The effects of exercise training and acute exercise duration on plasma folate and vitamin B12

BACKGROUND/OBJECTIVES

Energy production and the rebuilding and repair of muscle tissue by physical activity require folate and vitamin B₁₂ as a cofactor. Thus, this study investigated the effects of regular moderate exercise training and durations of acute aerobic exercise on plasma folate and vitamin B₁₂ concentrations in moderate exercise trained rats.

MATERIALS/METHODS

Fifty rats underwent non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The ET group performed moderate exercise on a treadmill for 30 min/day, 5 days/week. At the end of week 5, each group was subdivided into 4 groups: non-exercise and 3 exercise groups. The non-exercise group (E0) was sacrificed without exercising and the 3 exercise groups were sacrificed immediately after exercising on a treadmill for 0.5 h (E0.5), 1 h (E1), and 2 h (E2). Blood samples were collected and plasma folate and vitamin B₁₂ were analyzed.

RESULTS

After exercise training, plasma folate level was significantly lower and vitamin B₁₂ concentration was significantly higher in the ET group compared with the NT group (P < 0.05). No significant associations were observed between plasma folate and vitamin B₁₂ concentrations. In both the NT and ET groups, plasma folate and vitamin B₁₂ were not significantly changed by increasing duration of aerobic exercise. Plasma folate concentration of E0.5 was significantly lower in the ET group compared with that in the NT group. Significantly higher vitamin B₁₂ concentrations were observed in the E0 and E0.5 groups of the ET group compared to those of the NT group.

CONCLUSION

Regular moderate exercise training decreased plasma folate and increased plasma vitamin B₁₂ levels. However, no significant changes in plasma folate and vitamin B₁₂ concentrations were observed by increasing duration of acute aerobic exercise.     

Dietary source of vitamin B12 intake and vitamin B12 status in female elderly Koreans aged 85 and older living in rural area

Recently, we found and analyzed vitamin B₁₂ in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B₁₂ intake and its dietary sources and the vitamin B₁₂ status in the very old elderly Koreans. We measured serum vitamin B₁₂ level and estimated the amounts of vitamin B₁₂ intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin B₁₂ concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin B₁₂ intake of our subjects was 3.2 µg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 µg/day. On dietary source, 67.3% of dietary vitamin B₁₂ was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin B₁₂ concentration was 450.5 pg/mL, and low serum vitamin B₁₂ (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B₁₂ intake was significantly lower in subjects with low serum vitamin B₁₂ (0.79 µg/day) than those with normal serum vitamin B₁₂ (3.47 µg/day). There were no significant difference in vitamin B₁₂ intake and its dietary sources and serum vitamin B₁₂ level between the 85-99 yr-old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B₁₂ status in very old elderly Koreans.     

叶酸、维生素B_(12)对糖尿病肾病大鼠肾脏保护作用的研究

目的研究叶酸、维生素B12与糖尿病大鼠肾脏病变之间的关系并探讨糖尿病肾脏病变的发生机制。方法选用SD大鼠80只,随机分为正常组(10只)和造模组(70只)。用高脂高糖高能量饲料喂养造模大鼠,10周后进行小剂量腹腔注射链脲佐菌素以诱导糖尿病大鼠模型,并将之分为糖尿病空白组、叶酸干预组、维生素B12干预组以及叶酸联合维生素B12干预组,继续喂养8周。实验期间测定血糖、总胆固醇、甘油三酯及胰岛素等并做肾脏PAS染色。结果①高脂饲料喂养较长时间后,再空腹注射低剂量链脲佐菌素(STZ)能成功诱导稳定的糖尿病大鼠模型。糖尿病模型大鼠的甘油三酯、总胆固醇水平及随机血糖分别为(1.07±0.27)、(2.29±0.42)和(21.12±4.21)mmol/L均较正常组的(0.68±0.11)、(1.11±0.20)和(5.73±0.26)mmol/L高,差异均有统计学意义(P<0.05)。②叶酸、维生素B12以及叶酸联合维生素B12均能减少糖尿病大鼠的24小时尿微量蛋白的增幅,其中联合干预组减少24小时尿蛋白增幅的作用最明显;各干预组大鼠的肾病理PAS染色显示肾脏病变程度均轻于糖尿病空白组大鼠,并且谷胱甘肽过氧化物酶(GSH-Px)水平高于糖尿病空白组大鼠,而丙二醛(MDA)水平明显低于糖尿病空白组大鼠(P<0.05)。结论对成年SD大鼠进行较长时间的高脂高糖高能量饲料喂养后,注射小剂量STZ能够诱导出糖尿病SD大鼠模型,补充叶酸、维生素B12能起到延缓肾脏病变的作用,其保护机制可能与抗氧化应激机制有关。     

叶酸、维生素B6、B12对脑缺血大鼠学习记忆的影响

目的研究叶酸、维生素B6（VB6）和B12（VB12）对局灶性脑缺血大鼠血浆同型半胱氨酸（homocysteine,Hcy）水平和学习记忆能力的影响。方法sD大鼠按体重随机分为假手术组（Sham OP）、大脑中动脉闭塞模型组（MCAO）、大脑中动脉闭塞＋叶酸组（MCAO＋FA）和MCAO＋复合维生素（叶酸、VB6和VB12）组（MCAO＋CV）,补充前、后和缺血后分别检测大鼠血浆Hcy浓度,缺血后进行神经功能评分,测定学习记忆能力。结果大鼠脑缺血后血浆Hcy浓度MCAO＋FA组（6．92±1．04）μmol／L和MCAO＋CV组（5．49±1．00）μmol／L低于Sham OP组（9．33±1．11）μmol／L和MCAO组（10．90±2．03）μmol／L（P〈0．05）,且MCAO＋CV组低于MCAO＋FA组（P〈0．05）;神经功能缺失评分MCAO＋FA组（1．75±0．46）和MCAO＋CV组（1．38±0．52）以及Y型迷宫中受电击次数MCAO＋FA组（123．50±39．77）和MCAO＋CV组（86．25±21．39）低于MCAO组神经功能缺失评分（2．62±0．52）和电击次数（173．25±46．32）（P〈0．05）,而记忆正确次数MCAO＋CV组（3．75±0．42）高于MCAO组（2．12±0．45）（P〈0．05）。结论叶酸能降低脑缺血大鼠血浆Hcy浓度,增强脑缺血大鼠学习记忆能力,改善神经功能,且联合补充VB6和VB12优于单独补充叶酸。     

妊娠妇女血清总同型半胱氨酸、叶酸和维生素B_(12)水平分析

目的:研究分析妊娠妇女血清总同型半胱氨酸(tHcy)、叶酸(FA)、维生素B12(Vit B12)水平以及与其相关疾病的关系。方法:选择正常妊娠285例、妊娠期高血压疾病81例、其他不良妊娠37例、非孕育龄健康对照98例,分别以比色法测定血清tHcy水平;化学发光法测定FA、Vit B12水平。结果:正常妊娠妇女tHcy、FA、Vit B12水平显著低于正常对照,差异有统计学意义(P<0.05或P<0.01);妊娠期高血压疾病、不良妊娠tHcy水平显著增高且与正常对照相比,差异有统计学意义(P<0.05);而妊娠期高血压疾病FA、Vit B12水平与正常妊娠相比,差异无统计学意义(P>0.05);不良妊娠FA、Vit B12水平与正常妊娠相比差异有统计学意义(P<0.05)。结论:妊娠期高血压疾病、不良妊娠血清tHcy水平显著增高;低水平FA、Vit B12可能是不良妊娠的重要因素之一。     

Biological Variability and Impact of Oral Contraceptives on Vitamins B6, B12 and Folate Status in Women of Reproductive Age

Vitamins B₆, B₁₂ and folate play crucial metabolic roles especially during the reproductive years for women. There is limited reporting of within-subject variability of these vitamins. This study aimed to determine the within and between subject variability in serum vitamins B₆, B₁₂, folate and erythrocyte folate concentrations in young women; identify factors that contribute to variability; and determine dietary intakes and sources of these vitamins. Data were obtained from the control group of a trial aimed at investigating the effect of iron on the nutritional status of young women (age 25.2 ± 4.2 year; BMI 21.9 ± 2.2 kg/m²). The coefficients of variability within-subject (CV_I) and between-subject (CV_G) for serum vitamins B₆, B₁₂ and folate, and erythrocyte folate were calculated. Food frequency questionnaires provided dietary data. CV_I and CV_G were in the range 16.1%–25.7% and 31.7%–62.2%, respectively. Oral contraceptive pill (OCP) use was associated (P = 0.042) with lower serum vitamin B₁₂ concentrations. Initial values were 172 ± 16 pmol/L and 318 ± 51 pmol/L for OCP and non-OCP users, respectively; with differences maintained at four time points over 12 weeks. BMI, age, physical activity, alcohol intake and haematological variables did not affect serum or erythrocyte vitamin concentrations. Vitamin B₁₂ intakes were derived from traditional and unexpected sources including commercial energy drinks. Young women using OCP had significantly lower serum vitamin B₁₂ concentrations. This should be considered in clinical decision making and requires further investigation.     

Evaluation of vitamin B12 status in Egypt IV: Food consumption patterns among lactating mothers and their impact on the intake of the vitamin

The adequacy of vitamin B₁₂ intake was assessed among 62 lactating mothers in the 2–32 weeks of lactation by an interactive 24-h recall and an open-ended food frequency questionnaire. Double portions of the foods consumed were sampled and assayed microbiologically for its vitamin B₁₂ content. Based on the food item and its respective vitamin B₁₂ content, combined with the usual portion size in grams and the frequency of consumption, a rapid calculator of approximate dietary vitamin B₁₂ intake was developed. The estimated vitamin B₁₂ intake averaged 4.17±0.74?µg/d. Only 25.8% of the lactating mothers had adequate vitamin B₁₂ intake (>2.5?µg vitamin B₁₂ daily). Three quarter of the studied population were consuming vitamin B₁₂<2.5?µg/d. Out of those, 50% had estimated daily intake <2.0?µg/d. This percentage prevalence confirms the additional burden on the lactating mothers to satisfy the daily vitamin B₁₂ requirement for its breast-fed baby.     

Vitamin B12 and Folic Acid Imbalance Modifies NK Cytotoxicity,Lymphocytes B and Lymphoprolipheration in Aged Rats

Different vitamin B₁₂ and folic acid concentrations could exacerbate the immune response. The aim was to evaluate different dietary folic acid and vitamin B₁₂ levels on the immune response in aged rats. Male Sprague Dawley aged rats were assigned to three folic acid groups (deficient, control, supplemented) each in absence of vitamin B₁₂ for 30 days. Several parameters of innate and acquired immune responses were measured. Serum and hepatic folate levels increased according to folic acid dietary level, while vitamin B₁₂ levels decreased. There was a significant decrease in natural killer cell-mediated cytotoxicity in the spleen for the vitamin B₁₂ deficient diet and folic acid control diet groups. Significant changes in CD45 lymphocyte subsets were also observed according to dietary imbalance. Lymphoproliferative response to concanavalin A and phytohemagglutinin did not differ significantly between groups. The spleen response to lipopolysaccharide increased significantly, but was unmodified for the other organs. An imbalance between dietary vitamin B₁₂ and folic acid concentrations alters some immunological parameters in aged rats. Therefore, the ratio between folate and vitamin B₁₂ could be as important as their absolute dietary concentrations.     

Influences of Vitamin B12 Supplementation on Cognition and Homocysteine in Patients with Vitamin B12 Deficiency and Cognitive Impairment

Vitamin B₁₂ deficiency is associated with cognitive impairment, hyperhomocysteinemia, and hippocampal atrophy. However, the recovery of cognition with vitamin B₁₂ supplementation remains controversial. Of the 1716 patients who visited our outpatient clinic for dementia, 83 had vitamin B₁₂ deficiency. Among these, 39 patients (mean age, 80.1 ± 8.2 years) had undergone Mini-Mental State Examination (MMSE) and laboratory tests for vitamin B₁₂, homocysteine (Hcy), and folic acid levels. The hippocampal volume was estimated using the z-score of the MRI-voxel-based specific regional analysis system for Alzheimer’s disease. This is multi-center, open-label, single-arm study. All the 39 patients were administered vitamin B₁₂ and underwent reassessment to measure the retested for MMSE and Hcy after 21−133 days (median = 56 days, interquartile range (IQR) = 43–79 days). After vitamin B₁₂ supplementation, the mean MMSE score improved significantly from 20.5 ± 6.4 to 22.9 ± 5.5 (p < 0.001). Hcy level decreased significantly from 22.9 ± 16.9 nmol/mL to 11.5 ± 3.9 nmol/mL (p < 0.001). Significant correlation was detected between the extent of change in MMSE scores and baseline Hcy values. The degree of MMSE score was not correlated with hippocampal atrophy assessed by the z-score. While several other factors should be considered, vitamin B₁₂ supplementation resulted in improved cognitive function, at least in the short term, in patients with vitamin B₁₂ deficiency.     

Folic acid and vitamin B12 supplementation lowers plasma homocysteine but has no effect on serum bone turnover markers in elderly women: a randomized,double-blind,placebo-controlled trial

An elevated homocysteine level is a newly recognized risk factor for osteoporosis. Older individuals may have elevated homocysteine levels due to inadequate folate intake and/or lower absorption of vitamin B₁₂. The aim of this study was to determine whether there is an impact of folic acid and vitamin B₁₂ supplementation on homocysteine levels and, subsequently, on bone turnover markers in older women with mildly to moderately elevated homocysteine levels. It is hypothesized that supplementation with folic acid and vitamin B₁₂ will improve homocysteine levels and, in turn, positively modify bone turnover markers in this population. This randomized, double-blind, placebo-controlled trial included 31 women (65 to 93 years) with homocysteine levels greater than 10 μmol/L. Participants were randomly assigned to receive either a daily folic acid (800 μg) and vitamin B₁₂ (1000 μg) (n = 17) or a matching placebo (n = 14) for 4 months. The results showed significantly lower homocysteine concentrations in the vitamin group compared to the placebo group (10.6 vs 18.5 μmol/L, P = .007). No significant difference in serum alkaline phosphatase or C-terminal cross-linking telopeptide of type I collagen was found between the vitamin and placebo groups before or after supplementation. The use of folic acid and vitamin B₁₂ as a dietary supplement to improve homocysteine levels could be beneficial for older women, but additional research must be conducted in a larger population and for a longer period to determine if there is an impact of supplementation on bone turnover markers or other indicators of bone health.     

Vitamin B12 in health and disease

Vitamin B(12) is essential for DNA synthesis and for cellular energy production.This review aims to outline the metabolism of vitamin B(12), and to evaluate the causes and consequences of sub-clinical vitamin B(12) deficiency. Vitamin B(12) deficiency is common, mainly due to limited dietary intake of animal foods or malabsorption of the vitamin. Vegetarians are at risk of vitamin B(12) deficiency as are other groups with low intakes of animal foods or those with restrictive dietary patterns. Malabsorption of vitamin B(12) is most commonly seen in the elderly, secondary to gastric achlorhydria. The symptoms of sub-clinical deficiency are subtle and often not recognized. The long-term consequences of sub-clinical deficiency are not fully known but may include adverse effects on pregnancy outcomes, vascular, cognitive, bone and eye health.     

Effect of multivitamin supplementation on the homocysteine and methylmalonic acid blood concentrations in women over the age of 60 years

Summary Background Deficiency of folic acid, vitamin B₆ and/or vitamin B₁₂ can result in elevated total plasma homocysteine concentrations (tHcy), which are considered to be a risk factor for vascular disease. Studies have shown that supplementation of the three vitamins can lower tHcy even in subjects with tHcy in the normal range. Aim of the study The aim of this study was to evaluate the effect of a 6 month supplementation with vitamin B₆, B₁₂ and folate on the concentrations of total plasma homocysteine and serum methylmalonic acid (MMA) of elderly women. Methods The study was designed as a randomized placebo controlled doubleblind trial, and 220 healthy women (aged 60–91 years) were involved. The vitamin and mineral capsule contained pyridoxine (3.4 mg), folic acid (400 µg) and cobalamin (9 µg) in addition to other micronutrients. Blood concentrations of folate, cobalamin, tHcy, MMA and the activity coefficient of erythrocyte alpha-aspartic aminotransferase (alpha-EAST) were measured at baseline and after 6 months of supplementation. Dietary intake was evaluated at the beginning and the end of the intervention by two 3–day diet records. Results Median concentrations of serum cobalamin, serum folate and erythrocyte folate increased significantly and tHcy and alpha–EAST activity (indicative of improved status of vitamin B₆) coefficient decreased significantly in the supplemented group. Median MMA concentration of the supplemented group was significantly lower than that of the placebo group after the intervention. The vitamin supplementation had a greater decreasing effect on the tHcy concentration of volunteers with lower vitamin and higher tHcy initial concentrations. In a linear regression model, baseline tHcy, serum folate, age and alpha–EAST activity coefficient were significantly correlated with the change in tHcy. The change in MMA in the supplement group was significantly associated to the baseline MMA values. Conclusions Our results show that a 6 month supplementation including physiological dosages of B vitamins improves the status of these nutrients and reduces tHcy in presumed healthy elderly women.     

Maternal Vitamin B12 Deficiency Detected by Newborn Screening—Evaluation of Causes and Characteristics

Vitamin B₁₂ deficiency, mostly of maternal origin in newborns, is a well-treatable condition but can cause severe neurologic sequelae in infants. Early detection of vitamin B₁₂ deficiency allows the pre-symptomatic treatment of affected children. This evaluation assesses the characteristics of maternal vitamin B₁₂ deficiency detected by newborn screening. In a prospective single-center study, a systematic screening strategy for vitamin B₁₂ deficiency using a combination of two second-tier strategies was applied. In addition to confirmatory diagnostics in children, the systematic work-up of vitamin B₁₂ status was also performed for their mothers. Maternal characteristics were assessed including ethnic origin, diet, and vitamin supplementation during pregnancy. For affected mothers, a work-up by internal medicine was recommended. In total, 121 mother–infant couples were analyzed. 66% of mothers adhered to a balanced diet including meat. The cause of maternal vitamin B₁₂ deficiency was unknown in 56% of cases, followed by dietary causes in 32%, and organic causes in 8%. All mothers following a vegan diet and most mothers with a vegetarian diet took vitamin preparations during pregnancy, whereas only 55.8% of mothers with a balanced diet took folic acid or other vitamins. Maternal vitamin B₁₂, folic acid, and homocysteine levels were significantly correlated with the child’s folic acid levels, and with homocysteine, methylmalonic, and methylcitric acid levels in first and second NBS dried blood spots. Most children had normal blood counts and showed normocytosis. Although 36.7% of mothers showed anemia, only one presented with macrocytosis. Adherence to vitamin supplementation in pregnancy is low despite the recommendation for supplementation of folic acid. Ideally, the evaluation of mothers for vitamin B₁₂ levels and appropriate therapy should be initiated in early pregnancy. In infants detected through newborn screening, the multidisciplinary assessment and therapy of both children and mothers should be performed.     

叶酸、维生素B12和B6联合使用对心脑血管病发生风险影响随机对照试验的Meta分析

目的 评价联合补充叶酸、维生素B12和B6对心脑血管疾病发生风险的影响。方法 检索1980-2014年有关补充叶酸、维生素B12和B6与心脑血管疾病发生关系的随机对照试验文献,筛选符合条件的研究。研究指标包括心脑血管疾病事件、心肌梗死及中风,效应指标为反映发生风险的相对危险度（RR）及其95%CI。运用Meta分析方法进行效应综合,并做亚组分析和敏感性分析。采用Jadad评分对文献质量进行评价。结果 共纳入11项随机对照试验研究,包含26 395名研究对象。有8项研究综合显示3种B族维生素联合使用对心脑血管疾病事件的发生无显著影响（RR=1.00,95%CI：0.94～1.07）;9项研究综合显示3种B族维生素联合使用对心肌梗死的发生无显著影响（RR=1.03,95%CI：0.94～1.13）。9项研究综合显示3种B族维生素联合使用可使中风的发生风险降低14%（RR=0.86,95%CI：0.78～0.95）。维生素B合剂组与对照组同型半胱氨酸水平比较,联合服用叶酸、维生素B12和B6能使同型半胱氨酸水平降低2.53 μmol/L（95%CI：-3.93～-1.12）;亚组分析显示,随访时间、维生素剂量、疾病史均对心脑血管疾病事件的研究结论无显著影响;而中风的亚组分析显示,随着随访时间延长,补充B族维生素能降低中风的发生风险,叶酸和维生素B12在小剂量下预防中风的作用更为显著,而维生素B6随着剂量的增加效果显著,有心脑血管病史者联合补充B族维生素降低中风风险的效果较好。结论 联合补充叶酸、维生素B12和B6对心脑血管疾病事件、心肌梗死的发生无显著影响,但可以降低中风发生的风险和同型半胱氨酸的水平。     

肝病患者血清叶酸与维生素B12含量的临床意义

目的 探讨肝病患者血清叶酸(FA)与维生素B12(VitB12)含量的变化及其临床意义.方法 应用微粒子化学发光免疫分析技术(CLIA)检测315例肝病患者及84例健康对照者的血清FA和VitB12含量,并对检测数据进行统计学分析.结果 急性肝炎组血清FA含量与对照组比较,差异无统计学意义(P>0.05),但其VitB12含量明显高于对照组(P<0.05).慢性肝炎轻度组血清FA、VitB12含量与对照组相比,差异无统计学意义(P>0.05).慢性肝炎中度组血清FA、VitB12含量与对照组相比,差异有统计学意义(P<0.05).慢性肝炎重度组、肝炎后肝硬化组、原发性肝癌组的FA含量均低于对照组(P<0.01),VitB12含量均高于对照组(P<0.01).结论 血清FA、VitB12含量变化与肝细胞病损程度密切相关,其检测结果对肝脏疾病的诊断、治疗及预后判断具有重要的临床价值.     

Vitamin B12 Metabolism during Pregnancy and in Embryonic Mouse Models

Vitamin B₁₂ (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.     

叶酸与维生素B12对2型糖尿病大鼠心肌组织凋亡 相关蛋白表达的影响

摘要:目的　观察2型糖尿病大鼠心肌凋亡相关蛋白Bax、Bcl-2和Caspase-3的表达变化及叶酸、维生素B12的干预作用。方法　6周龄SD大鼠60只,糖尿病造模成功后,随机分为对照组（A组）、模型组（B组）、叶酸和维生素B12干预组（C组）。12周后取血检测各组同型半胱氨酸（Hcy）、叶酸、维生素B12的水平;取大鼠心肌组织,免疫组化法检测Bax,Bcl-2,Caspase-3的表达,并用计算机图像分析系统测平均灰密度值。结果　12周后B组Hcy明显增高,与A组和C组比较,差异均有统计学意义（P＜0.01）,C组叶酸、维生素B12与A组和B组比较,差异均有统计学意义（P＜0.01）;心肌组织中,B组Bax、Caspase-3的表达明显高于A组（P＜0.01）,Bcl-2的表达明显低于A组（P＜0.01）;C组Bax、Caspase-3的表达较B组明显下降（P＜0.01）,Bcl-2的表达明显高于B组（P＜0.01）;A组与C组Bax、Caspase-3、Bcl-2的表达差异无统计学意义（P＞0.05）。结论　2型糖尿病大鼠血液中Hcy的升高,可能在促进心肌细胞凋亡过程中发挥重要作用,而叶酸、维生素B12的干预可以有效缓解病变进程。     

Prevalence and Risk Factors of Vitamin B12 Deficiency among Pregnant Women in Rural Bangladesh

Vitamin B₁₂ deficiency is associated with an increased risk of pregnancy complications and adverse birth outcomes. However, data on vitamin B₁₂ deficiency in pregnant Bangladeshi women are limited. This study examines vitamin B₁₂ deficiency and marginal deficiency in rural Bangladeshi women during early and late pregnancies. Some 522 women whose gestational age was <20 weeks were recruited. Serum vitamin B₁₂ concentrations were measured at baseline and after 14 weeks of iron-folate supplementation. Logistic regression analysis examined the association of various socio-demographic, dietary, and pregnancy-related factors with vitamin B₁₂ deficiency and marginal deficiency. Overall, 19% of the women during early pregnancy had vitamin B₁₂ deficiency (serum vitamin B₁₂ concentration < 203 pg/mL) and nearly 40% had marginal deficiency (serum vitamin B₁₂ concentration 203 to <300 pg/mL). Vitamin B₁₂ deficiency doubled to 38% during late pregnancy, while marginal deficiency slightly increased to 41.7%. The pregnant women with a gestational age of ≥27 weeks had a higher risk of developing vitamin B₁₂ deficiency (OR = 2.61; 95% CI = 1.096–6.214) than those of a gestational age of <27 weeks. Vitamin B₁₂ deficiency was significantly higher in pregnant women in rented accommodation (OR = 13.32; 95% CI = 1.55–114.25) than in those living in their own house. Vitamin B₁₂ deficiency was significantly higher among women who consumed red or organ meat <3 times a week than in those who consumed it more often (OR = 2.327, 95% CI = 1.194–4.536). None of these factors were significantly associated with marginal vitamin B₁₂ deficiency. In conclusion, vitamin B₁₂ deficiency and marginal deficiency among pregnant rural Bangladeshi women increased as their pregnancies progressed. Increasing gestational age, living in a rented house, and the consumption of red or organ meat <3 times a week were identified as the independent risk factors of vitamin B₁₂ deficiency in this population. Further research with more in-depth assessments of dietary vitamin B₁₂ intakes is needed to develop an intervention program preventing vitamin B₁₂ deficiency in this population.     

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。     

Vitamin B12-Containing Plant Food Sources for Vegetarians

The usual dietary sources of Vitamin B₁₂ are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B₁₂. To prevent Vitamin B₁₂ deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B₁₂. A survey of naturally occurring plant-derived food sources with high Vitamin B₁₂ contents suggested that dried purple laver (nori) is the most suitable Vitamin B₁₂ source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.