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PubMed1984

Effect of phenobarbitone on folic acid metabolism in the rat.

Anticonvulsant drugs have well-known relationships with folic acid, often leading, in epileptic patients on long term treatment to signs of folic acid deficiency and to haematological complications. The findings of this work, carried out on rats, show strong interference of phenobarbitone with folic acid metabolism, particularly with pteroylpolyglutamate synthesis in liver. This is proved by lower polyglutamate content, lower 3H folate incorporation in polyglutamate forms and in protein-bound folates, and also by lower blood radioactivity, higher urinary excretion of 3H folate metabolites and by higher 3H folate concentration in kidneys.

Animals↗
PubMed2002

Diverse chemotactic responses of Dictyostelium discoideum amoebae in the developing (temporal) and stationary (spatial) concentration gradients of folic acid, cAMP, Ca(2+) and Mg(2+).

The responses of Dictyostelium discoideum amoebae to developing (temporal) and stationary (spatial) gradients of folic acid, cAMP, Ca(2+), and Mg(2+) were studied using the methods of computer-aided image analysis. The results presented demonstrate that the new type of experimental chambers used for the observation of single cells moving within the investigated gradients of chemoattractants permit time lapse recording of single amoebae and determination of the trajectories of moving cells. It was found that, besides folic acid and cAMP (natural chemoattractants for Dictyostelium discoideum amoebae), also extracellular Ca(2+) and Mg(2+) are potent inducers of these cells' chemotaxis, and the amoebae of D. discoideum can respond to various chemoattractants differently. In the positively developing gradients of folic acid, cAMP, Ca(2+), and Mg(2+) oriented locomotion of amoebae directed towards the higher concentration of the tested chemoattractants was observed. However, in the negatively developing (temporal) and stationary linear (spatial) gradients, the univocal chemotaxis of amoebae was recorded only in the case of the Mg(2+) concentration gradient. This demonstrates that amoebae can respond to both developing and stationary gradients, depending upon the nature of the chemoattractant. We also investigated the effects of chosen inhibitors of signalling pathways upon chemotaxis of D. discoideum amoebae in the positively developing (temporal) gradients of tested chemoattractants. Verapamil was found to abolish the chemotaxis of amoebae only in the Ca(2+) gradients. Pertussis toxin suppressed the chemotactic response of cells in the gradients of folic acid and cAMP but did not prevent chemotaxis in those of Ca(2+) and Mg(2+), while quinacrine inhibited chemotaxis in the gradients of folic acid, cAMP, and Ca(2+) but only slightly affected chemotaxis in the Mg(2+) gradient. None of the tested inhibitors causes inhibition of cell random movement, when applied in isotropic solution. Also EDTA and EGTA up to 50 mM concentration did not inhibit locomotion of amoebae in control isotropic solutions.

Amoeba↗
PubMed2003

Folic acid supplements and fortification affect the risk for neural tube defects, vascular disease and cancer: evolving science.

Folic acid supplements reduce the risk of neural tube defects and may be associated with reduced risk for vascular disease and cancer. Research data from both observational and controlled intervention studies provide strong support for the existing public health policies related to folic acid and neural tube defects. However, educational efforts to promote daily intake of folic acid supplements by women of reproductive age have not, in most cases, resulted in increased supplement use. In contrast, food fortification appears to be associated with a reduction in neural tube defects in the United States and Canada but is not practiced universally. The potential for folic acid supplements to reduce the incidence and severity of vascular disease and cancer is the focus of major research efforts including ongoing intervention studies.

Dietary Supplements↗
PubMed2004

Trends in twinning rates in metropolitan Atlanta before and after folic acid fortification.

OBJECTIVE: To examine whether trends in rates of twinning in metropolitan Atlanta increased after folic acid fortification. STUDY DESIGN: Live births to residents of 5 metropolitan Atlanta counties during the period 1990-2001 were identified from the state of Georgia's vital records. Rates of twinning and rate ratios were computed for the periods before and after fortification with folic acid. RESULTS: Of the 510,000 singleton and twin births in metropolitan Atlanta during the study period, 7168 (1.43%) represented twin pregnancies. Overall, the rate of twinning increased 18% (P < .001)from the prefortification to postfortification period. As compared with the rate of twinning during the prefortification period, that during the postfortification period increased by 23% (OR 1.23, 95% CI 1.7, 1.28) among women over 30 years but showed no increase among women <30 years of age (OR 1.02, CI 0.94, 1.10). Among women >30, there was an increasing rate of twinning throughout the prefortification period (4.9%). There was no upward trend in twinning rates among women younger than 30 years prior to fortification. CONCLUSION: Increasing trends of twinning were observed only in women older than 30 years, but these trends began prior to folic acid fortification and reached a plateau in recent years. Further elucidation of the possible relationship between folic acid and twinning will need to account for the use of fertility treatments by older women.

Age Factors↗
PubMed2005

[Effect of low doses of folic acid on selected biochemical atherosclerosis risk factors--preliminary study].

UNLABELLED: The aim of the present paper was evaluation of the impact of the three-months' supplementation with low doses of folic acid on concentration of homocysteine and other biochemical atherosclerosis risk factors with patients endangered with ischemic stroke or other disease being atherosclerosis-derivative. MATERIAL AND METHODS: The examined group consisted of 34 adult children of parents of which at least one fell ill at a young age with ischemic stroke. There were examined 9 men and 25 women aged from 19 to 36 years (average age 24.8 years). The testing procedure consisted in three-months' supplementation with folic acid (a 0.4 mg a day) and in check-up of blood parameters. The tests were performed prior to and after 3 months of taking folic acid. There were following laboratory tests performed: lipid profile [triglycerides, total cholesterol as well as LDL-cholesterol and HDL-cholesterol fractions, apolipoprotein B and Al, lipoprotein(a)] and folic acid, homocysteine, fibrinogen, von Willebrand factor as well as blood cell count, thrombocytes, ESR and basic biochemical parameters. RESULTS: Increased average concentration levels were detected for folic acid by 5.4 ng/dl (increase by 62.8%), apolipoprotein Al by 2.3 mg/dl (1.5%) and for fibrinogen by 0.2 g/l (7.1%). Decreased average concentration levels were detected for: homocysteine by 2.1 micromol/ l (drop by 18.9%) and for LDL-cholesterol by 4.4 mg/dl (4.4%/1). Furthermore, a significant increase in average concentration level of uric acid was detected as well as drop in average hemoglobin value, erythrocytes, creatinine and urea. Other blood cell count elements, thrombocytes, ESR and biochemical parameters did not show, in a check test, any significant differences. CONCLUSIONS: Low doses of folic acid, owing to its reducing influence on some risk factors, may be recommended with precautions in the atherosclerosis prevention, e.g. for families with past premature cardiovascular episode. However, insufficient number of tested persons does not permit to draw more radical conclusions. The tests should be conducted on a bigger group of patients.

Adult↗
PubMed1993

Effect of long-term addition of folic acid on folate status, growth performance, puberty attainment, and reproductive capacity of gilts.

Three groups of 34 gilts received, from 9 wk of age until slaughter at 7 wk of gestation, diets supplemented with either 0, 5, or 15 mg/kg of folic acid. The concentration of serum folates increased linearly (P < or = .05) with the level of added folic acid. Although the growth performance was not influenced by the treatments during the overall growing period, feed intake (P < or = .10) and body weight gain (P < or = .05) from 17 to 21 wk of age increased linearly as folic acid level in the diet increased. Age and body weight at puberty as well as body weight gain during gestation were not influenced (P > or = .32) by treatments. Dietary folic acid addition did not affect (P > or = .21) either total weight and empty weight of uterine horns or ovarian total weight, stroma weight, and number and weights of corpora lutea. No treatment effect (P > or = .35) was observed on placental surface, number of placental areolae, litter size, fetus weight, or total litter weight or on fetal DNA, RNA, and protein. However, the concentration of folates in fetuses increased linearly (P < or = .03) with the addition of folic acid in the dam's diet. In conclusion, although a dietary addition of as high as 15 mg/kg of folic acid seemed to influence growth performance of gilts by the end of the growing period, it did not affect age at puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1978

Predictive values of erythrocyte indices for tests of iron, folic acid, and vitamin B12 deficiency.

The probabilities of low transferrin saturation, folic acid, or vitamin B12 levels in association with various erythrocyte indices was determined from the prevalences of these abnormalities and the distributions of the indices among 206 hospitalized and 1,000 ambulatory anemic patients. At mean corpuscular hemoglobin (MCH) greater than 30 pg, the probability of low transferrin saturation was 0.04 for hospitalized patients and 0.14 for ambulatory anemic patients. For MCH less than 27 pg, the corresponding probabilities were 0.52 and 0.67. The probabilities of low vitamin B12 or folic acid levels among hospitalized anemic patients were 0.0011 for mean corpuscular volume (MCV) less than 95 cu micron and 0.18 for MCV greater than or equal to 95 cu micron, indicating that measurements of these vitamins are of very limited value in most cases of anemia. These findings indicate that in some patients, the erythrocyte indices are sufficiently predictive for or against deficiency states to facilitate decisions regarding further diagnostic tests, as opposed to the increasing tendency to order such tests regardless of the indices.

Anemia, Hypochromic↗
PubMed2004

Using CD-ROM technology to increase folic acid knowledge among physician assistant students.

The purpose of this study was to examine the effectiveness of incorporating CD-ROM technology to increase the knowledge of folic acid among physician assistant students. Participants included 76 first-year physician assistant students enrolled in a Women's Health course. A pretest and posttest was used to evaluate the knowledge gain after viewing the CD-ROM over a 2-week period. Of the 76 students in the course, 73 completed the pretest and the post-test. Posttest scores were significantly better than pretest scores (t = -11.83; p < or = 0.001), with means 68.63% and 46.18%. Knowledge scores increased by 22.45% from pre-test to posttest. Student evaluation results suggested that the CD-ROM (1) provided folic acid information in a clear and effective manner, (2) adequately covered the folic acid information, (3) increased student awareness and knowledge about folic acid, and (4) may promote early commitment by students to recommend daily folic acid intake to their patients.

Allied Health Occupations↗
PubMed2005

International retrospective cohort study of neural tube defects in relation to folic acid recommendations: are the recommendations working?

OBJECTIVES: To evaluate the effectiveness of policies and recommendations on folic acid aimed at reducing the occurrence of neural tube defects. DESIGN: Retrospective cohort study of births monitored by birth defect registries. SETTING: 13 birth defects registries monitoring rates of neural tube defects from 1988 to 1998 in Norway, Finland, Northern Netherlands, England and Wales, Ireland, France (Paris, Strasbourg, and Central East), Hungary, Italy (Emilia Romagna and Campania), Portugal, and Israel. Cases of neural tube defects were ascertained among liveborn infants, stillbirths, and pregnancy terminations (where legal). Policies and recommendations were ascertained by interview and literature review. MAIN OUTCOME MEASURES: Incidences and trends in rates of neural tube defects before and after 1992 (the year of the first recommendations) and before and after the year of local recommendations (when applicable). RESULTS: The issuing of recommendations on folic acid was followed by no detectable improvement in the trends of incidence of neural tube defects. CONCLUSIONS: Recommendations alone did not seem to influence trends in neural tube defects up to six years after the confirmation of the effectiveness of folic acid in clinical trials. New cases of neural tube defects preventable by folic acid continue to accumulate. A reasonable strategy would be to quickly integrate food fortification with fuller implementation of recommendations on supplements.

Abortion, Induced↗
PubMed2005

Alginate-pectin microcapsules as a potential for folic acid delivery in foods.

Most naturally occurring folate derivatives in foods are highly sensitive to temperature, oxygen, light and their stability is affected by processing conditions. Folic acid incorporated microcapsules using alginate and combinations of alginate and pectin polymers were prepared to improve stability. Folic acid stability was evaluated with reference to encapsulation efficiency, gelling and hardening of capsules, capsular retention during drying and storage. Use of alginate in combination with pectin produced more robust capsules and contributed to greater encapsulation efficiency. The capsules lost their spherical shape as a consequence of increased pectin. The high alginate capsules, A100:P0 (100% alginate: 0% pectin) and A80:P20 (80% alginate: 20% pectin) were of regular spherical shape, while those with more pectin, A70:P30 (70% alginate: 30% pectin) and A60:P40 (60% alginate: 40% pectin) formed irregular spheres. The loading efficiency, expressed as a percentage of the actual loading to theoretical loading, varied from 55-89% with the composition of the mixed polymers. After 11 weeks of storage at 4 degrees C, folic acid retention in freeze-dried capsules was 100% (A70:P30 and A60:P40), 80% (A80:P20) and 30% (A100:P0). The blended alginate and pectin polymer matrix increased folic acid encapsulation efficiency and reduced the leakage from the capsules compared to those made with alginate alone and showed higher folic acid retention after freeze drying and storage.

Alginates↗
PubMed2004

Short-term effect of folic acid supplementation in renal transplant recipients and chronic kidney disease patients with comparable renal function impairment.

Recent evidence suggested that the efficacy of folic acid supplementation in reducing plasma total homocysteine (Hcy) concentration might be similar in renal transplant recipients (RTR) and chronic kidney disease (CKD) patients with a comparable degree of reduction of renal function. However, a direct comparison of the response to high dose folic acid supplementation between renal transplant recipients and CKD patients has never been made. Therefore, the goal of this study was to evaluate the response to folic acid (5 mg/day) supplementation in 15 stable renal transplant recipients with evidence of chronic allograft nephropathy, and in 15 CKD (stage 3) patients matched for age, sex and renal function living in the area of Skopje, Macedonia. After 12 weeks of folic acid supplementation, plasma total Hcy concentrations were significantly reduced in the two groups. Percent reduction of plasma total Hcy levels was nearly identical in the two groups (25.7% vs 24.5%, p = NS). These results confirm previous findings regarding the efficacy of folic acid therapy given separately to either renal transplant recipients or CKD patients, and extend them to a direct confirmation of identical efficacy.

Adult↗
PubMed2004

Homocysteine is lower in the third trimester of pregnancy in women with enhanced folate status from continued folic acid supplementation.

BACKGROUND: In many countries, current recommendations are that women take a daily 400-mug folic acid supplement from before conception until the end of the 12th week of gestation for the prevention of neural tube defects. Low folate status is associated with an increased concentration of plasma total homocysteine (tHcy), a risk factor associated with pregnancy complications such as preeclampsia. METHODS: In a longitudinal study, we determined tHcy and corresponding folate status in 101 pregnant women at 12, 20, and 35 weeks of gestation, in 35 nonpregnant controls sampled concurrently, and in a subgroup (n = 21 pregnant women and 19 nonpregnant controls) at 3 days postpartum. RESULTS: Plasma tHcy was significantly lower throughout pregnancy compared with nonpregnant controls, with values lowest in the second trimester before increasing toward nonpregnant values in the third trimester. Importantly, mean tHcy concentrations were lower in pregnant women taking folic acid supplements than in those not, an effect that reached significance in the third trimester (5.45 vs 7.40 micromol/L; P <0.05). During the third trimester, tHcy concentrations were significantly higher in pregnant women with a history of miscarriage than in women with no previous history (8.15 vs 6.38 micromol/L; P <0.01). CONCLUSIONS: This is the first longitudinal study to show that homocysteine concentrations increase in late pregnancy toward nonpregnant values; an increase that can be limited by enhancing folate status through continued folic acid supplementation. These results indicate a potential role for continued folic acid supplementation in reducing pregnancy complications associated with hyperhomocysteinemia.

Adolescent↗
PubMed2001

[Prevention of congenital malformations by means of folic acid - insurmountable problems due to the German penal code and German drug legislation when preparing a preconceptional model in Saxony-Anhalt].

For the last 20 years the prophylactic effect of the vitamin folic acid against the occurrence of neural tube defects has been known but in Germany this fact has not been realized by the public. The recommendations by medical institutions fail, among other reasons, because a folic acid prescription by gynaecologists comes too late in the course of events, i.e., women go to the gynaecologist when pregnancy has already set in and it is too late for preventive measures. An effective folic acid prophylaxis must take place before the onset of pregnancy. Data from the regional surveillance of congenital anomalies of the German Federal State of Saxony-Anhalt and interviews with women in maternity, as well as gynaecologists, indicate that there is a substantial knowledge deficit concerning folic acid prophylaxis. In 1998, therefore, a working group was set up in Saxony-Anhalt. It comprises representatives from interested institutions and has the goal of rectifying the knowledge deficit of women of childbearing age by way of a broad-based campaign while making use of the results of regional congenital anomalies monitoring. A pharmaceutical company was enlisted for cost-free distribution of its folic acid product. Legal problems with the prescription drug laws, the law against unfair competitive practices, the advertising of medicaments law and the SGB V (social code) made it impossible to procure multivitamins containing folic acid free of charge for women wanting a child. A highly differentiated legislation has hitherto prevented an elementary improvement in prevention.

Drug Approval↗
PubMed2006

G1793A polymorphisms in the methylene-tetrahydrofolate gene: effect of folic acid on homocysteine levels.

Mutations or polymorphisms in the gene of the enzyme methylenetetrahydrofolate (MTHFR) are associated with hyperhomocysteinemia and possibly with an elevated risk for vascular diseases. A study was conducted on 83 individuals with type 2 diabetes in order to determine the allelic and genotypic frequencies of the G1793A mutation and to assess the effect of folic acid supplementation on plasma homocysteine concentrations. The patients were attended by the Diabetes and Hypertension Program--Balneario Camboriu/SC and received daily supplements containing 1 mg of folic acid for 3 months. DNA was previously extracted from leukocytes and the G1793A mutation was detected by PCR-RFLP. Blood samples were collected during the basal period and after supplementation for the determination of homocysteine by HPLC, and of folic acid and vitamin B(12) by RIA. The allele frequency for the G1793A mutation was 3.01% and no homozygous individuals with mutant alleles were detected. Hyperhomocysteinemia was diagnosed in 27.71% of the patients, folic acid deficiency in 15.66%, and vitamin B(12) deficiency in 7.23%. Plasma homocysteine concentrations were inversely correlated with folic acid (r = -0.27, p = 0.01) and vitamin B(12) (r = -0.21; p = 0.05) concentrations. The individuals with a heterozygous genotype for the G1793A mutation showed borderlines or deficient values in folic acid and vitamin B(12) concentrations compared to individuals with a normal genotype. Hyperhomocysteinemia and the vitamin deficiencies presented by type 2 diabetic individuals, included with a heterozygous genotype for the G1793A mutation in the MTHFR gene, reached normal values by daily folic acid supplementation.

Adult↗
PubMed2003

Effects of reducing dietary protein, methionine, choline, folic acid, and vitamin B12 during the late stages of the egg production cycle on performance and eggshell quality.

A series of four experiments was conducted to determine whether-shell quality during the late stages of egg production can be improved by using diets that are effective in reducing egg size. The experiments involved dietary manipulation of protein, methionine, choline, folic acid, and vitamin B12. In experiment 1, reducing dietary protein in combination of reducing the dietary methionine and choline or this diet without supplemental folic acid and vitamin B12 resulted in reduced egg weight and improved shell quality. However, egg production also was drastically reduced. In experiment 2, reducing the dietary level of methionine, without adding supplemental choline, folic acid, and vitamin B12 reduced egg size and improved shell quality, but egg production was reduced as well. In this experiment reducing the dietary methionine without supplemental folic acid and vitamin B12 reduced egg size and improved shell quality with no adverse effect on egg production. In experiment 3, reducing the dietary level of methionine and choline or reducing the dietary level of choline, folic acid, and vitamin B12 reduced egg size and improved shell quality without adverse effects on egg production. On the other hand, reducing dietary methionine, folic acid, vitamin B12, and supplemental choline reduced egg weight and improved shell quality but lowered egg production. In experiment 4, reducing dietary methionine together with reducing choline and vitamin B12 reduced egg size and improved shell quality with no adverse effect on egg production. The results of this series of experiments generally indicate that certain manipulations of the combination of methionine, choline, folic acid, and vitamin B12 have the potential to reduce egg weight and improve shell quality without affecting egg production during the latter stages of the egg production cycle.

Animal Feed↗
PubMed2006

Homocysteine lowering with folic acid and vitamin B supplements: effects on cardiovascular disease in older adults.

Cardiovascular disease (CVD) is the leading cause of death in older men and women and contributes significantly to morbidity in later life. Folic acid and other vitamin B deficiencies and elevated total plasma homocysteine levels are associated with increased cardiovascular risk in geriatric patients, but recent studies have questioned the importance of these risk factors in older people. Data on the effects of homocysteine-lowering therapy (e.g. folic acid and vitamin B supplements) on surrogate CVD endpoints, such as atherosclerotic progression, endothelial function, inflammation and hypercoagulation, are conflicting. Findings from randomised clinical trials using clinical CVD outcomes show that folic acid and vitamin B supplements may not provide cardiovascular protection. Furthermore, these findings raise questions about whether the combination of folic acid and B vitamins may actually be harmful. Other large randomised clinical trials are underway to help clarify the role of folic acid and vitamin B supplements in CVD prevention in older people. Data to date do not support use of homocysteine-lowering therapies in either middle-aged or older adults.

Adult↗
PubMed1995

Plasma homocysteine in acute myocardial infarction: homocysteine-lowering effect of folic acid.

OBJECTIVES: Moderate hyperhomocysteinaemia is an independent risk factor for cardiovascular disease which may be causal. We investigated whether the concentration of plasma homocysteine changes between the acute phase of myocardial infarction and follow-up, and whether treatment with oral folic acid was effective in lowering homocysteine levels in patients with myocardial infarction. DESIGN AND SUBJECTS: Plasma total homocysteine levels 24-36 h (baseline) after onset of acute myocardial infarction were compared with the levels obtained at 6 weeks' follow-up and with the levels in the controls. In the same patients, we studied the effect on plasma homocysteine of 6 weeks' treatment with daily oral folic acid doses of 2.5 or 10 mg compared to no treatment. RESULTS: At baseline, 12 of 68 patients (18%) had moderate hyperhomocysteinaemia (> 17.3 mumol L-1; P < 0.05). Between baseline and follow-up, plasma homocysteine levels increased from 13.1 +/- 4.6 to 14.8 +/- 4.8 mumol L-1 (mean +/- SD; P < 0.001). Treatment with nitroglycerin, streptokinase, beta blockers, or acetylsalicylic acid seemed not to have caused this change. Folic acid lowered plasma homocysteine in all but two of 33 treated patients with a mean decrease of 4.4 mumol L-1 (-27%; P < 0.001). There was no difference between the effect of 2.5 and 10 mg of folic acid. In the untreated group (n = 20), plasma homocysteine increased with a mean increase of 0.6 mumol L-1 (+4%; P < 0.05). CONCLUSIONS: Plasma homocysteine seems to increase in the post myocardial infarction period, the cause of which warrants further study. Folic acid appears to be an effective treatment for the reduction of both normal and increased plasma homocysteine concentrations in patients with myocardial infarction. This suggests that folic acid should be used for intervention when studying the effect of homocysteine-lowering therapy on the risk on myocardial infarction.

Adult↗
PubMed1999

Effect of folic acid and betaine on fasting and postmethionine-loading plasma homocysteine and methionine levels in chronic haemodialysis patients.

OBJECTIVES: To study fasting and postmethionine-loading (increment and decrement) plasma homocysteine levels in end-stage renal disease (ESRD) patients in relation to B-vitamin status and after folic acid treatment without or with betaine. DESIGN: Plasma total homocysteine (tHcy) and methionine levels were measured in chronic haemodialysis patients after an overnight fast, and 6 and 24 h after an oral methionine load (0.1 g kg-1). The patients were subsequently randomized to treatment with folic acid 5 mg daily with or without betaine 4 g daily, and the loading test was repeated after 12 weeks. The patients were then re-randomized to treatment with 1 or 5 mg folic acid daily for 40 weeks, after which a third loading test was performed. SETTING: Haemodialysis unit of university hospital and centre for haemodialysis. SUBJECTS: Twenty-nine consecutive maintenance (> 3 months) haemodialysis patients, not on folic acid supplementation, 26 of whom completed the study. RESULTS: At baseline, the mean fasting, the 6 h postload and the 6 h postload increment plasma tHcy levels were increased as compared with those in healthy controls (46.8 +/- 6.9 (SEM), 92.8 +/- 9.1 and 46.0 +/- 4.2 mumol L-1, respectively) and correlated with serum folate (r = -0.42, P = 0.02; r = -0.61, P = 0.001 and r = -0.54, P = 0.003, respectively), but not with vitamin B6 or vitamin B12. At week 12, these variables had all decreased significantly. Betaine did not have additional homocysteine-lowering effects. At week 52, fasting and postload tHcy levels did not differ significantly between patients on 1 or 5 mg folic acid daily. Plasma tHcy half-life and plasma methionine levels after methionine loading were not altered by folic acid treatment. CONCLUSIONS: In chronic haemodialysis patients, fasting as well as postmethionine-loading plasma tHcy levels depend on folate status and decrease after folic acid therapy. Increased postload homocysteine levels in these patients therefore do not necessarily indicate an impaired transsulphuration capacity only; alternatively, folate may indirectly influence transsulphuration. The elucidation of the complex pathogenesis of hyperhomocysteinaemia in chronic renal failure requires further investigation.

Adult↗