血清中氧化三甲胺的高效液相色谱串联质谱法测定研究

目的建立人血清中胆碱依赖肠道菌群代谢物——氧化三甲胺(TMAO)的高效液相色谱串联质谱法(HPLC-MS/MS)的测定方法,并研究其精密度和稳定性。方法以d9-TMAO为内标,血清经乙腈除蛋白后,采用Si O2柱(2.1 mm×100 mm,5μm)、乙腈-甲酸铵(10 mmol/L,p H 3.0)等度洗脱,选择多反应监测模式测定,测定方法的精密度和准确度及不同保存条件下的稳定性。结果本研究方法的检测限和定量限分别为0.003和0.063μmol/L,线性范围为0.16~20.00μmol/L(r2=0.999 9),不同浓度点的日内变异系数为2.03%~2.64%,日间变异系数为6.00%~9.94%,回收率为89.5%~103.0%;血清在4℃保存时,24 h内TMAO浓度变化在10%以内,72 h后TMAO浓度升高明显,浓度变化为15.85%;血清保存于-80℃时,72 h后TMAO浓度变化范围均在10%以内;反复冻融4个冻融循环内浓度变化仍在15%的可接受范围内。结论本研究建立的高效液相色谱串联质谱法检测TMAO的方法具有快速、准确且灵敏的特点,可以满足大样本人群血样检测要求。血液样本保存时应注意保存温度、时间对TMAO浓度的影响。     

高效液相色谱-串联质谱法测定牛奶中8种青霉素类药物

目的建立一种高效液相色谱-串联质谱(HPLC-MS/MS)法快速测定牛奶中8种青霉素类药物残留的检测方法。方法样品经氨化乙腈超声提取,旋蒸浓缩,正己烷脱脂,经C18色谱柱分离,以乙腈-5 mmol/L乙酸铵(含0.1%甲酸)溶液为流动相进行梯度洗脱,最后采用高效液相色谱-串联质谱法在正离子多反应监测模式下测定。结果 8种青霉素类药物在2μg/L~200μg/L时具有良好的线性关系,相关系数(r)为0.996 5~0.999 5,检出限和定量限分别为0.05μg/kg~2.70μg/kg和0.17μg/kg~8.90μg/kg;方法的回收率为87.8%~108.6%,相对标准偏差(RSD)为7.2%~10.8%。结论该法具有耗时短、试剂使用少、灵敏度高、特异性强等特点,已应用于实际样品的检测,并取得满意结果。     

固相萃取-液相色谱-串联质谱法测定水中的6种雌激素

目的建立水中6种雌激素的固相萃取-液相色谱-串联质谱检测方法。方法利用固相萃取前处理技术,液相色谱串联质谱的方法测定水中6种雌激素。液相色谱选择C_(18)色谱柱作为分离柱,甲醇、乙腈和水作为流动相梯度洗脱,串联质谱多反应监测模式进行检测。实验方法优化了质谱条件、液相色谱条件和固相萃取前处理条件。应用该方法测定了10份自来水样品。结果 6种雌激素在0 ng/L~5 000 ng/L时呈良好的线性关系,相关系数0.995,定性检出限为8.68 ng/L~103 ng/L,回收率为80.3%~93.0%,相对标准偏差(RSD)均≤15.5%。结论本方法不但可以同时测定水中6种雌激素,而且具有灵敏度好、选择性好、准确度高等优点。     

体检人群血清甜菜碱、胆碱水平及其影响因素分析

目的胆碱和甜菜碱是体内重要的甲基供体,探讨性别、年龄、体格测量指标、吸烟、饮酒等因素与血清甜菜碱、胆碱水平的关联性,为甜菜碱和胆碱在慢病防治中的应用提供流行病学依据。方法采用问卷调查的方法收集1643例(男1078,女565)体检人群的一般情况和生活行为方式资料,测量身高、体重、腰围、臀围并计算体质指数(body mass index,BMI)和腰臀比率,采用高效液相色谱-串联质谱法检测血清中甜菜碱、胆碱的水平。结果男性血清甜菜碱、胆碱水平分别比女性高16.9%和12.0%;65岁及以上人群血清甜菜碱和胆碱水平显著高于其他年龄组人群;与BMI、腰围、腰臀比率正常的人群相比,诊断为肥胖的人群血清甜菜碱水平均显著降低,但血清胆碱水平无统计学差异;不饮酒者血清甜菜碱水平高于饮酒者,但只与酒精摄入量≥21g/d的饮酒者间的差异有统计学意义,血清甜菜碱的水平在不同吸烟状态的人群中无统计学差异,血清胆碱水平在不同吸烟状态及不同酒精摄入量的人群中差异均无统计学意义。结论男性血清胆碱、甜菜碱水平高于女性,中老年人血清胆碱、甜菜碱水平较高,肥胖人群血清甜菜碱水平较低,过量饮酒可能会降低血清甜菜碱的水平。     

直接进样-超高效液相色谱-串联质谱法测定饮用水中莠去津及其4种代谢产物

目的建立直接进样-超高效液相色谱-串联质谱法测定生活饮用水中莠去津及其代谢产物的残留。方法水样经0.22μm滤膜过滤后直接进样,超高效液相色谱串联三重四级杆质谱分析;以ACQUITY UPLC BEH C18(2.1 mm×50 mm,1.7μm)色谱柱分离,乙腈-水溶液为流动相进行梯度洗脱,采用正离子扫描多反应监测(MRM)模式检测。结果莠去津及其代谢产物在各自的考察浓度范围内线性关系良好(r≥0.999 7)。方法的检出限为0.000 5μg/L~0.04μg/L,莠去津及其代谢产物在出厂水和水源水中的加标回收率分别为81.4%~104.3%、74.7%~103.7%,相对标准偏差(n=7)分别为2.3%~6.6%、3.0%~8.0%。结论该方法操作简单、快捷,灵敏度和准确度均较高,精密度较好,适用于生活饮用水中莠去津及其代谢产物残留的测定。     

高效液相色谱-串联质谱联用法测定果汁中的展青霉素、乐果和多菌灵

目的建立高效液相色谱-串联质谱法同时测定果汁中展青霉素、乐果和多菌灵的方法。方法果汁采用Qu ECh ERS前处理方法,以C18色谱柱为分离柱,以水-乙腈为流动相进行梯度洗脱,用高效液相色谱-串联质谱(HPLCMS/MS),电喷雾电离(ESI),多反应监测(MRM)模式检测,外标法同时定量测定展青霉素、乐果和多菌灵。结果方法的线性范围展青霉素为5~500μg/L、乐果为0.1~10μg/L、多菌灵为0.1~10μg/L,线性相关系数在0.9991~0.9999之间,展青霉素检出限为5.0μg/L、乐果检出限为0.01μg/L、多菌灵检出限为0.01μg/L;本方法平均加标回收率82.2%~90.0%之间;相对标准偏差(RSD)均小于5.3%。结论该方法可应用于同时定量检测果汁中展青霉素、乐果和多菌灵,操作简单、快速、准确可靠。     

液相色谱-串联质谱法快速检测全血和尿液中29种药物

目的 建立液相色谱-串联质谱法快速检测全血和尿液中29种药物的方法。
方法 全血样品用乙腈沉淀蛋白经Ostro 96孔磷脂去除板净化,尿液样品用乙腈直接提取,采用ODS反相色谱柱分离,高效液相色谱-串联质谱多反应监测模式检测,外标法定量。
结果 血样中29种药物在各自质量浓度范围内线性良好,相关系数为0.996 3~0.999 6,方法检出限为0.2~6.0 μg/L,样品加标回收率为92.0%~109.4%,相对标准偏差（RSD）为1.0%~12.8%。尿样中29种药物在各自质量浓度范围内线性良好,相关系数为0.997 9~0.999 9,方法检出限为0.1~6.9 μg/L,样品加标回收率为92.2%~111.8%,相对标准偏差（RSD）为1.0%~11.6%。
结论 该方法简便、快速、灵敏、准确,适用于中毒病人全血和尿液中29种药物的快速检测。
     

HPLC法测定血清肉碱的研究

目的:建立高效液相色谱(HPLC)测定血清中肉碱浓度的方法。方法:血清样品用乙腈、甲醇沉淀蛋白,加入肉碱衍生剂,60℃恒温水浴2h后进样10μl。色谱柱为AtlantisC18柱(4.6mm×150mm,5μm),流动相为甲醇∶异丙醇∶乙腈(35∶45∶20,v/v),流速1.0ml/min,紫外检测波长260nm。结果:在上述色谱条件下,血清肉碱分离良好,回归方程为Y=8490X-48200,r=0.9999,线性范围为12.5~400μmol/L。最低检测浓度为12.5μmol/L。日内精密度1.6%~13.2%,日间精密度(%)1.8%~12.1%,回收率98.5%。结论:通过加入肉碱衍生剂,建立了HPLC法测定血清中肉碱浓度的方法。此法操作简单,耗时少,有良好的准确度,适用于临床检测。     

高效液相色谱-电感耦合等离子体质谱法同时测定海产品中6种砷形态的研究

目的建立高效液相色谱-电感耦合等离子体质谱联用(HPLC-ICP-MS)测定海产品中亚砷酸根As(Ⅲ)、砷酸根As(Ⅴ)、一甲基砷(MMA)、二甲基砷(DMA)、砷甜菜碱(AsB)和砷胆碱(AsC)6种砷形态的分析方法,了解海产品中砷的形态与含量。方法海产品经0.15mol/L硝酸溶液热提取后,高效液相色谱以色谱柱Dionex Ion Pac AS7(4mm×250mm,5μm)为分离柱,用碳酸铵为流动相进行梯度洗脱分离,用电感耦合等离子体质谱进行定量检测。结果 6种砷形态均达到良好分离,在2.5~150μg/L范围内有良好的线性关系,回收率82.0%~113.0%,相对标准偏差(RSD)5%;海产品中的砷主要以有机砷形式存在,砷甜菜碱含量较高。结论建立的砷形态分析方法简便、准确可靠,符合海产品砷形态检测的要求。     

液相色谱-串联质谱法检测化妆品中的甲硝唑

目的:建立化妆品中甲硝唑的液相色谱-串联质谱检测方法.方法:采用乙腈提取化妆品中的甲硝唑,以Diamonsil C18色谱柱分离,液相色谱-电喷雾串联质谱法测定.结果:化妆品中甲硝唑检测的线性范围为1～1000 ng/ml,定量检测限为1 ng/ml.3个添加水平的平均回收率在96%～102%范围内,相对标准偏差在10%以下.结论:本法快速、灵敏、准确,可快速检测化妆品中添加的甲硝唑.     

Betaine can partially spare choline in chicks but only when added to diets containing a minimal level of choline

The ability of betaine to serve as a methyl donor in chicks was assessed in 3 bioassays using a choline-free purified diet that contained adequate methionine (Met). In assay 1, choline and betaine were each supplemented at 300 mg/kg in a 2 x 2 factorial arrangement of diets. Supplemental choline improved (P < 0.05) growth performance over the 9-d growth period, whereas betaine alone had no effect. In assay 2, graded supplements of choline produced a linear increase (P < 0.05) in growth performance criteria over a 9-d growth period. Additionally, hepatic betaine-homocysteine (Hcy) methyltransferase (BHMT) activity decreased linearly (P < 0.05), whereas plasma total Hcy remained unchanged. Addition of 260 or 600 mg/kg betaine to the choline-free basal diet did not affect growth performance or BHMT activity, but 600 mg/kg betaine reduced (P < 0.05) plasma total Hcy. Assay 3 was designed to quantify the ability of betaine to spare choline. Minimal supplemental choline requirements of 20.8 +/- 1.50 mg/d (722 mg/kg diet) and 10.5 +/- 1.03 mg/d (412 mg/kg diet) were estimated in the absence and presence of 1000 mg/kg supplemental betaine, respectively. Based on these estimates, 50% of the dietary choline requirement must be supplied as choline per se, but the remaining 50% can be replaced by betaine. Collectively, these data suggest betaine and Met have minimal choline-sparing activity in chicks fed purified diets devoid of preformed choline. However, addition of betaine to diets containing minimal choline allows a marked reduction in the total dietary choline requirement.     

Adequate Intake levels of choline are sufficient for preventing elevations in serum markers of liver dysfunction in Mexican American men but are not optimal for minimizing plasma total homocysteine increases after a methionine load

BACKGROUND: An adequate intake of 550 mg choline/d was established for the prevention of liver dysfunction in men, as assessed by measuring serum alanine aminotransferase concentrations. OBJECTIVE: This controlled feeding study investigated the influence of choline intakes ranging from 300 to 2200 mg/d on biomarkers of choline status. The effect of the methylenetetrahydrofolate reductase (MTHFR) C677T genotype on choline status was also examined. DESIGN: Mexican American men (n = 60) with different MTHFR C677T genotypes (29 677TT, 31 677CC) consumed a diet providing 300 mg choline/d plus supplemental choline intakes of 0, 250, 800, or 1900 mg/d for total choline intakes of 300, 550, 1100, or 2200 mg/d, respectively, for 12 wk; 400 mug/d as dietary folate equivalents and 173 mg betaine/d were consumed throughout the study. RESULTS: Choline intake affected the response of plasma free choline and betaine (time x choline, P < 0.001); the highest concentrations were observed in the 2200 mg/d group. Phosphatidylcholine (P = 0.026) and total cholesterol (P = 0.002) were also influenced by choline intake; diminished concentrations were observed in the 300 mg/d group. Phosphatidylcholine was modified by MTHFR genotype (P = 0.035; 677TT < 677CC). After a methionine load (100 mg/kg body wt), choline intakes of 1100 and 2200 mg/d attenuated (P = 0.016) the rise in plasma homocysteine, as did the MTHFR 677TT genotype (P < 0.001). Serum alanine aminotransferase was not influenced by the choline intakes administered in this study. CONCLUSIONS: These data suggest that 550 mg choline/d is sufficient for preventing elevations in serum markers of liver dysfunction in this population under the conditions of this study; higher intakes may be needed to optimize other endpoints.     

The association between betaine and choline intakes and the plasma concentrations of homocysteine in women

BACKGROUND: Elevated total homocysteine (tHcy), a risk factor for many chronic diseases, can be remethylated to methionine by folate. Alternatively, tHcy can be metabolized by other 1-carbon nutrients, ie, betaine and its precursor, choline. OBJECTIVE: We aimed to assess the association between the dietary intakes of betaine and choline and the concentration of tHcy. DESIGN: We conducted a cross-sectional analysis in 1477 women by using linear regression models to predict mean fasting tHcy by intakes of of betaine and choline. RESULTS: tHcy was 8% lower in the highest quintile of total betaine + choline intake than in the lowest quintile, even after control for folate intake (P for trend = 0.07). Neither choline nor betaine intake individually was significantly associated with tHcy. Choline from 2 choline-containing compounds, glycerophosphocholine and phosphocholine, was inversely associated with tHcy. These inverse associations were more pronounced in women with folate intake < 400 mug/d than in those with intakes >or=400 microg/d (P for interaction = 0.03 for phosphocholine) and in moderate alcohol drinkers (>or=15 g/d) than in nondrinkers or light drinkers (<15 g/d) (P for interaction = 0.02 for glycerophosphocholine and 0.04 for phosphocholine). The strongest dose response was seen in women with a low-methyl diet (high alcohol and low folate intake) (P for interaction = 0.002 for glycerophosphocholine and 0.001 for phosphocholine). CONCLUSIONS: Total choline + betaine intake was inversely associated with tHcy, as was choline from 2 water-soluble choline-containing compounds. Remethylation of tHcy may be more dependent on the betaine pathway when methyl sources are low as a result of either inadequate folate intake or heavier alcohol consumption.     

Choline supplementation and measures of choline and betaine status: a randomised, controlled trial in postmenopausal women

Choline is an essential nutrient and can also be obtained by de novo synthesis via an oestrogen responsive pathway. Choline can be oxidised to the methyl donor betaine, with short-term supplementation reported to lower plasma total homocysteine (tHcy); however, the effects of longer-term choline supplementation are less clear. We investigated the effect of choline supplementation on plasma concentrations of free choline, betaine and tHcy and B-vitamin status in postmenopausal women, a group more susceptible to low choline status. We also assessed whether supplementation altered plasma lipid profiles. In this randomised, double-blinded, placebo-controlled study, forty-two healthy postmenopausal women received 1?g choline per d (as choline bitartrate), or an identical placebo supplement with their habitual diet. Fasting blood samples were collected at baseline, week 6 and week 12. Administration of choline increased median choline and betaine concentrations in plasma, with significant effects evident after 6 weeks of supplementation (P?相似文献   

Plasma choline and betaine and their relation to plasma homocysteine in normal pregnancy

BACKGROUND: Plasma concentrations of total homocysteine (tHcy) decrease during pregnancy. This reduction has been investigated in relation to folate status, but no study has addressed the possible role of betaine and its precursor choline. OBJECTIVE: We investigated the courses of plasma choline and betaine during normal human pregnancy and their relations to plasma tHcy. DESIGN: Blood samples were obtained monthly; the initial samples were taken at gestational week (GW) 9, and the last samples were taken approximately 3 mo postpartum. The study population comprised 50 women of West African descent. Most of the subjects took folic acid irregularly. RESULTS: Plasma choline (geometric x; 95% reference interval) increased continuously during pregnancy, from 6.6 (4.5, 9.7) micromol/L at GW 9 to 10.8 (7.4, 15.6) micromol/L at GW 36. Plasma betaine decreased in the first half of pregnancy, from 16.3 (8.6, 30.8) micromol/L at GW 9 to 10.3 (6.6, 16.2) micromol/L at GW 20 and remained constant thereafter. We confirmed a reduction in plasma tHcy, and the lowest concentration was found in the second trimester. From GW 16 onward, an inverse relation between plasma tHcy and betaine was observed. Multiple regression analysis showed that plasma betaine was a strong predictor of plasma tHcy from GW 20 onward. CONCLUSIONS: The steady increase in choline throughout gestation may ensure choline availability for placental transfer with subsequent use by the growing fetus. Betaine becomes a strong predictor of tHcy during the course of pregnancy. Both of these findings emphasize the importance of choline and betaine status during normal human pregnancy.     

Dietary choline and betaine assessed by food-frequency questionnaire in relation to plasma total homocysteine concentration in the Framingham Offspring Study

BACKGROUND: Epidemiologic studies of choline and betaine intakes have been sparse because a food-composition database was not available until recently. The physiologic relevance of a variation in dietary choline and betaine in the general population and the validity of intake assessed by food-frequency questionnaire (FFQ) have not been evaluated. OBJECTIVE: This study was conducted to examine the physiologic relevance and validity of choline and betaine intakes measured by an FFQ. DESIGN: We examined the relations between choline and betaine intakes measured by FFQ and plasma total homocysteine (tHcy) concentrations in 1960 participants from the Framingham Offspring Study. RESULTS: Higher intakes of dietary choline and betaine were related to lower tHcy concentrations independent of other determinants, including folate and other B vitamins. For the lowest and highest quintiles of dietary choline plus betaine, the multivariate geometric means for tHcy were 10.9 and 9.9 mumol/L (P for trend < 0.0001). The inverse association was manifested primarily in participants with low folate intakes (P for interaction < 0.0001). Among participants with folate intakes < or =250 microg/d, the geometric mean tHcy concentrations in the lowest and highest quintiles of choline plus betaine intakes were 12.4 and 10.2 micromol/L (P for trend < 0.0001). Except for choline from phosphatidylcholine, individual forms of choline were inversely associated with tHcy concentrations. CONCLUSIONS: Our findings provide support for a physiologically important variation in choline and betaine intakes in the general population and for the validity of intake measured by FFQ.     

Choline Kinetics in Neonatal Liver,Brain and Lung—Lessons from a Rodent Model for Neonatal Care

Choline requirements are high in the rapidly growing fetus and preterm infant, mainly serving phosphatidylcholine (PC) synthesis for parenchymal growth and one-carbon metabolism via betaine. However, choline metabolism in critical organs during rapid growth is poorly understood. Therefore, we investigated the kinetics of D9-choline and its metabolites in the liver, plasma, brain and lung in 14 d old rats. Animals were intraperitoneally injected with 50 mg/kg D9-choline chloride and sacrificed after 1.5 h, 6 h and 24 h. Liver, plasma, lungs, cerebrum and cerebellum were analyzed for D9-choline metabolites, using tandem mass spectrometry. In target organs, D9-PC and D9-betaine comprised 15.1 ± 1.3% and 9.9 ± 1.2% of applied D9-choline at 1.5 h. D9-PC peaked at 1.5 h in all organs, and decreased from 1.5–6 h in the liver and lung, but not in the brain. Whereas D9-labeled PC precursors were virtually absent beyond 6 h, D9-PC increased in the brain and lung from 6 h to 24 h (9- and 2.5-fold, respectively) at the expense of the liver, suggesting PC uptake from the liver via plasma rather than local synthesis. Kinetics of D9-PC sub-groups suggested preferential hepatic secretion of linoleoyl-PC and acyl remodeling in target organs. D9-betaine showed rapid turnover and served low-level endogenous (D3-)choline synthesis. In conclusion, in neonatal rats, exogenous choline is rapidly metabolized to PC by all organs. The liver supplies the brain and lung directly with PC, followed by organotypic acyl remodeling. A major fraction of choline is converted to betaine, feeding the one-carbon pool and this must be taken into account when calculating choline requirements.     

Divergent associations of plasma choline and betaine with components of metabolic syndrome in middle age and elderly men and women

Choline is involved in the synthesis of phospholipids, including blood lipids, and is the immediate precursor of betaine, which serves as a methyl group donor in a reaction converting homocysteine to methionine. Several cardiovascular risk factors are associated with plasma homocysteine, whereas little is known about their relationship to choline and betaine. We examined the relation of plasma choline and betaine to smoking, physical activity, BMI, percent body fat, waist circumference, blood pressure, serum lipids, and glucose in a population-based study of 7074 men and women aged 47-49 and 71-74 y. Overall plasma concentrations (means +/- SD) were 9.9 +/- 2.3 micromol/L for choline and 39.5 +/- 12.5 micromol/L for betaine. Choline and betaine were lower in women than in men and in younger subjects compared with older (P < 0.0001). Multivariate analyses showed that choline was positively associated with serum triglycerides, glucose, BMI, percent body fat, waist circumference (P < 0.0001 for all), and physical activity (P < 0.05) and inversely related to HDL cholesterol (P < 0.05) and smoking (P < 0.0001). Betaine was inversely associated with serum non-HDL cholesterol, triglycerides, BMI, percent body fat, waist circumference, systolic and diastolic blood pressure (P < 0.0001 for all), and smoking (P < 0.05) and positively associated with HDL cholesterol (P < 0.01) and physical activity (P < 0.0001). Thus, an unfavorable cardiovascular risk factor profile was associated with high choline and low betaine concentrations. Choline and betaine were associated in opposite directions with key components of metabolic syndrome, suggesting a disruption of mitochondrial choline dehydrogenase pathway.     

Evidence of choline depletion and reduced betaine and dimethylglycine with increased homocysteine in plasma of children with cystic fibrosis

Cystic fibrosis (CF) is associated with many clinical complications including steatosis for which the relation to defective CF transmembrane conductance regulator protein is unclear. Choline deficiency results in hepatic steatosis. Choline is the precursor of betaine, which donates methyl groups for remethylation of homocysteine to methionine and dimethylglycine. Previously, we have shown phospholipid malabsorption and increased plasma homocysteine in children with CF. In these studies we used normal phase HPLC with tandem mass spectrometry to determine plasma choline, betaine, and dimethylglycine in children with CF (n = 34) and healthy control children without CF (n = 15). Plasma choline, betaine, and dimethylglycine were significantly lower in children with CF (means +/- SEM, 6.48 +/- 0.35, 23.8 +/- 1.49, 1.49 +/- 0.13 mumol/L, respectively) than in children without CF (8.98 +/- 0.46, 37.3 +/- 1.84, 3.01 +/- 0.17 mumol/L, respectively). Plasma choline (r = 0.373, P = 0.007) and betaine (r = 0.399, P = 0.005) were positively related to methionine, and choline was inversely related to homocysteine (r = -0.316, P = 0.03). Choline, betaine, and dimethylglycine were all significantly and positively related to the plasma S-adenosylmethionine:S-adenosylhomocysteine (SAM:SAH) ratio (r = 0.294, r = 0.377, r = 0.442, respectively; P < 0.05). The plasma choline:betaine and betaine:dimethylglycine ratios did not differ between the children with CF and the control children, suggesting no increase in betaine synthesis, or betaine-dependent remethylation of homocysteine. These studies suggest that choline depletion may contribute to increased homocysteine in children with CF. Choline depletion and altered thiol metabolism may contribute to the clinical complications associated with CF.     

Choline-related supplements improve abnormal plasma methionine-homocysteine metabolites and glutathione status in children with cystic fibrosis

BACKGROUND: Liver triacylglycerol accumulation and oxidative stress are common in cystic fibrosis (CF) and also occur in choline deficiency. Previously, we showed an association between elevated plasma homocysteine, reduced ratios of S-adenosylmethionine to S-adenosylhomocysteine (SAM:SAH) and of phosphatidylcholine to phosphatidylethanolamine, and phospholipid malabsorption in children with CF. OBJECTIVE: The objective was to address a possible relation between altered methionine-homocysteine metabolism and choline metabolism in children with CF. DESIGN: Children with CF were assigned without bias to supplementation with 2 g lecithin/d (n = 13), 2 g choline/d (n = 12), or 3 g betaine/d (n = 10) for 14 d. Plasma concentrations of methionine, adenosine, cysteine, cysteinyl-glycine, glutathione, glutathione disulfide (GSSG), and fatty acids; SAM:SAH; and red blood cell phospholipids were measured within each group of children with CF before and after supplementation. Plasma from healthy children without CF (n = 15) was analyzed to obtain reference data. RESULTS: Children with CF had higher plasma homocysteine, SAH, and adenosine and lower methionine, SAM:SAH, and glutathione:GSSG than did children without CF. Supplementation with lecithin, choline, or betaine resulted in a significant increase in plasma methionine, SAM, SAM:SAH, and glutathione:GSSG and a decrease in SAH (n = 35). Supplementation with choline or betaine was associated with a significant decrease in plasma SAH and an increase in SAM:SAH, methionine, and glutathione:GSSG. Supplementation with lecithin or choline also increased plasma methionine and SAM. CONCLUSION: We showed that dietary supplementation with choline-related compounds improves the low SAM:SAH and glutathione redox balance in children with CF.