Pyridoxal 5 phosphate for neuroleptic-induced tardive dyskinesia

BACKGROUND

Tardive dyskinesia is a chronic and disabling abnormal movement disorder affecting the muscles of the face, neck, tongue and the limbs. It is a common side effect of long-term antipsychotic medication use in individuals with schizophrenia and other related psychotic disorders. While there are no known effective treatments for tardive dyskinesia to date, some reports suggest that pyridoxal 5 phosphate may be effective in reducing the severity of tardive dyskinesia symptoms.

OBJECTIVES

To determine the effectiveness of pyridoxal 5 phosphate (vitamin B6 or Pyridoxine or Pyridoxal phosphate) in the treatment of neuroleptic-induced tardive dyskinesia among people with schizophrenia and other related psychotic disorders.

SEARCH METHODS

The Cochrane schizophrenia group's register of clinical trials was searched (January 2013) using the phrase: [*Pyridoxal* OR *Pyridoxine* OR *P5P* OR *PLP* OR *tardoxal* OR *Vitamin B6* O *Vitamin B 6* R in title, abstract or index terms of REFERENCE, or interventions of STUDY. References of relevant identified studies were handsearched and where necessary, the first authors of relevant studies were contacted.

SELECTION CRITERIA

Studies described as randomised controlled trials comparing the effectiveness pyridoxal 5 phosphate with placebo in the treatment of neuroleptic-induced tardive dyskinesia among patients with schizophrenia.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from each selected study. For dichotomous data, we calculated risk ratios (RR) and their 95% confidence intervals (CIs) on an intention-to-treat basis based on a fixed-effect model. For continuous data, we calculated mean differences (MD) with 95% CIs, again based on a fixed-effect model. We assessed risk of bias for each included study and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to rate quality of evidence.

MAIN RESULTS

Of the 12 records retrieved by the search, three trials published in 2001, 2003 and 2007, involving 80 inpatients with schizophrenia, aged 18 to 71 years, admitted in a psychiatric facility and followed up for a period nine weeks to 26 weeks, were included. Overall, pyridoxal 5 phosphate produced a significant improvement in tardive dyskinesia symptoms when compared with placebo, assessed by a change in Extrapyramidal Symptoms Rating Scale (ESRS) scores from baseline to the end of the first phase of the included studies (2 RCTs n = 65, RR 19.97, CI 2.87 to 139.19, low quality evidence). The endpoint tardive dyskinesia score (a measure of its severity) assessed with the ESRS, was significantly lower among participants on pyridoxal 5 phosphate compared to those on placebo (2 RCTs n = 60, MD -4.07, CI -6.36 to -1.79, low quality evidence).It was unclear whether pyridoxal 5 phosphate led to more side effects (n = 65, 2 RCTs, RR 3.97, CI 0.20 to 78.59, low quality evidence) or caused deterioration in tardive dyskinesia symptoms when compared to placebo (n = 65, 2 RCTs, RR 0.16, CI 0.01 to 3.14, low quality evidence). Five participants taking pyridoxal 5 phosphate withdrew from the study because they were not willing to take more medications while none of the participants taking placebo discontinued their medications (n = 65, 2 RCTs, RR 8.72, CI 0.51 to 149.75, low quality evidence).There was no significant difference in the endpoint positive and negative psychiatric symptoms scores, measured using the Positive and Negative symptoms Scale (PANSS) between participants taking pyridoxal 5 phosphate and those taking placebo. For the positive symptoms: (n = 15, 1 RCT, MD -1.50, CI -4.80 to 1.80, low quality evidence). For negative the symptoms: (n = 15, 1 RCT, MD -1.10, CI -5.92 to 3.72, low quality evidence).

AUTHORS' CONCLUSIONS

Pyridoxal 5 phosphate may have some benefits in reducing the severity of tardive dyskinesia symptoms among individuals with schizophrenia. However, the quality of evidence supporting the effectiveness of pyridoxal 5 phosphate in treating tardive dyskinesia is low, based on few studies, short follow-up periods, small sample sizes and inadequate adherence to standardised reporting guidelines for randomised controlled trials among the included studies.

Pyridoxine induced rosacea-like dermatitis

Rosacea is a common chronic inflammatory cutaneous disease of unknown etiology, characterized by remissions and exacerbations, presenting with centrofacial erythema and telangiectasias. It affects mainly adults around the age of 30 years and classically predominates in females. The pathophysiology of rosacea has not yet been fully understood. Risk factors are positive family history, very light skin phototype, sun exposure and consumption of spicy food or alcohol. Recently, there has been some evidence that some drugs or vitamins could be potential factors that can aggravate rosacea or induce rosacea-like symptoms. In this context, we present a 53-year-old female developing rosacea-like dermatitis due to a fixed combination of isoniazid and pyridoxine, which she was receiving along with rifampicin for the treatment of pulmonary tuberculosis.

Vitamin B and its derivatives for diabetic kidney disease

BACKGROUND

Diabetes is a leading cause of end-stage kidney disease (ESKD) mainly due to development and progression of diabetic kidney disease (DKD). In absence of definitive treatments of DKD, small studies showed that vitamin B may help in delaying progression of DKD by inhibiting vascular inflammation and endothelial cell damage. Hence, it could be beneficial as a treatment option for DKD.

OBJECTIVES

To assess the benefits and harms of vitamin B and its derivatives in patients with DKD.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 29 October 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials comparing vitamin B or its derivatives, or both with placebo, no treatment or active treatment in patients with DKD. We excluded studies comparing vitamin B or its derivatives, or both among patients with pre-existing ESKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Results were reported as risk ratio (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model.

MAIN RESULTS

Nine studies compared 1354 participants randomised to either vitamin B or its derivatives with placebo or active control were identified. A total of 1102 participants were randomised to single vitamin B derivatives, placebo or active control in eight studies, and 252 participants randomised to multiple vitamin B derivatives or placebo. Monotherapy included different dose of pyridoxamine (four studies), benfotiamine (1), folic acid (1), thiamine (1), and vitamin B12 (1) while combination therapy included folic acid, vitamin B6, and vitamin B12 in one study. Treatment duration ranged from two to 36 months. Selection bias was unclear in three studies and low in the remaining six studies. Two studies reported blinding of patient, caregiver and observer and were at low risk of performance and detection bias, two studies were at high risk bias, and five studies were unclear. Attrition bias was high in one study, unclear in one study and low in seven studies. Reporting bias was high in one study, unclear in one study, and low in the remaining seven studies. Four studies funded by pharmaceutical companies were judged to be at high risk bias, three were at low risk of bias, and two were unclear.Only a single study reported a reduction in albuminuria with thiamine compared to placebo, while second study reported reduction in glomerular filtration rate (GFR) following use of combination therapy. No significant difference in the risk of all-cause mortality with pyridoxamine or combination therapy was reported. None of the vitamin B derivatives used either alone or in combination improved kidney function: increased in creatinine clearance, improved the GFR; neither were effective in controlling blood pressure significantly compared to placebo or active control. One study reported a significant median reduction in urinary albumin excretion with thiamine treatment compared to placebo. No significant difference was found between vitamin B combination therapy and control group for serious adverse events, or one or more adverse event per patient. Vitamin B therapy was reported to well-tolerated with mild side effects in studies with treatment duration of more than six months. Studies of less than six months duration did not explicitly report adverse events; they reported that the drugs were well-tolerated without any serious drug related adverse events. None of the included studies reported cardiovascular death, progression from macroalbuminuria to ESKD, progression from microalbuminuria to macroalbuminuria, regression from microalbuminuria to normoalbuminuria, doubling of SCr, and quality of life. We were not able to perform subgroup or sensitivity analyses or assess publication bias due to insufficient data.

AUTHORS' CONCLUSIONS

There is an absence of evidence to recommend the use of vitamin B therapy alone or combination for delaying progression of DKD. Thiamine was found to be beneficial for reduction in albuminuria in a single study; however, there was lack of any improvement in kidney function or blood pressure following the use of vitamin B preparations used alone or in combination. These findings require further confirmation given the limitations of the small number and poor quality of the available studies.

Association between B vitamins supplementation and risk of cardiovascular outcomes: a cumulative meta-analysis of randomized controlled trials

BACKGROUND

Observational studies suggest that B vitamin supplementation reduces cardiovascular risk in adults, but this association remains controversial. This study aimed to summarize the evidence from randomized controlled trials (RCTs) investigating B vitamin supplementation for the primary or secondary prevention of major adverse cardiovascular outcomes and to perform a cumulative meta-analysis to determine the evidence base.

METHODOLOGY AND PRINCIPAL FINDINGS

In April 2013, we searched PubMed, Embase, and the Cochrane Library to identify relevant RCTs. We included RCTs investigating the effect of B vitamin supplementation on cardiovascular outcome. Relative risk (RR) was used to measure the effect using a random-effect model. Statistical heterogeneity scores were assessed using the Q statistic. We included data on 57,952 individuals from 24 RCTs: 12 primary prevention trials and 12 secondary prevention trials. In 23 of these trials, 10,917 major adverse cardiovascular events (MACE) occurred; in 20 trials, 7,203 deaths occurred; in 15 trials, 3,422 cardiac deaths occurred; in 19 trials, 3,623 myocardial infarctions (MI) occurred; and in 18 trials, 2,465 strokes occurred. B vitamin supplementation had little or no effect on the incidence of MACE (RR, 0.98; 95% confidence interval [CI]: 0.93-1.03; P = 0.37), total mortality (RR, 1.01; 95% CI: 0.97-1.05; P = 0.77), cardiac death (RR, 0.96; 95% CI: 0.90-1.02; P = 0.21), MI (RR, 0.99; 95% CI: 0.93-1.06; P = 0.82), or stroke (RR, 0.94; 95% CI: 0.85-1.03; P = 0.18).

CONCLUSION/SIGNIFICANCE

B vitamin supplementation, when used for primary or secondary prevention, is not associated with a reduction in MACE, total mortality, cardiac death, MI, or stroke.

Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid: community-based randomized clinical trial in Italy and the Netherlands

BACKGROUND

In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.

METHODS/DESIGN

This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.

DISCUSSION

The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.

TRIAL REGISTRATION

Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161.

Association of folic acid supplementation during pregnancy and infant bronchiolitis

Viral bronchiolitis affects 20%-30% of infants; because there is no known effective treatment, it is important to identify risk factors that contribute to its pathogenesis. Although adequate folate intake during the periconceptional period prevents neural tube defects, animal data suggest that higher supplementation may be a risk factor for child respiratory diseases. Using a population-based retrospective cohort of 167,333 women and infants, born in 1995-2007 and enrolled in the Tennessee Medicaid program, we investigated the association between the filling of folic acid-containing prescriptions and infant bronchiolitis. We categorized women into the following 4 groups in relation to the first trimester: "none" (no prescription filled), "first trimester only," "after first trimester," and "both" (prescriptions filled both during and after the first trimester). Overall, 21% of infants had a bronchiolitis diagnosis, and 5% were hospitalized. Most women filled their first prescriptions after the fifth to sixth weeks of pregnancy, and most prescriptions contained 1,000 µg of folic acid. Compared with infants born to women in the "none" group, infants born to women in the "first trimester only" group had higher relative odds of bronchiolitis diagnosis (adjusted odds ratio = 1.17, 95% confidence interval: 1.11, 1.22) and greater severity (adjusted odds ratio = 1.16, 95% confidence interval: 1.11, 1.22). This study's findings contribute to an understanding of the implications of prenatal nutritional supplement recommendations for infant bronchiolitis.

Maternal folate exposure in pregnancy and childhood asthma and allergy: a systematic review

Adequate folate status in early pregnancy is critical to prevent congenital malformations, yet little is known about whether exposure to folate, specifically folic acid supplementation beyond the recommended dose, influences chronic health outcomes. The link between maternal folate levels and risk of childhood asthma and allergic disease has been investigated in 10 large prospective cohort studies that reported conflicting results. While the majority of studies reported no association, those supporting a positive relationship found a small increase in risk that was generally transient in nature, confined to early childhood, and associated with folic acid supplementation in late pregnancy. This systematic review presents background information on maternal folate exposure and childhood asthma, synthesizes the current epidemiologic evidence in the context of the methodological differences among studies and their potential limitations, and offers direction for future research.

Association between folate intake and the risk of lung cancer: a dose-response meta-analysis of prospective studies

Background

Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach.

Methodology and Principal Findings

In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer. Only prospective cohort studies that reported the effect estimates about the incidence of lung cancer with 95% confidence intervals (CIs) for more than 2 categories of folate intake were included. Overall, we examined 9 cohort studies reporting the data of 566,921 individuals. High folate intake had little effect on the risk of lung cancer (risk ratio [RR], 0.92; 95% CI, 0.84–1.01; P = 0.076). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of lung cancer (RR, 0.99; 95% CI, 0.97–1.01; P = 0.318). Subgroup analysis suggested that the potential protective effect of low folate intake (100–299 µg/day) was more evident in women than men, while the opposite was true of high folate intake (>400 µg/day). Finally, subgroup analyses of a 100 µg/day increment in folate intake indicated that its potential protective effect was more evident in men than in women.

Conclusion/Significance

Our study revealed that folate intake had little or no effect on the risk of lung cancer. Subgroup analyses indicated that an increased folate intake was associated with a reduced risk of lung cancer in men. Furthermore, low folate intake may be a protective factor for women, and high folate intake for men.

Do nutrients play a role in delirium?

PURPOSE OF REVIEW

This study will review the biologic roles of thiamine, niacin, folic acid, cobalamin, antioxidants, lipids, glucose, and water and their implications as contributors or causal agents in the development of delirium, particularly if deficiencies or excesses exist.

RECENT FINDINGS

Knowledge on how overall nutritional status and individual nutrients predispose or directly lead to the development of delirium is currently very limited. Most studies in the area of nutrition and cognition still describe mental status changes using the term dementia and do not specifically address nutrition and delirium. However, as the brain pathophysiology that accompanies delirium has been furthered elucidated, it has become clear that nutritional imbalances can lead to these same physiologic changes in neuronal tissue.

SUMMARY

Delirium, characterized by an acute change in mental status along with diminished awareness and attention and disturbances in memory, language, or perception, confers high rates of morbidity and mortality and can be difficult to both diagnose and treat. Although the cause of delirium is often multifactorial, nutritional status and nutrients may play a role in predisposing or directly causing this acute cognitive dysfunction. Many nutritional deficiencies or excesses (i.e., B vitamins, antioxidants, glucose, water, lipids) have been shown to alter the way one thinks and restoring the balance in many of these nutrients can lead to resolution of delirium.

Angioneurotic oedema secondary to oral thiamine

Although allergic side effects due to parenteral thiamine are well-documented, they are extremely rare when thiamine is used orally. We report a case of a 47-year-old woman who developed angioneurotic oedema secondary to oral ingestion of thiamine at a therapeutic dose. The incident occurred twice with a clear temporal relationship to the initiation on thiamine.

Adverse myocardial effects of B-vitamin therapy in subjects with chronic kidney disease and hyperhomocysteinaemia

BACKGROUND & AIMS

Hyperhomocysteinaemia (HHCY), a common finding in patients with chronic kidney disease (CKD), has been shown to contribute to adverse cardiac remodelling and failure. We hypothesised that in human subjects with CKD, HHCY would be associated with myocardial dysfunction, and that homocysteine (HCY)-lowering therapy would improve myocardial remodelling and heart-failure (HF) outcomes.

METHODS AND RESULTS

Post hoc analysis of the Homocysteinemia in Kidney and End Stage Renal Disease (HOST) trial (n=2056) was performed to determine if HCY-lowering therapy with high dose B vitamins affects HF outcomes in patients with CKD. In addition, effects on myocardial remodelling were assessed in a subgroup of 220 trial subjects who had transthoracic echocardiograms done before study randomisation and during the course of the study as part of their routine clinical care. HF outcomes were not significantly affected by treatment compared to the placebo. HCY levels were inversely correlated with diastolic function (R=-0.21; p=0.038). Vitamin therapy resulted in a significant increase in left atrial size (+0.15±0.8 cm vs. -0.13±0.07 cm; p=0.0095). No other echocardiographic parameters were significantly associated with baseline HCY levels or changes with vitamin therapy.

CONCLUSION

HHCY is associated with diastolic dysfunction in patients with CKD. However, B-vitamin therapy did not improve HF outcomes despite lowering of plasma HCY levels, and was associated with an increase in left atrial size, which is a surrogate for worsening left ventricular diastolic dysfunction. These findings suggest that high-dose B vitamin therapy may be harmful in patients with CKD.

Weekly iron folate supplementation in adolescent girls--an effective nutritional measure for the management of iron deficiency anaemia

INTRODUCTION

Nutritional anaemia in India is common morbidity seen in late adolescent and young female population. There are many conflicting opinions regarding dosage of iron folic acid supplementation for managing this simple nutritional deficiency disorder. Hence, this 'Randomized Controlled Trial' was undertaken in adolescent girls suffering from Iron Deficiency Anaemia visiting 'Urban Health and Training Centre' situated in urban slum area. The aim of this study was to assess the (a) Impact of weekly iron folic acid supplementation in comparison with daily iron supplementation for the management of Iron Deficiency Anaemia in adolescent girls visiting 'Urban Health and Training Centre'; (b) Adverse drug reaction profile in 'Weekly Iron Folic Acid Supplementation' and 'Daily Iron Folic Acid Supplementation' regimes; (c) Compliance profile for 'Weekly Iron Folic Acid Supplementation' and 'Daily Iron Folic Acid Supplementation' regimes in adolescent girls.

METHODS AND MATERIAL

Randomized controlled trial was conducted in adolescent girls visiting 'Urban Health and Training Centre' during the study period June, 2011 to October, 2012. The 120 anaemic (Haemoglobin < 12 gm%) adolescent girls (10-19 years) were distributed randomly by block randomization in two groups; one receiving daily Iron and Folic Acid supplementation and in other group receiving weekly Iron and Folic Acid supplementation for 3 months. All the study subjects were given de-worming (Albendazole 400 mg) and required health education separately. Both the groups were monitored for Haemoglobin estimation, compliance and adverse drug reactions, if any. Open-Epi Statistical Software was used for data analysis.

RESULTS

The mean age of study subjects in 'Daily Iron and Folic Acid Supplementation' and 'Weekly Iron and Folic Acid Supplementation' group was 13.48 and 13.55 years respectively. Their mean pre intervention Haemoglobin was 10.1±1.1 gm/dl and 10.4±1.1 gm/dl respectively. The mean rise in Haemoglobin after lean period of 1 month in respective groups was almost equal i.e. 1.0±0.7 gm/dl and 1.0±0.8 gm/dl. Adverse Drug Reactions were 8.3% in weekly regime as compared to 13.35% in daily regime, abdominal pain being the commonest adverse drug reaction seen .The compliance calculated as mean of unconsumed 'Iron and Folic Acid' tablets was 6.1±10.98 in 'Daily Iron Folic Acid Supplementation' group, while it was 1.3±3.15 in 'Weekly Iron Folic Acid Supplementation' group (p=0.0012), making weekly regime more promising than daily regime with better treatment compliance.

CONCLUSIONS

Weekly supplementation of 'Iron and Folic Acid' in 'Iron Deficiency Anaemia' patients is as good as daily supplementation with added benefits of less adverse reactions and better compliance.

Disposition and Metabolite Kinetics of Oral L-carnitine in Humans

The pharmacokinetics of L-carnitine and its metabolites were investigated in 7 healthy subjects following the oral administration of 0, 0.5, 1, and 2 g 3 times a day for 7 days. Mean plasma concentrations of L-carnitine across an 8-hour dose interval increased significantly (P < .05) from a baseline of 54.2 +/- 9.3 microM to 80.5 +/- 12.5 microM following the 0.5-g dose; there was no further increase at higher doses. There was a significant increase (P < .001) in the renal clearance of L-carnitine indicating saturation of tubular reabsorption. Trimethylamine plasma levels increased proportionately with L-carnitine dose, but there was no change in renal clearance. A significant increase in the plasma concentrations of trimethylamine-N-oxide from baseline was evident only for the 2-g dose of L-carnitine (from 34.5 +/- 2.0 to 149 +/- 145 microM), and its renal clearance decreased with increasing dose (P < .05). There was no evidence for nonlinearity in the metabolism of trimethylamine to trimethylamine-N-oxide. In conclusion, the pharmacokinetics of oral L-carnitine display nonlinearity above a dose of 0.5 g 3 times a day.

B vitamin intakes and incidence of colorectal cancer: results from the Women's Health Initiative Observational Study cohort

BACKGROUND

The role of one-carbon metabolism nutrients in colorectal carcinogenesis is not fully understood. Associations might be modified by mandated folic acid (FA) fortification or alcohol intake.

OBJECTIVE

We investigated associations between intakes of folate, riboflavin, vitamin B-6, and vitamin B-12 and colorectal cancer (CRC) in the Women's Health Initiative Observational Study, stratified by time exposed to FA fortification and alcohol intake.

DESIGN

A total of 88,045 postmenopausal women were recruited during 1993-1998; 1003 incident CRC cases were ascertained as of 2009. Quartiles of dietary intakes were compared; HRs and 95% CIs were estimated by Cox proportional hazards models.

RESULTS

Dietary and total intakes of vitamin B-6 in quartile 4 compared with quartile 1 (HR: 0.80; 95% CI: 0.66, 0.97 and HR: 0.80; 95% CI: 0.66, 0.99, respectively) and total intakes of riboflavin (HR: 0.81; 95% CI: 0.66, 0.99) were associated with reduced risk of CRC overall and of regionally spread disease. In current drinkers who consumed <1 drink (13 g alcohol)/wk, B vitamin intakes were inversely associated with CRC risk (P-interaction < 0.05). Dietary folate intake was positively associated with CRC risk among women who had experienced the initiation of FA fortification for 3 to <9 y (P-interaction < 0.01).

CONCLUSIONS

Vitamin B-6 and riboflavin intakes from diet and supplements were associated with a decreased risk of CRC in postmenopausal women. Associations of B vitamin intake were particularly strong for regional disease and among women drinkers who consumed alcohol infrequently. Our study provides new evidence that the increased folate intake during the early postfortification period may have been associated with a transient increase in CRC risk.

Efficacy and tolerability of topical 0.2% Myrtacine® and 4% vitamin PP for prevention and treatment of retinoid dermatitis in patients with mild to moderate acne

AIM

The aim of the present study was to evaluate the efficacy and tolerability of an emulsion of 0.2% Myrtacine® and 4% vitamin PP, compared with a simple emollient cream, in the treatment of retinoid dermatitis in patients with mild-to-moderate acne.

METHODS

This was a prospective, multicenter, open-label, non-randomised, parallel-group study. Patients (age 12-49 years; skin phototype I-IV) with mild-to-moderate acne, who were treated with a topical retinoid for at least one month and had developed skin irritation were assigned to one of the two following treatments: 0.2% Myrtacine® and 4% vitamin PP (N.=116) or a simple emollient cream (N.=48). Both treatments were administered twice daily, 1-1.5 hours after the application of the topical retinoid. Study endpoints were improvement in signs and symptoms of retinoid dermatitis, global efficacy, reduction in acne severity, overall clinical outcome, patient satisfaction and tolerability.

RESULTS

At day 28, compared with the simple emollient cream, 0.2% Myrtacine® and 4% vitamin PP significantly decreased signs (erythema, dryness/scaling, oedema, and roughness) and symptoms (itching, stinging, burning sensation and discomfort) of retinoid dermatitis (P<0.01). In addition, compared with the simple emollient cream, 0.2% Myrtacine® and 4% vitamin PP decreased acne severity in a significantly greater proportion of patients (P=0.023) and was associated with a better clinical outcome (mild, intermediate, clinically relevant or global improvement; P<0.001). 0.2% Myrtacine® and 4% vitamin PP was also associated with greater patient satisfaction and was better tolerated than the simple emollient cream.

CONCLUSION

0.2% Myrtacine® and 4% vitamin PP was effective and well tolerated in the treatment of retinoid dermatitis in patients with mild-to-moderate acne and significantly improved acne severity and overall clinical outcome.

Status of B-vitamins and homocysteine in diabetic retinopathy: association with vitamin-B12 deficiency and hyperhomocysteinemia

Diabetic retinopathy (DR) is a common cause of blindness. Although many studies have indicated an association between homocysteine and DR, the results so far have been equivocal. Amongst the many determinants of homocysteine, B-vitamin status was shown to be a major confounding factor, yet very little is known about its relationship to DR. In the present study, we, therefore, investigated the status of B-vitamins and homocysteine in DR. A cross-sectional case–control study was conducted with 100 normal control (CN) subjects and 300 subjects with type-2 diabetes (T2D). Of the 300 subjects with T2D, 200 had retinopathy (DR) and 100 did not (DNR). After a complete ophthalmic examination including fundus fluorescein angiography, the clinical profile and the blood levels of all B-vitamins and homocysteine were analyzed. While mean plasma homocysteine levels were found to be higher in T2D patients compared with CN subjects, homocysteine levels were particularly high in the DR group. There were no group differences in the blood levels of vitamins B1 and B2. Although the plasma vitamin-B6 and folic acid levels were significantly lower in the DNR and DR groups compared with the CN group, there were no significant differences between the diabetes groups. Interestingly, plasma vitamin-B12 levels were found to be significantly lower in the diabetes groups compared with the CN group; further, the levels were significantly lower in the DR group compared with the DNR group. Higher homocysteine levels were significantly associated with lower vitamin-B12 and folic acid but not with other B-vitamins. Additionally, hyperhomocysteinemia and vitamin-B12 deficiency did not seem to be related to subjects' age, body mass index, or duration of diabetes. These results thus suggest a possible association between vitamin-B12 deficiency and hyperhomocysteinemia in DR. Further, the data indicate that vitamin-B12 deficiency could be an independent risk factor for DR.

Folic acid in pregnancy - is there a link with childhood asthma or wheeze?

BACKGROUND

Folic acid supplementation has an established role in early pregnancy for preventing neural tube defects. However, there is controversy over a possible link between late pregnancy folic acid supplementation and childhood asthma.

OBJECTIVE

To review the evidence exploring the association between maternal folate exposure in pregnancy and childhood asthma or wheeze.

RESULTS

Four relevant observational studies were identified. Two found statistically significant associations between childhood asthma and late (but not early) pregnancy maternal folic acid exposure. Another found a statistically significant association between childhood wheeze and early (but not late) pregnancy maternal folic acid exposure. A fourth study found little association between maternal dietary folate in pregnancy and infantile wheeze.

DISCUSSION

The currently available evidence regarding an association between folate in pregnancy and childhood asthma or wheeze is conflicting. We offer suggestions for discussing the potential risk with patients and recommend further research on this subject be conducted.

A case for immediate-release niacin

Niacin is currently a favored drug for increasing high-density lipoprotein, especially in patients with ischemic heart disease or at high risk of developing it. In addition, niacin further decreases low-density lipoprotein in statin-treated patients and has been shown to reduce morbidity and mortality. Among the available niacin preparations, crystalline, immediate-release niacin is the most effective for increasing high-density lipoprotein and is relatively free of hepatic toxicity. We present the case of a patient who had an excellent clinical and laboratory response to 3 g daily of immediate-release niacin, but who later developed clinical hepatitis when he inadvertently switched to the same dose of slow-release niacin. We encourage the use of niacin in general, immediate-release niacin in particular, and caution that niacin is a drug and not a dietary supplement. We also present practical steps for starting niacin, including close patient contact and support, and beginning with a therapeutic dose of 2 g per day right from the start.

Folic acid food fortification-its history, effect, concerns, and future directions

Periconceptional intake of folic acid is known to reduce a woman’s risk of having an infant affected by a neural tube birth defect (NTD). National programs to mandate fortification of food with folic acid have reduced the prevalence of NTDs worldwide. Uncertainty surrounding possible unintended consequences has led to concerns about higher folic acid intake and food fortification programs. This uncertainty emphasizes the need to continually monitor fortification programs for accurate measures of their effect and the ability to address concerns as they arise. This review highlights the history, effect, concerns, and future directions of folic acid food fortification programs.