     

Genetic, dietary, and other lifestyle determinants of serum homocysteine levels in young adults in Costa Rica.

OBJECTIVE: Elevated serum total homocysteine (tHcy) is considered an independent risk factor for cardiovascular disease. The objective of this study was to develop the first-ever information on the prevalence of hyperhomocysteinemia and its determinants in a population in Costa Rica. METHODS: A cross-sectional study was conducted to determine serum levels of tHcy, vitamin B(12), folate, and creatinine, as well as the presence of the genotype TT for the methylenetetrahydrofolate reductase (MTHFR) enzyme. Additionally, dietary vitamin intakes and other lifestyle risk factors were assessed. A total of 399 Costa Rican adults from the central valley of the country (where the capital city, San José, is located), aged 20 to 40 years, participated in this study in the year 2000. Analyses of variance were performed for continuous variables, and the chi-square test was used for categorical data. Spearman correlation tests were calculated to determine associations between variables. Three linear regression analyses and one binary logistic model were developed in order to determine the predictors for homocysteine levels in the population studied. RESULTS: The overall prevalence of hyperhomocysteinemia (>15 micromol/L) in the population was 6%, 31% of the population were in the range of 10 to 15 micromol/L, 29% had the genotype TT for the enzyme MTHFR, 18% presented a vitamin B(12) deficiency (<165 pmol/L), and none of the persons had low serum folate levels (<7.0 nmol/L). No significant associations were found between tHcy and age, smoking, consuming alcohol, or dietary vitamin intake. CONCLUSIONS: Only serum vitamin B(12) levels and the genotype TT of the enzyme MTHFR were considered significant predictors of high serum tHcy levels in the Costa Rica population studied.     

Vitamin B-12 status is associated with socioeconomic level and adherence to an animal food dietary pattern in Colombian school children

Vitamin B-12 is related to neurocognitive function in school-age children, yet sociodemographic and dietary correlates of vitamin B-12 status in this age group are not well characterized. The prevalences of vitamin B-12 or folate deficiencies in Colombia are unknown. We conducted a cross-sectional study in a representative sample of 2800 low- and middle-income children aged 5-12 y from Bogotá's public schools. Plasma vitamin B-12 and erythrocyte folate concentrations (mean +/- SD) were 327 +/- 106 pmol/L and 858 +/- 256 nmol/L, respectively. The prevalence of vitamin B-12 deficiency (<148 pmol/L) was 1.6% and the prevalence of marginal status (148-221 pmol/L) was 15.0%. Only 2 children had folate deficiency (<305 nmol/L). In multivariate analysis, mean vitamin B-12 concentrations significantly decreased with age and were 15 pmol/L higher in girls than boys (95%CI = 8, 23). Vitamin B-12 was inversely related to the mother's parity and positively associated with the amount of money spent on food per person per day at home and the household's neighborhood socioeconomic status (SES) classification. Folate concentrations were lower in girls than in boys and significantly increased with the household's SES. We identified 4 dietary patterns with principal components analysis of a FFQ in a random subsample (n = 972). Plasma vitamin B-12 was strongly, positively associated with a pattern that included frequent intake of beef, chicken, and dairy products in a dose-response manner (P-trend, adjusted, = 0.008). Low vitamin B-12 status is not negligible in Colombian school children and is associated with poverty and marginal intake of animal food sources.     

The Chilean flour folic acid fortification program reduces serum homocysteine levels and masks vitamin B-12 deficiency in elderly people

Hyperhomocysteinemia is considered a risk factor for cardiovascular disease and is prevalent in the elderly. Supplementation with folic acid, vitamin B-6 and B-12 lowers homocysteine levels. In January 2000, the Chilean government initiated a flour folic acid fortification program to decrease the occurrence of neural tube defects. The aim of this study was to evaluate the effect of this program on serum homocysteine and folate levels in elderly subjects after 6 mo. A total of 108 elderly people were studied. We measured serum folate, homocysteine and vitamin B-12 levels before the fortification started and 6 mo later. At baseline, folate deficiency (<6.8 nmol/L) was present in 1.8%, vitamin B-12 deficiency (<165 pmol/L) in 27.6% and hyperhomocysteinemia (>14 micromol/L) in 31% of the sample. Six months later, serum folate levels increased from 16.2 +/- 6.2 to 32.7 +/- 7.1 nmol/L (P < 0.001), homocysteine levels decreased from 12.95 +/- 3.7 to 11.43 +/- 3.6 micromol/L (P < 0.001) and vitamin B-12 levels were unchanged. Flour fortification with folic acid had a moderate lowering effect on homocysteine levels. Given that vitamin B-12 deficiency was more common than folate deficiency, it may be more appropriate to add vitamin B-12 to food, at least in foods for this age group.     

Maternal total homocysteine concentration and neonatal size in India

The smallness of Indian babies is ascribed to small maternal size and their chronic under nutrition. Micronutrient nutrition of the mother may be particularly important. We investigated the relationship between maternal circulating concentrations of total homocysteine (tHcy), vitamin B12 and folate and offspring size at birth. Mothers of full term small for gestation age babies (SGA, gestation and sex specific birth weight <10th centile, N = 30) and mothers of appropriate for gestational age babies (AGA, >10th centile, N = 50) were compared for their body size, plasma tHcy, vitamin B12 and red cell folate concentration at 28 week gestation. Mothers of SGA babies were lighter and shorter than those of AGA babies (P <0.05, both) and had higher plasma tHcy concentration (P<0.01). Total homocysteine concentrations were inversely related to plasma vitamin B12 and red cell folate concentrations (r = approximately -0.5, P <0.01, both). Seventy percent of the women had a low vitamin B12 status (plasma vitamin B12 <150 pmol/L) but none were folate deficient (red cell folate <283 nmol/L). Higher maternal plasma tHcy concentration was significantly associated with lower offspring birth weight (r = -0.28, P<0.05 adjusting for maternal height, weight, gestation at delivery and the baby's gender), this effect was reduced by adjustment for red cell folate concentration. We conclude that maternal vitamin B12 deficiency reflected in plasma tHcy concentration contributes to small size of Indian babies.     

Dietary Intake and Status of Vitamin B12 in Slovenian Population

Vitamin B12 deficiency poses a health concern, especially in vulnerable populations. Dietary vitamin B12 intake was obtained by two 24 h dietary recalls and food propensity questionnaires in a representative Slovenian cross-sectional food consumption survey, SI.Menu (n = 1248 subjects; 10–74 years). For a subgroup of 280 participants, data on serum vitamin B12 were available through the Nutrihealth study. The estimated usual population-weighted mean daily vitamin B12 intakes were 6.2 µg (adults), 5.4 µg (adolescents), and 5.0 µg (elderly). Lower intakes were observed in females. Inadequate daily vitamin B12 intake (<4 µg) was detected in 37.3% of adolescents, 31.7% of adults, and 58.3% elderlies. The significant predictors for inadequate daily vitamin B12 intake were physical activity score in all age groups, sex in adolescents and adults, financial status and smoking in elderly, and employment in adults. Meat (products), followed by milk (products), made the highest vitamin B12 contribution in all age groups. In adolescents, another important vitamin B12 contributor was cereals. The mean population-weighted serum vitamin B12 levels were 322.1 pmol/L (adults) and 287.3 pmol/L (elderly). Low serum vitamin B12 concentration (<148 nmol/L) and high serum homocysteine (>15 µmol/L) were used as criteria for vitamin B12 deficiency. The highest deficiency prevalence was found in elderlies (7.0%), particularly in males (7.9%). Factors associated with high serum homocysteine were also investigated. In conclusion, although vitamin B12 status was generally not critical, additional attention should be focused particularly to the elderly.     

Folate and vitamin B12 status in relation to cognitive impairment and anaemia in the setting of voluntary fortification in the UK

Concerns about risks for older people with vitamin B12 deficiency have delayed the introduction of mandatory folic acid fortification in the UK. We examined the risks of anaemia and cognitive impairment in older people with low B12 and high folate status in the setting of voluntary fortification in the UK. Data were obtained from two cross-sectional studies (n 2403) conducted in Oxford city and Banbury in 1995 and 2003, respectively. Associations (OR and 95 % CI) of cognitive impairment and of anaemia with low B12 status (holotranscobalamin < 45 pmol/l) with or without high folate status (defined either as serum folate >30 nmol/l or >60 nmol/l) were estimated after adjustment for age, sex, smoking and study. Mean serum folate levels increased from 15.8 (sd 14.7) nmol/l in 1995 to 31.1 (sd 26.2) nmol/l in 2003. Serum folate levels were greater than 30 nmol/l in 9 % and greater than 60 nmol/l in 5 %. The association of cognitive impairment with low B12 status was unaffected by high v. low folate status (>30 nmol/l) (OR 1.50 (95 % CI 0.91, 2.46) v. 1.45 (95 % CI 1.19, 1.76)), respectively. The associations of cognitive impairment with low B12 status were also similar using the higher cut-off point of 60 nmol/l for folate status ((OR 2.46; 95 % CI 0.90, 6.71) v. (1.56; 95 % CI 1.30, 1.88)). There was no evidence of modification by high folate status of the associations of low B12 with anaemia or cognitive impairment in the setting of voluntary fortification, but periodic surveys are needed to monitor fortification.