叶酸、维生素B_6、B_(12)对局灶性脑缺血大鼠血浆同型半胱氨酸水平和抗氧化作用的研究

目的:研究叶酸(FA)、维生素B6(VB6)和维生素B12(VB12)对局灶性脑缺血大鼠血浆同型半胱氨酸(homocysteine,Hcy)水平和抗氧化作用。方法:SD大鼠随机分为假手术组(Sham)、大脑中动脉闭塞模型组(MCAO)、MCAO+FA组和MCAO+FA+VB6+VB12组(MCAO+CV)。后三组均经手术造成MCAO模型,维生素补充前、补充28d后和手术后24h分别检测大鼠血浆Hcy浓度及血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(MDA)含量,缺血后检测脑组织抗氧化指标。结果:补充FA、VB6和VB12后及缺血后,MCAO+FA组和MCAO+CV组血浆Hcy均低于Sham组和MCAO组,且MCAO+CV组低于MCAO+FA组;MCAO+FA组和MCAO+CV组血清或脑组织SOD和GSH-Px活性均高于MCAO组,MDA含量低于MCAO组。结论:补充FA、VB6和VB12能降低血浆Hcy浓度,提高机体抗氧化能力,减轻脑缺血造成的氧化应激损伤。     

叶酸联合维生素B6/B12心对脑缺血半暗带区影响

目的 研究叶酸(FA)、维生素B6(VB6)和维生素B12(VB12)对局灶性脑缺血-中脑动脉闭塞(MCAO)大鼠缺血半暗带区(ischemie penumbra,IP)的影响.方法 将SD大鼠随机分为中脑动脉闭塞模型组(MCAO)、MCAO+叶酸组(MCAO+FA)和MCAO+复合维生素(叶酸+VB6+VB12)组(MCAO+CV);预防性给药28 d后,手术制备各组大鼠大脑中动脉闭塞(MCAO)模型,造成局灶性脑缺血,对脑部进行磁共振(MRI)扫描,观察预防性给予叶酸及其联合VB6及VB12,对缺血半暗带区的改善效果.结果 缺血后6 h,半暗带区表观弥散系数(ADC):MCAO+FA组为0.61±0.04,MCAO+CV组为0.63±0.04,均高于MCAO组的0.50±0.05(P<0.05),2组平均弥散系数(DCavg)依次为0.74±0.04,0.77±0.06,均高于MCAO组的0.67±0.04(P<0.05),MCAO组部分各向异性值(FA)为0.80±0.06,高于MCAO组的0.62±0.04(P<0.05).结论 补充叶酸能使脑缺血半暗带区向正常灌注区发展,抑制缺血核心区的扩大,联合补充VB6和VB12效果更佳.     

血浆同型半胱氨酸与急性脑梗死关系的临床研究

目的探讨血浆同型半胱氨酸（Hcy）与急性脑梗死的关系及其临床意义。方法86例急性脑梗死患者（急性脑梗死组）和同期66例体检正常的健康者（对照组）采用荧光偏振免疫分析法测定血浆Hcy，采用化学发光法测定叶酸和维生素B12，并将结果进行比较。结果急性脑梗死组血浆Hcy为（20．08±8．72）μmol／L，对照组为（12．50±2．20）μmol／L，两组比较差异有统计学意义（P〈0．01）；急性脑梗死组血浆叶酸为（4．98±5．01）μg／L，对照组为（7．68±2．02）μg／L，两组比较差异有统计学意义（P〈0．01）；急性脑梗死组血浆维生素B12为（227．39±127．89）pmol／L，对照组为（311．64±152．15）pmol／L，两组比较差异有统计学意义（P〈0．01）。结论急性脑梗死患者血浆Hcy是升高的，而血浆叶酸和维生素B12呈下降趋势，Hcy是急性脑梗死的独立危险因素。     

原发性高血压患者补充适量的叶酸、维生素B12对其治疗效果影响的临床研究

目的探讨原发性高血压患者给予叶酸及维生素B12治疗前后血浆同型半胱氨酸（Hcy）、不对称二甲基精氨酸（ADMA）,血清一氧化氮（NO）及内皮性一氧化氮合酶（eNOS）水平的变化。方法选取156例原发性高血压患者为研究对象,按随机数字表法分成两组,每组78例。对照组给予常规降压治疗,试验组在对照组治疗的基础上给予口服叶酸及维生素B12,比较两组治疗前后Hcy、ADMA、NO及eNOS水平的变化。结果对照组治疗后2、12周Hcy及ADMA水平与治疗前比较差异无统计学意义（P〉0．05）;试验组治疗后2、12周Hcy、ADMA水平较治疗前显著降低,差异有统计学意义（P〈0．05）。治疗后12周,试验组NO、eNOS水平高于对照组[（77．35±9．55）拉mol／L比（64．26±11．49）μmol／L、（30．05±6．88）μmol／L比（19．92±10．24）μmol/L],差异有统计学意义（P〈0．05）。原发性高血压患者ADMA水平与Hcy水平呈正相关（r=0．612,P〈0.05）,与NO和eNOS水平呈负相关（r=-0．557、-O．529,P〈0．05）。结论原发性高血压患者适当补充叶酸及维生素B12可降低血液中Hcv和ADMA的水平,升高NO、eNOS水平,改善患者血管内皮细胞功能,并可辅助降低血压,有利于预防心脑血管意外的发生。     

脑卒中患者血浆同型半胱氨酸水平变化及临床意义

目的：探讨脑卒中患者血浆同型半胱氨酸（Hcy）水平及影响Hcy的因素。方法：选取2013年1月-2014年3月在本院住院治疗的脑卒中和同期体检的健康人作为研究对象,分为脑出血组、脑梗死组和对照组,比较三组人群Hcy、叶酸等指标的水平差异,探讨脑卒中发病、神经缺损程度与Hey的关系。结果：脑出血组和脑梗死组的Hcy水平高于对照组,叶酸、维生素B12：水平低于对照组,差异均有统计学意义（P〈0．05）;脑卒中患者体内的Hey水平与叶酸和维生素B12水平呈负相关;Hcy每上升1μmol／L,发生脑卒中的风险上升11．8％;Hev每上升1μmol／L,神经功能缺损程度评分上升3．124分。结论：高Hcy水平是脑卒中的独立危险因素,Hcv水平与叶酸、维生素B12呈负相关,能反映神经功能缺损程度。     

原发性高血压应用不同干预方案前后血浆同型半胱氨酸及不对称二甲基精氨酸变化意义分析

目的探讨原发性高血压患者应用不同干预方案前后血浆同型半胱氨酸（Hcy）及不对称二甲基精氨酸（ADMA）变化的临床意义。方法选择2009年2月至2013年2月收治的原发性高血压患者150例,按随机数字表法分为三组,每组50例。A组给予常规降压治疗,B组在A组治疗的基础上给予叶酸＋维生素B。C组在B组治疗的基础上给予普罗布考500mg,2次/d。观察三组治疗前、治疗后2周及治疗后12周Hcy、ADMA水平及血压的变化情况。结果A组治疗后2、12周Hcy、ADMA水平与治疗前比较差异无统计学意义（P〉0．05）;B组治疗后12周Hcy、ADMA水平较治疗前、治疗后2周明显降低,差异有统计学意义（P〈0．05）;C组治疗后2、12周Hcy[（14．94±5．13）、（10．91±3．85）μmol／L]、ADMA[（0．17±0．08）、（0．12±0．05）μmol／L]水平均较治疗前[（22．42±9．28）μmol／L和（0．21±0．12）μmol／L]明显降低,且与A、B组同期比较明显降低,差异均有统计学意义（P〈0．05）。A组治疗前后收缩压比较差异无统计学意义（P〉0．05）;B、C组治疗后12周收缩压较本组治疗前及同期A组明显降低,差异均有统计学意义（P〈0．05）。Pearson直线相关性分析表明,ADMA与Hcy呈正相关（r=0．557,P〈0．05）。结论给予原发性高血压患者补充适量的叶酸、维生素B12和普罗布考能有效降低Hcy、ADMA水平,进一步改善原发性高血压患者的血管内皮细胞功能,兼有辅助降压作用,有助于预防心脑血管事件。     

叶酸、VB_6、VB_(12)体外对同型半胱氨酸致主动脉内皮细胞损伤的保护作用

目的:观察叶酸(FA)、VB6、VB12对同型半胱氨酸(Hcy)致血管内皮细胞损伤的交互保护作用。方法:原代培养大鼠主动脉内皮细胞(RAEC),根据正交分析结果分为6组,阴性对照组、阳性对照组(Hcy)、维生素对照组(FA+VB6+VB12)及三组维生素防护组(Hcy+FA,Hcy+FA+VB12,Hcy+FA+VB6+VB12),维生素用含终浓度为1.0mmol/L Hcy的培养基配制。干预24 h后,取上清液,通过MTT细胞增殖实验比较各组SOD、GSH-PX、MDA、NO、NOS等指标的差异。结果:叶酸与VB12能缓解1.0mmol/L Hcy对RAEC增殖的抑制作用,而VB6则无明显效果。叶酸与VB6无交互作用,与VB12存在交互作用;VB6与VB12之间也存在交互作用;FA、FA+VB12、FA+VB6+VB12三种组合均能拮抗Hcy对SOD、GSH-PX、NOS酶活性的抑制作用,保护内皮细胞功能。结论:同时补充叶酸、VB6、VB12可能是三者在体外保护Hcy损伤内皮的较理想组合。     

α-硫辛酸对甲基汞致大鼠脑谷氨酸代谢转运障碍的拮抗作用

[目的]探讨出硫辛酸（alpha—lipoicacid,α-LA）对甲基汞所致大鼠脑谷氨酸代谢转运障碍的拮抗作用。[方法]清洁级Wistar大鼠24只,按体重随机分为4组,分别为对照组,低、高甲基汞染毒组和α-LA干预组,每组6只,雌雄各半。对照组和低、高甲基汞染毒组先皮下注射0．9％氯化钠溶液,α-LA干预组皮下注射35gmol／kgct-LA;2h后,对照组腹腔注射0．9％氯化钠溶液,低、高甲基汞染毒组和α-LA干预组分别腹腔注射氯化甲基汞4、12和12lamol／kg。α-LA预处理隔日1次;染毒组每日1次,每周5次;连续处理4周。最后1次染毒24h后,分离大鼠大脑皮质,制备5％、10％的组织匀浆,测定大脑皮质汞（Hg）、谷氨酸（Glu）、谷氨酰胺（Gin）含量,及谷氨酰胺酶（PAG）、谷氨酰胺合成酶（GS）、Na＋-K＋ATPase、Ca2＋．ATPase活力。[结果]甲基汞高剂量染毒组大鼠脑汞为（17．72±1．36）μg,／g组织、Glu含量为（71．57±10．87）μmol／g白、PAG活力为（31．26±4．38）μmol／（min·g蛋白）,均高于对照组（P〈0．01）;CAn含量及Gs活力分别为（0．155±0．04）μmol／g蛋白及（23．89±3．60）u儋蛋白,Na＋-K＋-ATPase及Ca2＋-ATPase活力分别为（4．03±0．57）μmol／（mg蛋白·h）及（2．21±0．62）μmol／（mgg蛋白·h）,均低于对照组（P〈0．01）;与甲基汞高剂量染毒组比较,α-LA干预组大鼠脑汞含量未见明显变化;Glu含量（63．02±3．33）μmol／g蛋白及PAG活力（26．03±3．88）μmol/（min·g蛋白）均降低（P〈0．01或P〈0．05）,Gin含量（0．20±0．05）μmol／g蛋白、GS活力（34．05士4．23）U／g蛋白、Na＋-K＋-ATPase活力为（5．52±1．16）μmol／（h·mg蛋白）及Ca2＋-ATPase活力为（3．27±0．60）μmol／（h·mg蛋白）,均升高（P〈0．01或P〈0．05）。[结论]a-LA对甲基汞所致大鼠脑谷氨酸代谢紊乱有一定的拮抗作用。     

血清同型半胱氨酸、叶酸、维生素B12浓度与多发性硬化的关系研究

目的：探讨血清同型半胱氨酸水平（Hcy）与多发性硬化（MS）的关系。方法：检测41例MS患者（MS组）和42例正常对照者（NC组）血清中Hcy浓度、叶酸及维生素B12浓度,并将结果进行比较分析。结果：MS组和NC组血清中Hcy浓度分别为（25.82±1.724）μmol/L、（13.60±1.517）μmol/L。MS组的Hcy浓度明显高于NC组,差异有统计学意义（P〈0.01）,而两组的叶酸、维生素B12浓度比较差异均无统计学意义（P〉0.05）。结论：MS患者血清Hcy水平升高,同型半胱氨酸可能在多发性硬化病理过程中起作用。     

1020名社区人群同型半胱氨酸水平的调查和相关分析

目的描述社区人群血浆同型半胱氨酸(Hcy)在不同年龄和性别间的分布特征,探讨Hcy与血脂水平等之间的相关性,研究高Hcy血症的危险因素及其对脑动脉狭窄的影响。方法从2500名社区人群筛选出1020名无心脑血管病史并可以进行经颅多普勒(TCD)检查的人群为样本,记录吸烟饮酒史、血压、人体测量学和生化资料,采用荧光生化法测定血浆Hcy水平,使用SPSS 12.0软件对检测指标进行处理。结果社区人群中Hcy水平男性(15．0μmol/L±5．8μmol／L)高于女性(12 4μmol／L±3．9μmol／L),差异有统计学意义(P<0．05);Hcy水平随着年龄增长而增高(P< 0．05);高Hcy血症的发生率男性(47．2％)高于女性(23．2％),差异有统计学意义(P<0．05);大脑中动脉狭窄组中Hcy水平(18．3μmol／L±5．3μmol/L)高于非狭窄组(12．9μmol／L±4．6μmol／L); logistic回归分析证实Hcy水平与血脂等之间无相关性,而仅与性别和年龄相关(P<0．05)。结论社区人群中Hcy水平存在性别和年龄的差异,两者是高Hcy血症的独立危险因素,Hcy水平与血脂等诸因素无相关性,高Hcy血症易致脑动脉狭窄。     

The plasma homocysteine, folic acid and vitamin B12 levels in young people with high risk for cardiovascular disease and its relation to metylentetrahydrofolate reductase (MTHFR) gene polymorphism

INTRODUCTION: Hyperhomocysteinemia is an independent risk factor for cardiovascular morbidity. AIM: The study was designed to evaluate the total homocysteine level and MTHFR C677T polymorphism frequency of 122, healthy, young adults who had increased risk for cardiovascular disease. The serum levels of folic acid and vitamin B12 were also measured. METHODS: Immunoassay, PCR-RFLP methods were used. The statistical analysis was performed by SPSS program. RESULTS: The frequency of the gene-polymorphism was not different significantly in the study group compared to a Hungarian neonatal sample: although in the increased risk group the frequency of homozygous 677TT polymorphism was higher (14.8%), and heterozygosity was smaller (41%). There was no association between MTHFR gene polymorphism and homocysteine levels. A significant negative correlation was found between the folic acid and homocysteine, and between the vitamin B12 and homocysteine levels correlating with the literature. The mean serum total homocysteine level of the group without vitamin supplementation (n: 86) was 9.8 +/- 3.3 micromol/l, while in the other group with vitamin uptake (n: 36) this level was 7.5 +/- 3.0 micromol/l. There was a significant difference between the homocysteine levels of men and women. CONCLUSION: The results of the study correlate with the literature. It would be useful to call the attention of the Hungarian population to the importance of vitamin supply.     

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.     

同型半胱氨酸、叶酸和维生素B12水平与不良妊娠结局的相关性分析

目的:探讨同型半胱氨酸、叶酸和维生素B12与不良妊娠结局的相关性。方法:选取2016年10月-2017年3月发生不良妊娠结局的孕妇70例为观察组,未发生不良妊娠事件的孕妇627例为对照组,健康未孕育龄期妇女60例为未孕组。对比3组血清同型半胱氨酸、叶酸和维生素B12血清水平;通过Pearson相关性分析检验同型半胱氨酸和叶酸、维生素B12的相关性;通过非条件logistic多元逐步回归分析统计发生不良妊娠事件的相关危险因素。结果:观察组的同型半胱氨酸水平(11.2±2.8μmol/L)高于另外两组,而叶酸水平(645.9±281.4nmol/L)、维生素B12水平(247.2±102.3pmol/L)均低于另外两组(均P0.05);Pearson相关性分析结果显示,血清同型半胱氨酸水平与叶酸、维生素B12水平呈负相关关系(r=-0.089,-0.108,均P0.05);非条件logistic多元逐步回归分析结果显示,同型半胱氨酸升高、维生素B12降低以及年龄增大是不良妊娠发生的相关危险因素(均P0.05)。结论:同型半胱氨酸升高、维生素B12降低以及年龄增大是不良妊娠发生的相关危险因素,临床应加强孕期保健,对年龄较大的孕妇应加强同型半胱氨酸及维生素B12的监测,预防不良妊娠的发生。     

叶酸对脑梗塞大鼠神经细胞凋亡及Notch1 mRNA表达的影响

目的研究叶酸(FA)对脑梗塞大鼠缺血侧脑组织内神经细胞凋亡及Notch1 mRNA表达的影响。方法雄性SD大鼠48只按体重随机分为4组:假手术组(SO)、大脑中动脉梗塞组(MCAO)、MCAO+叶酸低剂量组(MCAO+LFA)、MCAO+叶酸高剂量组(MCAO+HFA)。除SO组外,其他三组均采用线拴法制作大鼠大脑中动脉栓塞,各组于栓塞处理后第14天处死。补充叶酸前、补充28天后及栓塞处理后第14天,采用化学发光免疫法测定各组大鼠血清叶酸含量;建立MCAO后第14天,应用TUNEL法测定缺血侧脑组织内神经细胞的凋亡,荧光原位杂交法检测神经细胞内Notch1 mRNA的表达。结果补充叶酸后,与MCAO组相比,MCAO+LFA、MCAO+HFA组神经细胞凋亡率明显降低(P<0.01),血清叶酸浓度及Notch1 mRNA的荧光强度值均明显升高(P<0.01)。结论叶酸降低脑梗塞大鼠神经细胞凋亡率可能与其促进Notch1 mRNA的表达有关。     

Plasma total homocysteine,folate, and vitamin B12 status in Korean adults

Elevated plasma total homocysteine (tHcy) levels have been established as a risk factor for occlusive cardiovascular disease. Also known is that plasma folate and vitamin B12 influence homocysteine metabolism as cosubstrate and cofactor, respectively. However, not much information is available describing plasma tHcy levels and their relationship to plasma folate and vitamin B12 status in Koreans. We measured the plasma levels of tHcy, folate, and vitamin B12 in 195 adults (99 males, 96 females; 23-72 y old in the lower middle class). The mean plasma tHcy levels of males, 11.18 +/- 3.88 micromol/L, was significantly higher (p < 0.001) than that of females, 9.20 +/- 2.65 micromol/L. The distribution of tHcy levels of males showed a wide range, 3-50 micromol/L, with a long tail toward higher values. Thus the incidence of hyperhomocysteinemia (> or = 5 micromol/L) in males, 10.1%, was significantly higher (< 0.02) than the 2.1% in females. As age increased, plasma tHcy levels tended to be higher in females. Therefore, sex differences in plasma tHcy levels disappeared in subjects over fifty. On the other hand, both plasma folate (6.47 +/- 3.06 vs 7.96 +/- 3.55 ng/mL, p < 0.01) and vitamin B12 levels (537.0 +/- 222.0 vs. 664.1 +/- 309.8 ng/mL, p < 0.01) were significantly lower in males than in females. A plasma folate deficiency (< 3.0 ng/mL) was found in 6.1% of males and 2.1% of females. And a vitamin B12 deficiency (< 150 pg/mL) was detected in 2.0% and 1.0%, respectively. Plasma tHcy levels were related with inversely plasma concentrations of folate (r = -0.37249, p < 0.001) as well as vitamin B12 (r = -0.22560, p < 0.01) in both sexes. Plasma levels of tHcy and the prevalence of hyperhomocysteinemia in Korean adults are similar to findings in the West. Our results indicate that male adults may be in worse condition for cardiovascular disease (CVD) than females. And improving folate and vitamin B12 status may reduce plasma tHcy level, which may be more important in males.     

Homocysteine concentrations in adults with trisomy 21: effect of B vitamins and genetic polymorphisms

BACKGROUND: The effects of supplementation with B vitamins and of common polymorphisms in genes involved in homocysteine metabolism on plasma total homocysteine (tHcy) concentrations in trisomy 21 are unknown. OBJECTIVES: We aimed to determine the effects of orally administered folic acid and of folic acid combined with vitamin B-12, vitamin B-6, or both on tHcy in adults with trisomy 21. The study was also intended to analyze the possible influence of gene polymorphisms. DESIGN: One hundred sixty adults with trisomy 21 and 160 healthy, unrelated subjects aged 26 +/- 4 y were included. Plasma tHcy, red blood cell folate, serum folate, and vitamin B-12 were measured. Genotyping for the common methylenetetrahydrofolate reductase (MTHFR) 677C-->T, MTHFR 1298A-->C, cystathionine beta-synthase 844Ins68, methionine synthase 2756A-->C, methionine synthase reductase 66A-->G, and reduced folate carrier 80G-->A polymorphisms was carried out. RESULTS: The mean tHcy concentration (9.8 +/- 0.7 micromol/L) of cases who did not use vitamins was not significantly different from that of controls (9.4 +/- 0.3 micromol/L). Plasma tHcy concentrations (7.6 +/- 0.3 mmol/L) in cases who used folic acid were significantly lower than in cases who did not. Folic acid combined with vitamin B-12 did not significantly change tHcy concentrations compared with those in cases who used only folic acid. Folic acid combined with vitamins B-6 and B-12 significantly lowered tHcy (6.5 +/- 0.5 micromol/L). The difference in tHcy according to MTHFR genotype was not significant. However, tHcy concentrations were slightly higher in TT homozygotes among the controls but not among the cases. CONCLUSION: This study provides information on the relation between several polymorphisms in genes involved in homocysteine and folate metabolism in adults with trisomy 21.     

Breakfast cereal fortified with folic acid, vitamin B-6, and vitamin B-12 increases vitamin concentrations and reduces homocysteine concentrations: a randomized trial

BACKGROUND: High homocysteine and low B vitamin concentrations have been linked to the risk of vascular disease, stroke, and dementia and are relatively common in older adults. OBJECTIVE: We assessed the effect of breakfast cereal fortified with folic acid, vitamin B-6, and vitamin B-12 on vitamin and homocysteine status. DESIGN: A randomized, double-blind trial was conducted in 189 volunteers aged 50-85 y. The subjects had no history of hypertension, anemia, asthma, cancer, or cardiovascular or digestive disease and did not regularly consume multiple or B vitamin supplements or highly fortified breakfast cereal. Subjects were randomly assigned to consume 1 cup (0.24 L) breakfast cereal fortified with 440 microg folic acid, 1.8 mg vitamin B-6, and 4.8 microg vitamin B-12 or placebo cereal for 12 wk. Blood was drawn at 0, 2, 12, and 14 wk. Methionine-loading tests were conducted at baseline and week 14. RESULTS: Final baseline-adjusted plasma homocysteine concentrations were significantly lower and B vitamin concentrations were significantly higher in the treatment group than in the placebo group (P < 0.001). The percentage of subjects with plasma folate concentrations < 11 nmol/L decreased from 2% to 0%, with vitamin B-12 concentrations < 185 pmol/L from 9% to 3%, with vitamin B-6 concentrations < 20 nmol/L from 6% to 2%, and with homocysteine concentrations > 10.4 micromol/L (women) or > 11.4 micromol/L (men) from 6.4% to 1.6%. The percentage of control subjects with values beyond these cutoff points remained nearly constant or increased. CONCLUSIONS: In this relatively healthy group of volunteers, consumption of 1 cup fortified breakfast cereal daily significantly increased B vitamin and decreased homocysteine concentrations, including post-methionine-load homocysteine concentrations.     

Plasma vitamin B12, folate and homocysteine levels in gastrectomized men

BACKGROUND & AIMS: Hyperhomocysteinemia is a risk factor for cardiovascular disease, dementia and depression. Prevalence rate of hyperhomocysteinemia in gastrectomized patients is not well elucidated. METHODS: We compared plasma total homocysteine, vitamin B12 and folate of gastrectomized male patients with those of control subjects. RESULTS: Total homocysteine was higher in gastrectomized patients than in control subjects (11.7 +/- 4.4 micromol/l vs. 9.3 +/- 2.4 micromol/l, P = .011), while vitamin B12 was lower in patients than in control subjects (382 +/- 211 pg/ml vs. 500 +/- 179 pg/ml, P = .020). Folate of the two groups was comparable (5.8 +/- 2.5 ng/ml vs. 5.9 +/- 2.2 ng/ml). Of 31 gastrectomized patients six (19.4%) showed low vitamin B12 (<233 pg/ml), four (12.9%) low folate (<3.0 ng/ml) and seven (22.6%) hyperhomocysteinemia (>14 micromol/l), whereas they were found in one (3.2%), none (0%) and one (3.2%) of 31 control subjects, respectively. Patients who had undergone gastrectomy because of cancer showed higher total homocysteine compared to patients who had undergone it because of peptic ulcer. Type of surgery did not correlate with total homocysteine in the present study. CONCLUSION: Hyperhomocysteinemia is not rare in male Japanese gastrectomized patients.     

Effect of fortified spread on homocysteine concentration in apparently healthy volunteers

OBJECTIVE: To determine the effect of folic acid, vitamin B(6) and B(12) fortified spreads on the blood concentrations of these vitamins and homocysteine. DESIGN AND SETTING: A 6-week randomized, double-blinded, placebo-controlled, parallel trial carried out in a clinical research center. SUBJECTS: One hundred and fifty healthy volunteers (50% males). INTERVENTIONS: For 6 weeks, the subjects consumed the test spreads (20 g/day): containing per 20 g (1) 200 microg folic acid, 2 microg vitamin B(12) and 1 mg vitamin B(6), or (2) 400 microg folic acid, 2 microg vitamin B(12) and 1 mg vitamin B(6) or (3) no B-vitamins (control spread). RESULTS: The B-vitamin status increased on using the test spreads, with the largest effect on the serum folate concentration: 48% in men and 58% in women on spread 1 and 92 and 146%, respectively, on spread 2 (P-values all <0.05). The plasma homocysteine decreased in the groups treated with the fortified spreads as compared to the control group. Average decreases were for males: 0.7+/-1.5 micromol/l (6.8%) on spread 1 and 1.7+/-1.7 micromol/l (17.6%) on spread 2 and for females: 1.4+/-1.2 micromol/l (14.2%) and 2.4+/-2.0 micromol/l (23.3%), respectively (P-values all <0.05). CONCLUSIONS: Consumption of a spread fortified with folic acid, vitamin B(6) and vitamin B(12) for 6 weeks significantly increases the blood concentrations of these vitamins and significantly decreases the plasma concentration of homocysteine. Fortified staple foods like spreads can contribute to the lowering of homocysteine concentrations.