A 12 week double-blind randomised controlled trial investigating the effect of dietary supplementation with 5000 IU/day (125 µg/day) vitamin D in adults with asthma, led to an improvement in the lung function parameter - FEV1:FVC ratio.

Vitamin D deficiency has previously been linked to higher rates of exacerbation and reduced lung function in asthmatics. Previous randomised controlled trials (RCT) investigating the effect of vitamin D supplementation have mainly focussed on children with asthma. Trials involving adults have typically used bolus dosing regimes and the main outcomes have been patient focussed without investigating underlying inflammation. The present study aimed to conduct a 12-week placebo-controlled RCT administering a daily 5000 IU (125 µg) vitamin D3 supplement to adults with mild to moderate asthma. A total of 32 participants were randomised to receive either the 5000 IU vitamin D3 supplement or an identical matching placebo. The primary outcome of the study was lung function measured by ratio of FEV1:FVC (effect size 2.5) with secondary outcomes including asthma symptoms and inflammatory biomarkers. There was a small but statistically significant higher increase in the mean (± SD) ratio of FEV1: FVC from baseline to post-intervention in the vitamin D group (+ 0.05 ± 0.06) compared to the placebo group (+ 0.006 ± 0.04, p = 0.04). There was no effect of the intervention on asthma control test scores, or the inflammatory biomarkers measured. There was a moderate, significant association between baseline plasma 25(OH)D concentration and baseline plasma IL-10 (r = 0.527, p = 0.005) and TNF-α (r = -0.498. p = 0.008) concentrations. A daily vitamin D3 supplement led to slightly improved lung function in adult asthmatics and may be a useful adjunct to existing asthma control strategies, particularly for individuals with suboptimal vitamin D status.

Effect of vitamin D3 supplementation on cardiometabolic disease risk among overweight/obese adult males in the UK: A pilot randomised controlled trial.

BACKGROUND: Observational studies suggest links between reduced serum 25(OH)D concentration and increased cardiometabolic disease risk. However, these studies provide limited evidence of causation, with few conclusive randomised controlled trials (RCT) having been carried out to date. This RCT investigated the effect of vitamin D3 supplementation on vascular function and cardiometabolic disease risk markers, in 55 healthy males aged 18-65 years with plasma 25(OH)D concentration <75 mol L-1 and body mass index ≥24.9 kg m-2 . METHODS: Participants were assigned to consume 125 µg day-1 (5000 IU day-1 ) vitamin D3 or placebo for 8 weeks. Blood samples and vascular function measures were obtained at baseline, as well as at weeks 4 and 8. The primary outcome was arterial stiffness, an indicator of cardiovascular disease (CVD) risk, assessed by pulse wave velocity. Biomarkers of CVD risk, insulin resistance and endothelial function were measured using an enzyme-linked immunosorbent assay. RESULTS: Daily oral intake of 125 µg supplemental vitamin D3 led to a significant improvement in plasma 25(OH)D concentrations over the 8-week intervention in the vitamin D group compared to the change in the placebo group (p ˂ 0.001). In the vitamin D group, the baseline mean ± SD 25(OH)D concentration was 38.4 ± 15.9 and this increased to 72.8 ± 16.1 nmol L-1 after 8 weeks of supplementation. The intervention had no effect on arterial stiffness, as measured by pulse wave velocity, although vitamin D3 supplementation did lead to a decrease in mean ± SD brachial pulse pressure from baseline to 8 weeks of -2.9 ± 3.4 mmHg (p = 0.027) in the vitamin D group compared to the same period in the placebo group. The intervention had no effect on the remaining cardiometabolic parameters. CONCLUSIONS: Overall, treatment significantly improved brachial pulse pressure but no other cardiometabolic disease risk markers. To follow on from this pilot RCT, future large-scale clinical trials over longer durations may offer further insights.

Interlaboratory comparison of 25-hydroxyvitamin D assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 2 ligand binding assays - impact of 25-hydroxyvitamin D2 and 24R,25-dihydroxyvitamin D3 on assay performance.

An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of ligand binding assays (Part 2) for the determination of serum total 25-hydroxyvitamin D [25(OH)D]. Fifty single-donor samples were assigned target values for concentrations of 25-hydroxyvitamin D2 [25(OH)D2], 25-hydroxyvitamin D3 [25(OH)D3], 3-epi-25-hydroxyvitamin D3 [3-epi-25(OH)D3], and 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3] using isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS). VDSP Intercomparison Study 2 Part 2 includes results from 17 laboratories using 32 ligand binding assays. Assay performance was evaluated using mean % bias compared to the assigned target values and using linear regression analysis of the test assay mean results and the target values. Only 50% of the ligand binding assays achieved the VDSP criterion of mean % bias ≤ |± 5%|. For the 13 unique ligand binding assays evaluated in this study, only 4 assays were consistently within ± 5% mean bias and 4 assays were consistently outside ± 5% mean bias regardless of the laboratory performing the assay. Based on multivariable regression analysis using the concentrations of individual vitamin D metabolites in the 50 single-donor samples, most assays underestimate 25(OH)D2 and several assays (Abbott, bioMérieux, DiaSorin, IDS-EIA, and IDS-iSYS) may have cross-reactivity from 24R,25(OH)2D3. The results of this interlaboratory study represent the most comprehensive comparison of 25(OH)D ligand binding assays published to date and is the only study to assess the impact of 24R,25(OH)2D3 content using results from a reference measurement procedure.

Assessment of serum total 25-hydroxyvitamin D assays for Vitamin D External Quality Assessment Scheme (DEQAS) materials distributed at ambient and frozen conditions.

The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at -40 °C prior to distribution and the participants are instructed to store the samples frozen at -20 °C or lower after receipt; however, the samples are shipped to participants at ambient conditions (i.e., no temperature control). To address the question of whether shipment at ambient conditions is sufficient for reliable performance of various 25(OH)D assays, the equivalence of DEQAS human serum samples shipped under frozen and ambient conditions was assessed. As part of a Vitamin D Standardization Program (VDSP) commutability study, two sets of the same nine DEQAS samples were shipped to participants at ambient temperature and frozen on dry ice. Twenty-eight laboratories participated in this study and provided 34 sets of results for the measurement of 25(OH)D using 20 ligand binding assays and 14 liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Equivalence of the assay response for the frozen versus ambient DEQAS samples for each assay was evaluated using multi-level modeling, paired t-tests including a false discovery rate (FDR) approach, and ordinary least squares linear regression analysis of frozen versus ambient results. Using the paired t-test and confirmed by FDR testing, differences in the results for the ambient and frozen samples were found to be statistically significant at p < 0.05 for four assays (DiaSorin, DIAsource, Siemens, and SNIBE prototype). For all 14 LC-MS/MS assays, the differences in the results for the ambient- and frozen-shipped samples were not found to be significant at p < 0.05 indicating that these analytes were stable during shipment at ambient conditions. Even though assay results have been shown to vary considerably among different 25(OH)D assays in other studies, the results of this study also indicate that sample handling/transport conditions may influence 25(OH)D assay response for several assays.

N-3 fatty acid supplementation mediates lipid profile, including small dense LDL, when combined with statins: a randomized double blind placebo controlled trial.

BACKGROUND: Epidemiological and clinical evidence suggests that high-dose intake of omega 3 fatty acids (n-3 FA) have a favorable role in altering serum triglycerides (TG) and non-high density lipoprotein cholesterol (non-HDL-C) when combined with statins in hyperlipidemic patients. Their efficacy in altering low-density lipoprotein cholesterol (LDL-C) particle size is yet to be established. AIM: This study evaluated the effects of supplementing 4 g/day Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) on serum blood lipids, including small, dense LDL-C particle concentration, in hyperlipidemic patients receiving stable statin therapy. METHODS: In this randomized, placebo-controlled, double-blind parallel group study, 44 patients on statin therapy for > 8 weeks with non-HDL-C concentrations above 130 mg/dL were randomized into two groups. For 8 weeks, together with their prescribed statin, the intervention group received 4 g/day EPA + DHA (3000 mg EPA + 1000 mg DHA in ethyl ester form) and the placebo group received 4 g/day olive oil (OO). Measurements of serum non-HDL-C, TG, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C (including large - LDL I; intermediate - LDL II; and small - LDL III subclasses), very-low-density lipoprotein cholesterol (VLDL-C) concentration, were taken at baseline and post-intervention. Dietary intake was assessed with a weighed intake, 3-day food diary at week 4. Primary outcome measures were percent change in LDL III, non-HDL-C and LDL particle number. RESULTS: At the end of treatment, the median percent change in serum LDL III concentration was significantly greater in the n-3 FA group plus atorvastatin compared to placebo (- 67.5% vs - 0%, respectively; P < 0.001). Supplementation with n-3 FA plus atorvastatin led to significant reductions in serum non-HDL-C (- 9.5% vs 4.7%, P < 0.01), TG (- 21.5% vs 6.2%, P < 0.001) and VLDL-C (- 36.9% vs 4.0%, P < 0.001) and TC (- 6.6% vs 2.1%, P < 0.001). Between the groups, no significant difference in percent change in the serum concentration of LDL-C, HDL-C, as well as in the LDL I and LDL II subclasses was observed. CONCLUSION: In this group of hyperlipidemic patients on a stable statin prescription, OM3 plus atorvastatin improved small dense LDL concentrations, non-HDL-C, VLDL-C and TG to a greater extent than atorvastatin alone. Further studies are warranted in this area. TRIAL REGISTRATION: This trial was retrospectively registered on 23 May 2019 on ClinicalTrials.gov with ID: NCT03961763.

Assessment of serum total 25-hydroxyvitamin D assay commutability of Standard Reference Materials and College of American Pathologists Accuracy-Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) materials: Vitamin D Standardization Program (VDSP) Commutability Study 2.

An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum total 25-hydroxyvitamin D [25(OH)D] using ligand binding assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A set of 50 single-donor serum samples were assigned target values for 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] using reference measurement procedures (RMPs). SRM and PT/EQA samples evaluated included SRM 972a (four levels), SRM 2973, six College of American Pathologists (CAP) Accuracy-Based Vitamin D (ABVD) samples, and nine Vitamin D External Quality Assessment Scheme (DEQAS) samples. Results were received from 28 different laboratories using 20 ligand binding assays and 14 LC-MS/MS methods. Using the test assay results for total serum 25(OH)D (i.e., the sum of 25(OH)D2 and 25(OH)D3) determined for the single-donor samples and the RMP target values, the linear regression and 95% prediction intervals (PIs) were calculated. Using a subset of 42 samples that had concentrations of 25(OH)D2 below 30 nmol/L, one or more of the SRM and PT/EQA samples with high concentrations of 25(OH)D2 were deemed non-commutable using 5 of 11 unique ligand binding assays. SRM 972a (level 4), which has high exogenous concentration of 3-epi-25(OH)D3, was deemed non-commutable for 50% of the LC-MS/MS assays.

A validated FFQ to determine dietary intake of vitamin D.

OBJECTIVE: The aim of the present study was to develop and validate a vitamin D FFQ for assessment of dietary vitamin D intake in healthy adults in England, UK. DESIGN: The current study assessed the agreement between a four-day food diary (4 d-FD) and a new vitamin D FFQ to measure dietary intake of vitamin D. Dietary intake was estimated using Nutritics dietary analysis software, and Spearman's and Bland-Altman tests were utilised to assess correlation and agreement, respectively. Participants also provided a blood sample for plasma analysis of vitamin D concentrations. SETTING: Home setting. PARTICIPANTS: Fifty participants were recruited to the study from the University of Chester and vicinity. RESULTS: Results showed a strong correlation between vitamin D intake recorded by the FFQ and the 4 d-FD (r = 0·609; P < 0·0001) within 95 % limits of agreement. Furthermore, a significant correlation between plasma 25(OH)D concentrations and vitamin D intake measured by the FFQ (r = 0·290, P = 0·041) and the 4 d-FD (r = 0·360, P = 0·01) was observed. CONCLUSION: Our analysis suggests this FFQ is a useful and rapid tool for researchers and health professionals to assess vitamin D dietary intakes in healthy adults in the UK.

Vitamin D3 supplementation for 8 weeks leads to improved haematological status following the consumption of an iron-fortified breakfast cereal: a double-blind randomised controlled trial in iron-deficient women.

The effect of 38 µg (1500 IU) daily vitamin D3 supplementation, consumed with an Fe-fortified breakfast cereal for 8 weeks, on haematological indicators in Fe-deficient female subjects was investigated. Fifty Fe-deficient subjects (plasma ferritin concentration <20 µg/l; mean age: 27·4 (sd 9·4) years) were randomised to consume an Fe-fortified breakfast cereal containing 9 mg of Fe daily, with either a vitamin D3 supplement or placebo. Blood samples were collected at baseline, interim (4 weeks) and post-intervention (8 weeks) for measurement of Fe and vitamin D status biomarkers. The effect of intervention was analysed using mixed-model repeated-measures ANOVA. Significant increases were observed in two main haematological indices: Hb concentration and haematocrit level from baseline to post-intervention in the vitamin D group but not in the placebo group. The increase from baseline to post-intervention in Hb concentration in the vitamin D group (135 (sd 11) to 138 (sd 10) g/l) was significantly higher compared with the placebo group (131 (sd 15) to 128 (sd 13) g/l) (P=0·037). The increase in haematocrit level from baseline to post-intervention was also significantly higher in the vitamin D group (42·0 (sd 3·0) to 43·8 (sd 3·4) %) compared with the placebo group (41·2 (sd 4·3) to 40·7 (sd 3·6) %) (P=0·032). Despite the non-significant changes in plasma ferritin concentration, this study demonstrates that 38 µg supplemental vitamin D, consumed daily, with Fe-fortified breakfast cereal led to improvement in Hb concentration and haematocrit levels in women with low Fe stores. These findings may have therapeutic implications in the recovery of Fe status in Fe-deficient populations at a healthcare level.

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H2/Ar and H2/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition.

Microwave (MW) activated H2/Ar (and H2/Kr) plasmas operating under powers and pressures relevant to diamond chemical vapor deposition have been investigated experimentally and by 2-D modeling. The experiments return spatially and wavelength resolved optical emission spectra of electronically excited H2 molecules and H and Ar(/Kr) atoms for a range of H2/noble gas mixing ratios. The self-consistent 2-D( r, z) modeling of different H2/Ar gas mixtures includes calculations of the MW electromagnetic fields, the plasma chemistry and electron kinetics, heat and species transfer and gas-surface interactions. Comparison with the trends revealed by the spatially resolved optical emission measurements and their variations with changes in process conditions help guide identification and refinement of the dominant plasma (and plasma emission) generation mechanisms and the more important Ar-H, Ar-H2, and H-H2 coupling reactions. Noble gas addition is shown to encourage radial expansion of the plasma, and thus to improve the uniformity of the H atom concentration and the gas temperature just above the substrate. Noble gas addition in the current experiments is also found to enhance (unwanted) sputtering of the copper base plate of the reactor; the experimentally observed increase in gas phase Cu* emission is shown to correlate with the near substrate ArH+ (and KrH+) ion concentrations returned by the modeling, rather than with the relatively more abundant H3+ (and H3O+) ions.

Imaging and Modeling the Optical Emission from CH Radicals in Microwave Activated C/H Plasmas.

We report a combined experimental/modeling study of optical emission from the A2Δ, B2Σ-, and C2Σ+ states of the CH radical in microwave (MW) activated CH4/H2 gas mixtures operating under a range of conditions relevant to the chemical vapor deposition of diamond. The experiment involves spatially and wavelength resolved imaging of the CH(C → X), CH(B → X), and CH(A → X) emissions at different total pressures, MW powers, C/H ratios in the source gas, and substrate diameters. The results are interpreted by extending an existing 2D (r, z) plasma model to include not just electron impact excitation but also chemiluminescent (CL) bimolecular reactions as sources of the observed CH emissions. Three possible CL reactions (of H atoms with CH2(a1A1) and CH2(X3B1) radicals and of C(1D) atoms with H2) are identified as plausible sources of electronically excited CH radicals (particularly of the lowest energy CH(A) state radicals). Each or all of these could contribute to the observed emissions and, collectively, are deduced to be the major source of the CH(A) emissions observed at the high temperatures (Tgas ∼ 3000 K) and pressures (75 ≤ p ≤ 275 Torr) explored in the present study. We suggest that such CL contributions are likely to be commonplace in such high pressure, high temperature plasma environments and highlight some of the risks associated with using relative emission intensities as an indicator of the electron characteristics in such plasmas.

Spatially Resolved Optical Emission and Modeling Studies of Microwave-Activated Hydrogen Plasmas Operating under Conditions Relevant for Diamond Chemical Vapor Deposition.

A microwave (MW) activated hydrogen plasma operating under conditions relevant to contemporary diamond chemical vapor deposition reactors has been investigated using a combination of experiment and self-consistent 2-D modeling. The experimental study returns spatially and wavelength resolved optical emission spectra of the d → a (Fulcher), G → B, and e → a emissions of molecular hydrogen and of the Balmer-α emission of atomic hydrogen as functions of pressure, applied MW power, and substrate diameter. The modeling contains specific blocks devoted to calculating (i) the MW electromagnetic fields (using Maxwell's equations) self-consistently with (ii) the plasma chemistry and electron kinetics, (iii) heat and species transfer, and (iv) gas-surface interactions. Comparing the experimental and model outputs allows characterization of the dominant plasma (and plasma emission) generation mechanisms, identifies important coupling reactions between hydrogen atoms and molecules (e.g., the quenching of H( n > 2) atoms and electronically excited H2 molecules (H2*) by the alternate ground-state species and H3+ ion formation by the associative ionization reaction of H( n = 2) atoms with H2), and illustrates how spatially resolved H2* (and Hα) emission measurements offer a detailed and sensitive probe of the hyperthermal component of the electron energy distribution function.

A case of intussusception secondary to a metastatic malignant melanoma from the nasal cavity.

About 5% of all intussusception are found in adults, up to 90% of these have an anatomical lesion with ~50% of them are malignant. Malignant melanoma commonly metastasizes to the small bowel; however, melanoma causing intussusception is rare. We describe a 57-year-old lady with a history of surgically treated malignant melanoma in her nasal cavity who came with an ambiguous intestinal obstruction. Computed tomography reported ileal-ileal intussusception, which was surgically removed via emergency open laparotomy and bowel resection. Intraoperatively the intussusception was 110 cm from the ileo-cecal valve with multiple palpable lymph nodes. Histopathology confirmed the origin as malignant melanoma with lymphovascular invasion. Our literature review found the mean prevalence of intussusception secondary to melanoma was 6.924% (SD ± 5.155). Minimally invasive techniques are reported non-inferior to open laparotomy. We argue that the open technique can provide informed decisions for adequate resection of affected bowel and lymphatic drainage.

Riboflavin depletion impairs cell proliferation in adult human duodenum: identification of potential effectors.

BACKGROUND AND AIMS: Riboflavin (vitamin B2) is an essential dietary component with a known function in oxidative metabolism. Our previous data using a rat model of riboflavin deficiency suggested that riboflavin also functions as a luminal signaling molecule regulating crypt development and cell turnover. Riboflavin deficiency is prevalent in both high- and low-income countries across the globe. This study aims to establish whether riboflavin deficiency has consequences for gastrointestinal (GI) morphology in adults and what the effects and effectors of any such alteration may be. METHODS: Duodenal biopsies and blood samples were collected from a cross-section of gastroscopy patients. Crypt morphology and cell division were studied by immunohistochemistry, and biochemical riboflavin status was determined. Additionally a cell culture model of riboflavin deficiency was developed and analyzed using a combination of flow cytometry, and microarray and clonogenic assays. RESULT: Duodenal crypts from subjects in the lowest quartile of riboflavin status were significantly shorter (P=0.023), less cellular (P=0.007), and had fewer cell divisions (P=0.034) than the crypts of subjects in the top quartile of riboflavin status. Following riboflavin depletion of colon cells in culture, cell cycle slowed. Microscopy revealed impaired mitosis and accumulation of aneuploid cells. Alterations in gene expression profiles reflected this alteration, with several mitosis-related genes altered, including AspM, cyclin B1, and Birc5 downregulated and Kif23 upregulated. Riboflavin depletion in vitro caused irreversible loss of proliferative potential of cells. CONCLUSIONS: Riboflavin depletion in adult humans impairs proliferation and proliferative potential of intestinal cells, which may have implications for gastrointestinal function.

Estimation of cis-9, trans-11 conjugated linoleic acid content in UK foods and assessment of dietary intake in a cohort of healthy adults.

Dietary conjugated linoleic acid (CLA) from ruminant-derived foods may be potentially beneficial to health. The quantity of cis-9, trans-11 CLA and trans-10, cis-12 CLA in a range of UK foodstuffs (112 foods) was determined using triple-column silver ion HPLC. The cis-9, trans-11 CLA content ranged from 1.9 mg/g lipid (mild Cheddar) to 7.3 mg/g lipid (processed cheese) in cheeses, from 0.9 mg/g lipid (ice cream) to 3.7 mg/g lipid (double cream) in non-cheese dairy products, and from 2.9 mg/g lipid (Swedish meatballs) to 6.0 mg/g lipid (minced lamb) in meat products. cis-9, trans-11 CLA concentrations for chocolate and sweets ranged from 0.1 mg/g lipid (hot chocolate) to 4.8 mg/g lipid (buttermint). The trans-10, cis-12 CLA isomer was undetected or negligible in the food samples examined. To provide information about dietary cis-9, trans-11 CLA intakes in the UK, a study was performed to estimate the daily intake of CLA in a cohort of eighteen healthy volunteers (nine female and nine male; aged 21-60 years; mean BMI = 24.0 kg/m2 (sd 2.2)) with a 7-d weighed food record. This information combined with the CLA isomer contents of UK foodstuffs was used to estimate the daily intake of the cohort. The mean daily intake of cis-9, trans-11 CLA was estimated to be 97.5 (sd 73.3) mg/d. Due to its potential health benefits, it is important to determine the CLA content of food and dietary intake as these data will be useful in determining the role of CLA in health and disease.

Effects of methodological variation on assessment of riboflavin status using the erythrocyte glutathione reductase activation coefficient assay.

Riboflavin status is usually measured as the in vitro stimulation with flavin adenine dinucleotide of the erythrocyte enzyme glutathione reductase, and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). This method is used for the National Diet and Nutrition Surveys (NDNS) of the UK. In the period between the 1990 and 2003 surveys of UK adults, the estimated prevalence of riboflavin deficiency, expressed as an EGRAC value > or = 1.30, increased from 2 to 46 % in males and from 1 to 34 % in females. We hypothesised that subtle but important differences in the detail of the methodology between the two NDNS accounted for this difference. We carried out an evaluation of the performance of the methods used in the two NDNS and compared against an 'in-house' method, using blood samples collected from a riboflavin intervention study. Results indicated that the method used for the 1990 NDNS gave a significantly lower mean EGRAC value than both the 2003 NDNS method and the 'in-house' method (P < 0.0001). The key differences between the methods relate to the concentration of FAD used in the assay and the duration of the period of incubation of FAD with enzyme. The details of the EGRAC method should be standardised for use in different laboratories and over time. Additionally, it is proposed that consideration be given to re-evaluating the basis of the EGRAC threshold for riboflavin deficiency.

Study Protocol: randomised controlled trial to investigate the functional significance of marginal riboflavin status in young women in the UK (RIBOFEM).

BACKGROUND: The functional significance of moderate riboflavin deficiency as it is currently assessed is not well understood. Animal and human studies have suggested a role for riboflavin in the absorption and mobilisation of iron and as such may be important in maintaining haematological status. Recent National Diet and Nutrition Surveys in the United Kingdom have shown that young women in particular are at risk of moderate riboflavin deficiency and low iron status. METHODS/DESIGN: A randomised placebo controlled intervention trial was conducted to investigate the effect of riboflavin supplementation on various measures of haematological status in a group of moderately riboflavin deficient young women aged 19 to 25 years. Women who were low milk consumers were initially screened for riboflavin status as assessed by the erythrocyte glutathione reductase activation coefficient assay (EGRAC). One hundred and twenty three women with EGRAC values >1.40 were randomised to receive 2 mg, 4 mg riboflavin or placebo for 8 weeks. In addition 36 of these women were randomly allocated to an iron bioavailability study to investigate the effect of the intervention on the absorption or utilisation of iron using an established red cell incorporation technique. DISCUSSION: One hundred and nineteen women completed the intervention study, of whom 36 completed the bioavailability arm. Compliance was 96 +/- 6% (mean +/- SD). The most effective recruitment strategy for this gender and age group was e-communication (e-mail and website). The results of this study will clarify the functional significance of the current biochemical deficiency threshold for riboflavin status and will inform a re-evaluation of this biochemical threshold. TRIAL REGISTRATION: Current Controlled Trials Registration No. ISRCTN35811298.

Impact of vitamin D supplementation on endothelial and inflammatory markers in adults: A systematic review.

This systematic review aims to evaluate randomised controlled trials (RCTs) investigating the effect of vitamin D supplementation on endothelial function and inflammation in adults. An electronic search of published randomised controlled trials, using Cochrane, Pubmed and Medline databases was conducted, with the search terms related to vitamin D and endothelial function. Inclusion criteria were RCTs in adult humans with a measure of vitamin D status using serum/plasma 25(OH)D and studies which administered the intervention through the oral route. Among the 1107 studies retrieved, 29 studies met the full inclusion criteria for this systematic review. Overall, 8 studies reported significant improvements in the endothelial/inflammatory biomarkers/parameters measured. However, in 2 out of the 8 studies, improvements were reported at interim time points, but improvements were absent post-intervention. The remaining 21 trial studies did not show significant improvements in the markers of interest measured. Evidence from the studies included in this systematic review did not demonstrate that vitamin D supplementation in adults, results in an improvement in circulating inflammatory and endothelial function biomarkers/parameters. This systematic review does not therefore support the use of vitamin D supplementation as a therapeutic or preventative measure for CVD in this respect.

What [plasma used for growing] diamond can shine like flame?

Diamond synthesis by chemical vapour deposition (CVD) from carbon-containing gas mixtures has by now long been an industrial reality, but commercial interest and investment into the technology has grown dramatically in the last several years. This Feature Article surveys recent advances in our understanding of the gas-phase chemistry of microwave-activated methane/hydrogen plasmas used for diamond CVD, including that of added boron-, nitrogen- and oxygen-containing dopant species. We conclude by considering some of the remaining challenges in this important area of contemporary materials science.

A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope.

Background: Tea has been shown to be a potent inhibitor of nonheme iron absorption, but it remains unclear whether the timing of tea consumption relative to a meal influences iron bioavailability.Objective: The aim of the study was to investigate the effect of a 1-h time interval of tea consumption on nonheme iron absorption in an iron-containing meal in a cohort of iron-replete, nonanemic female subjects with the use of a stable isotope (57Fe).Design: Twelve women (mean ± SD age: 24.8 ± 6.9 y) were administered a standardized porridge meal extrinsically labeled with 4 mg 57Fe as FeSO4 on 3 separate occasions, with a 14-d time interval between each test meal (TM). The TM was administered with water (TM-1), with tea administered simultaneously (TM-2), and with tea administered 1 h postmeal (TM-3). Fasted venous blood samples were collected for iron isotopic analysis and measurement of iron status biomarkers. Fractional iron absorption was estimated by the erythrocyte iron incorporation method.Results: Iron absorption was 5.7% ± 8.5% (TM-1), 3.6% ± 4.2% (TM-2), and 5.7% ± 5.4% (TM-3). Mean fractional iron absorption was found to be significantly higher (2.2%) when tea was administered 1 h postmeal (TM-3) than when tea was administered simultaneously with the meal (TM-2) (P = 0.046). An ∼50% reduction in the inhibitory effect of tea (relative to water) was observed, from 37.2% (TM-2) to 18.1% (TM-3).Conclusions: This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency. This trial was registered at clinicaltrials.gov as NCT02365103.