Unconditional cash transfers reduce homelessness.

Homelessness is an economic and social crisis. In a cluster-randomized controlled trial, we address a core cause of homelessness-lack of money-by providing a one-time unconditional cash transfer of CAD$7,500 to each of 50 individuals experiencing homelessness, with another 65 as controls in Vancouver, BC. Exploratory analyses showed that over 1 y, cash recipients spent fewer days homeless, increased savings and spending with no increase in temptation goods spending, and generated societal net savings of $777 per recipient via reduced time in shelters. Additional experiments revealed public mistrust toward the ability of homeless individuals to manage money and demonstrated interventions to increase public support for a cash transfer policy using counter-stereotypical or utilitarian messaging. Together, this research offers a new approach to address homelessness and provides insights into homelessness reduction policies.

Response to von Schmalensee et al.

Von Schmalensee et al. present two concerns about our study. While the first stems from a general disagreement about our simulation methodology, the second is a useful observation of a modelling choice we made that affected simulation outcomes, but in ways that do not invalidate our original conclusions.

A novel, high-performance, low-volume, rapid luciferase immunoprecipitation system (LIPS) assay to detect autoantibodies to zinc transporter 8.

BACKGROUND: Zinc transporter 8 autoantibodies (ZnT8A) are thought to appear close to type 1 diabetes (T1D) onset and can identify high-risk multiple (≥2) autoantibody positive individuals. Radiobinding assays (RBA) are widely used for ZnT8A measurement but have limited sustainability. We sought to develop a novel, high-performance, non-radioactive luciferase immunoprecipitation system (LIPS) assay to replace RBA. METHODS: A custom dual C-terminal ZnT8 (aa268-369; R325/W325) heterodimeric antigen, tagged with a NanoluciferaseTM (Nluc-ZnT8) reporter, and LIPS assay was developed. Assay performance was evaluated by testing sera from new onset T1D (n = 573), healthy schoolchildren (n = 521), and selected first-degree relatives (FDRs) from the Bart's Oxford family study (n = 617; 164 progressed to diabetes). RESULTS: In new-onset T1D, ZnT8A levels by LIPS strongly correlated with RBA (Spearman's r = 0.89; P < 0.0001), and positivity was highly concordant (94.3%). At a high specificity (95%), LIPS and RBA had comparable assay performance [LIPS pROC-AUC(95) 0.032 (95% CI: 0.029-0.036); RBA pROC-AUC(95) 0.031 (95% CI: 0.028-0.034); P = 0.376]. Overall, FDRs found positive by LIPS or RBA had a comparable 20-year diabetes risk (52.6% and 59.7%, respectively), but LIPS positivity further stratified T1D risk in FDRs positive for at least one other islet autoantibody detected by RBA (P = 0.0346). CONCLUSION: This novel, high-performance, cheaper, quicker, higher throughput, low blood volume Nluc-ZnT8 LIPS assay is a safe, non-radioactive alternative to RBA with enhanced sensitivity and ability to discriminate T1D progressors. This method offers an advanced approach to current strategies to screen the general population for T1D risk for immunotherapy trials and to reduce rates of diabetic ketoacidosis at diagnosis.

An observational study to understand burden and cost of care in adults diagnosed with refractory chronic cough (RCC) or unexplained chronic cough (UCC).

BACKGROUND: Refractory and unexplained chronic cough (RCC and UCC) necessitate frequent referral for specialist evaluations, but data on healthcare resource utilisation and costs are lacking. METHODS: This observational study enrolled adults with RCC or UCC attending a specialist cough clinic and included a control cohort, both from North West England, matched 1:5 for age, gender and smoking history. Primary and secondary care data were obtained for the 5 years prior to and 2 years post initial clinic visit (index). The primary endpoint was the total 5-year healthcare cost to the UK NHS pre-RCC or UCC diagnosis compared to the control cohort. RESULTS: Mean age at index for the 200 RCC or UCC consented patients was 62.2 ± 11.4 years; 71% were female, and 68% had never smoked. Mean duration of symptoms pre-diagnosis was 8.0 ± 9.4 years. Mean cough severity score was 63.7 ± 23.2 mm at index on a Visual Analog Scale, and Leicester Cough Questionnaire total score was 10.9 ± 4.1. GP data were available for 80 patients and mean total cost over the 5 years pre-diagnosis (index date) was 3.0-fold higher (95% CI 2.3, 3.9) than in the control cohort (p < 0.001). Most excess costs were related to visits and procedures carried out in secondary care. RCC- or UCC-associated costs decreased post-diagnosis, but remained higher than those of controls. CONCLUSION: Diagnosis of RCC or UCC requires significant health resource utilisation in the 5 years prior to a specialist clinic diagnosis. Resource utilisation was less after diagnosis, but remained higher than in a matched control cohort.

Islet autoantibody frequency in relatives of children with type 1 diabetes who have a type 2 diabetes diagnosis.

AIM: This study aimed to evaluate characteristics of autoimmunity in individuals who have a type 2 diagnosis and are relatives of children with type 1 diabetes. METHODS: Pre-diagnosis samples (median 17 months before onset) from relatives who were later diagnosed with type 2 diabetes were measured for autoantibodies to glutamate decarboxylase 65 (GADA), islet antigen-2 (IA-2A), zinc transporter 8 (ZnT8A) and insulin (IAA) as well as the type 1 diabetes genetic risk score (GRS2). Associations between islet autoantibodies, insulin treatment and GRS2 were analysed using Fisher's exact and t-tests. RESULTS: Among 226 relatives (64% men; mean age at sampling 41 years; mean age 54 years at diagnosis), 32 (14%) were islet autoantibody-positive for at least one autoantibody more than a decade before diagnosis. Approximately half of these (n = 15) were treated with insulin. GADA-positivity was higher in insulin-treated relatives than in non-insulin-treated relatives (12/18 [67%] vs. 6/18 [33%], p < 0.001). IAA-positivity was observed in 13/32 (41%) of relatives with autoantibodies. GRS2 scores were increased in autoantibody-positive relatives (p = 0.032), but there was no clear evidence for a difference according to treatment (p = 0.072). CONCLUSION: This study highlights the importance of measuring islet autoantibodies, including IAA, in relatives of people with type 1 diabetes to avoid misdiagnosis.

A biphasic response to blueberry supplementation on depressive symptoms in emerging adults: a double-blind randomized controlled trial.

PURPOSE: The aim of the present study was to examine the acute and chronic effects of wild blueberry supplementation on mood, executive function, and serum biomarkers of neuroplasticity, inflammation, and oxidative stress in emerging adults with moderate-to-severe depressive symptoms. METHODS: In this double-blind trial, 60 emerging adults (Mage = 20.0 years, 32% male) with self-reported depressive symptoms were randomly assigned to receive a single blueberry drink (acute phase), followed by 6 weeks of daily blueberry supplementation (chronic phase), or a matched placebo drink. The primary outcome was Beck Depression Inventory-II (BDI-II) scores at 6-week follow-up. Further measures included momentary affect (PANAS-X) and accuracy on an executive function task. The data were analyzed using ANCOVAs adjusted for baseline values, sex, and habitual fruit and vegetable intake. Estimated marginal means were calculated to compare the treatment arms. RESULTS: The blueberry drink significantly improved positive affect (p = 0.026) and executive function (p = 0.025) at 2 h post-ingestion, with change scores being positively correlated in the blueberry group (r = 0.424, p = 0.017). However, after six weeks of supplementation the reduction in BDI-II scores was greater in the placebo group by 5.8 points (95% CI: 0.8-10.7, p = 0.023). Generalized anxiety and anhedonia also decreased significantly more in the placebo group. No significant differences were found for any of the biomarkers. CONCLUSIONS: Six weeks of wild blueberry supplementation were inferior to placebo in reducing depressive symptoms. Nevertheless, the correlated improvements in positive affect and executive function after a single dose of blueberries point to a beneficial, albeit transient, psychological effect. These contrasting results suggest a biphasic, hormetic-like response that warrants further investigation. TRIAL REGISTRATION: NCT04647019, dated 30 November, 2020.

Caffeine gum improves 5 km running performance in recreational runners completing parkrun events.

PURPOSE: The purpose of this study was to determine whether caffeine gum improves the performance of recreational runners completing parkruns (weekly, 5 km, mass participant running events). METHODS: Thirty-six recreational runners (M = 31, F = 5; age 33.7 ± 10.7 y; BMI 23.1 ± 2.4 kg/m2) capable of running 5 km in < 25 min were recruited to a study at the Sheffield Hallam parkrun, UK. Runners were block randomized into one of three double-blind, placebo-controlled, cross-over intervention trials with caffeine gum as the treatment (n = 6 per intervention trial) or into one of three non-intervention trials that ran concurrently with the intervention trials (n = 6 per non-intervention trial). Changes in conditions across different parkruns were adjusted for using data from the non-intervention trials. Runners in the randomized cross-over intervention trials chewed gum supplying 300 mg of caffeine or a placebo gum for 5 min, starting 30 min before each parkrun. RESULTS: Caffeine gum improved 5 km parkrun performance by a mean of 17.28 s (95% CI 4.19, 30.37; P = 0.01). Adjustment for environmental conditions using data from the non-intervention trials attenuated the statistical significance (P = 0.04). Caffeine gum also decreased RPE by 1.21 (95% CI 0.30, 2.13; P = 0·01) units relative to placebo. CONCLUSIONS: A 300 mg dose of caffeine supplied in chewing gum improved the performance of recreational runners completing 5 km parkruns by an average of 17 s. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov: NCT02473575 before recruitment commenced.

Commentary: The microbial dependence continuum: Towards a comparative physiology approach to understand host reliance on microbes.

Comparative physiologists often compare physiological traits across organisms to understand the selective pressures influencing their evolution in different environments. Traditionally focused on the organisms themselves, comparative physiology has more recently incorporated studies of the microbiome-the communities of microbes living in and on animals that influence host physiology. In this commentary, we describe the utility of applying a comparative framework to study the microbiome, particularly in understanding how hosts vary in their dependence on microbial communities for physiological function, a concept we term the "microbial dependence continuum". This hypothesis suggests that hosts exist on a spectrum ranging from high to low reliance on their microbiota. Certain physiological traits may be highly dependent on microbes for proper function in some species but microbially independent in others. Comparative physiology can elucidate the selective pressures driving species along this continuum. Here, we discuss the microbial dependence continuum in detail and how comparative physiology can be useful to study it. Then, we discuss two example traits, herbivory and flight, where comparative physiology has helped reveal the selective pressures influencing host dependence on microbial communities. Lastly, we discuss useful experimental approaches for studying the microbial dependence continuum in a comparative physiology context.

A comprehensive investigation of the association between menopause symptoms and problematic eating behavior in peri- and post-menopause cisgender women.

Midlife individuals assigned female at birth are at risk for problematic eating behavior, associated with negative health outcomes. Little is known about how menopausal symptoms may increase risk in this population. The current study aimed to understand how a comprehensive range of menopause symptoms were globally associated with problematic eating behaviors. A total of 281 cisgender women (176 post-menopause, 105 peri-menopause) from the United States aged 40 to 64 were recruited utilizing Prolific, an online survey platform. Participants answered questionnaires about menopause symptoms and problematic eating. Participants were selected using demographic and health information provided in a screener survey. Participants also completed the Eating Disorder Questionnaire (EDE-Q), Women's Health Questionnaire (WHQ), Patient Health Questionnaire-8 (PHQ-8), Generalized Anxiety Disorder-7 (GAD-7), and Pittsburgh Sleep Quality Index (PSQI). Using Structural Equation Modeling, menopause symptoms explained 16.7 percent of the variance in problematic eating. Higher frequency and severity of anxiety, depression, sleep concerns, cognitive complaints, pain, and vasomotor symptoms was associated with greater frequency and severity of problematic eating behaviors, ß = .40, p < .001. Invariance testing showed no significant differences between peri- and postmenopausal women. These findings support the association between menopause symptoms and problematic eating in Midlife cisgender women and highlight the need for continued investigation.

The Chartered Institute of Ergonomics and Human Factors at 75: perspectives on contemporary challenges and future directions for Ergonomics and Human Factors.

As the UK's Chartered Institute of Ergonomics and Human Factors (CIEHF) celebrates its 75th anniversary, it is worth reflecting on our discipline's contribution, current state, and critical future endeavours. We present the perspectives of 18 EHF professionals who were asked to respond to five questions regarding the impact of EHF, contemporary challenges, and future directions. Co-authors were in agreement that EHF's impact has been only limited to date and that critical issues require resolution, such as increasing the number of suitably qualified practitioners, resolving the research-practice gap, and increasing awareness of EHF and its benefits. Frequently discussed future directions include advanced emerging technologies such as artificial intelligence, the development of new EHF methods, and enhancing the quality and reach of education and training. The majority felt there will be a need for EHF in 75 years; however, many noted that our methods will need to adapt to meet new needs.Practitioner statement: This article provides the perspectives of 18 Ergonomics and Human Factors (EHF) professionals on the impact of EHF, contemporary challenges and critical future directions, and changes that are necessary to ensure EHF remains relevant in future. As such, it provides important guidance on future EHF research and practice.

Evolutionary constraints mediate extinction risk under climate change.

Mounting evidence suggests that rapid evolutionary adaptation may rescue some organisms from the impacts of climate change. However, evolutionary constraints might hinder this process, especially when different aspects of environmental change generate antagonistic selection on genetically correlated traits. Here, we use individual-based simulations to explore how genetic correlations underlying the thermal physiology of ectotherms might influence their responses to the two major components of climate change-increases in mean temperature and thermal variability. We found that genetic correlations can influence population dynamics under climate change, with declines in population size varying three-fold depending on the type of correlation present. Surprisingly, populations whose thermal performance curves were constrained by genetic correlations often declined less rapidly than unconstrained populations. Our results suggest that accurate forecasts of the impact of climate change on ectotherms will require an understanding of the genetic architecture of the traits under selection.

Active learning narrows achievement gaps for underrepresented students in undergraduate science, technology, engineering, and math.

We tested the hypothesis that underrepresented students in active-learning classrooms experience narrower achievement gaps than underrepresented students in traditional lecturing classrooms, averaged across all science, technology, engineering, and mathematics (STEM) fields and courses. We conducted a comprehensive search for both published and unpublished studies that compared the performance of underrepresented students to their overrepresented classmates in active-learning and traditional-lecturing treatments. This search resulted in data on student examination scores from 15 studies (9,238 total students) and data on student failure rates from 26 studies (44,606 total students). Bayesian regression analyses showed that on average, active learning reduced achievement gaps in examination scores by 33% and narrowed gaps in passing rates by 45%. The reported proportion of time that students spend on in-class activities was important, as only classes that implemented high-intensity active learning narrowed achievement gaps. Sensitivity analyses showed that the conclusions are robust to sampling bias and other issues. To explain the extensive variation in efficacy observed among studies, we propose the heads-and-hearts hypothesis, which holds that meaningful reductions in achievement gaps only occur when course designs combine deliberate practice with inclusive teaching. Our results support calls to replace traditional lecturing with evidence-based, active-learning course designs across the STEM disciplines and suggest that innovations in instructional strategies can increase equity in higher education.

The SLC36 transporter Pathetic is required for extreme dendrite growth in Drosophila sensory neurons.

Dendrites exhibit enormous diversity in form and can differ in size by several orders of magnitude even in a single animal. However, whether neurons with large dendrite arbors have specialized mechanisms to support their growth demands is unknown. To address this question, we conducted a genetic screen for mutations that differentially affected growth in neurons with different-sized dendrite arbors. From this screen, we identified a mutant that selectively affects dendrite growth in neurons with large dendrite arbors without affecting dendrite growth in neurons with small dendrite arbors or the animal overall. This mutant disrupts a putative amino acid transporter, Pathetic (Path), that localizes to the cell surface and endolysosomal compartments in neurons. Although Path is broadly expressed in neurons and nonneuronal cells, mutation of path impinges on nutrient responses and protein homeostasis specifically in neurons with large dendrite arbors but not in other cells. Altogether, our results demonstrate that specialized molecular mechanisms exist to support growth demands in neurons with large dendrite arbors and define Path as a founding member of this growth program.

Changing particle content of the modern desert dust storm: a climate × health problem.

Climate and land use changes together are altering the particle content of desert dust storms on regional and local scales. These storms now carry a wide variety of pollutants and pathogens arising from urbanization, industrialization, mass transportation, warfare, or aerosolized waste in locations worldwide where deserts are intertwined with built infrastructure, transportation centers, and high-density human habitation. Accordingly, the modern desert dust storm has an anthropogenic particle load which presumably sets it apart from pre-industrial dust storms. Evidence for how particle content for modern dust storms is changing over the Arabian Peninsula holds relevance because dust storms are now more frequent and more severe. Furthermore, the Arabian Peninsula has asthma rates which are the highest worldwide. How the modern desert dust storm contributes to asthma and human health is a nascent issue. Meanwhile, public health decisions can benefit from a climate × health framework for dust storms, as proposed here. An imperative is testing each dust storm's particle content type, and for this, we propose the A-B-C-X model. Sampling a dust storm for its particle content data and then archiving samples for future analyses is advised. A storm's particle content data, once combined with its atmospheric data, allows a particle's source, transport, and deposition to be determined. In closing, the modern desert dust storm's changing particle content has far-reaching consequences for public health, transboundary issues, and international climate dialog. SIGNIFICANCE : Locally and regionally sourced particle pollution is a growing problem in deserts worldwide. Proposed here is a climate × health framework for studying how dust storm particles, entrained from both natural and engineered systems, may be contributing to declining human respiratory health.

Morphogenesis of neurons and glia within an epithelium.

To sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the C. elegans amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM. Here, we show that amphid neurons and glia exhibit epithelial properties, including tight junctions and apical-basal polarity, and develop in a manner resembling other epithelia. We find that DYF-7 is a fibril-forming apical ECM component that promotes formation of the tube-shaped glial channel, reminiscent of roles for apical ECM in other narrow epithelial tubes. We also identify a requirement for FRM-2, a homolog of EPBL15/moe/Yurt that promotes epithelial integrity in other systems. Finally, we show that other environmentally exposed neurons share a requirement for DYF-7. Together, our results suggest that these neurons and glia can be viewed as part of an epithelium continuous with the skin, and are shaped by mechanisms shared with other epithelia.

Sustained Drought, but Not Short-Term Warming, Alters the Gut Microbiomes of Wild Anolis Lizards.

As rising temperatures threaten biodiversity across the globe, tropical ectotherms are thought to be particularly vulnerable due to their narrow thermal tolerance ranges. Nevertheless, physiology-based models highlighting the vulnerability of tropical organisms rarely consider the contributions of their gut microbiota, even though microbiomes influence numerous host traits, including thermal tolerance. We combined field and lab experiments to understand the response of the slender anole lizard (Anolis apletophallus) gut microbiome to climatic shifts of various magnitude and duration. First, to examine the effects of long-term climate warming in the wild, we transplanted lizards from the mainland Panama to a series of warmer islands in the Panama Canal and compared their gut microbiome compositions after three generations of divergence. Next, we mimicked the effects of a short-term "heat-wave" by using a greenhouse experiment and explored the link between gut microbiome composition and lizard thermal physiology. Finally, we examined variation in gut microbiomes in our mainland population in the years both before and after a naturally occurring drought. Our results suggest that slender anole microbiomes are surprisingly resilient to short-term warming. However, both the taxonomic and predicted functional compositions of the gut microbiome varied by sampling year across all sites, suggesting that the drought may have had a regional effect. We provide evidence that short-term heat waves may not substantially affect the gut microbiota, while more sustained climate anomalies may have effects at broad geographic scales. IMPORTANCE As climate change progresses, it is crucial to understand how animals will respond to shifts in their local environments. One component of this response involves changes in the microbial communities living in and on host organisms. These "microbiomes" can affect many processes that contribute to host health and survival, yet few studies have measured changes in the microbiomes of wild organisms experiencing novel climatic conditions. We examined the effects of shifting climates on the gut microbiome of the slender anole lizard (Anolis apletophallus) by using a combination of field and laboratory studies, including transplants to warm islands in the Panama Canal. We found that slender anole microbiomes remain stable in response to short-term warming but may be sensitive to sustained climate anomalies, such as droughts. We discuss the significance of these findings for a species that is considered highly vulnerable to climate change.

Role of the Microbiome in Regulating Bone Metabolism and Susceptibility to Osteoporosis.

The human microbiota functions at the interface between diet, medication-use, lifestyle, host immune development and health. It is therefore closely aligned with many of the recognised modifiable factors that influence bone mass accrual in the young, and bone maintenance and skeletal decline in older populations. While understanding of the relationship between micro-organisms and bone health is still in its infancy, two decades of broader microbiome research and discovery supports a role of the human gut microbiome in the regulation of bone metabolism and pathogenesis of osteoporosis as well as its prevention and treatment. Pre-clinical research has demonstrated biological interactions between the microbiome and bone metabolism. Furthermore, observational studies and randomized clinical trials have indicated that therapeutic manipulation of the microbiota by oral administration of probiotics may influence bone turnover and prevent bone loss in humans. In this paper, we summarize the content, discussion and conclusions of a workshop held by the Osteoporosis and Bone Research Academy of the Royal Osteoporosis Society in October, 2020. We provide a detailed review of the literature examining the relationship between the microbiota and bone health in animal models and in humans, as well as formulating the agenda for key research priorities required to advance this field. We also underscore the potential pitfalls in this research field that should be avoided and provide methodological recommendations to facilitate bridging the gap from promising concept to a potential cause and intervention target for osteoporosis.

The measurement of autoantibodies to insulin informs diagnosis of diabetes in a childhood population negative for other autoantibodies.

AIMS: Some childhood type 1 diabetes cases are islet autoantibody negative at diagnosis. Potential explanations include misdiagnosis of genetic forms of diabetes or insufficient islet autoantibody testing. Many NHS laboratories offer combinations of three autoantibody markers. We sought to determine the benefit of testing for additional islet autoantibodies, including insulin (IAA) and tetraspanin 7 (TSPAN7A). METHODS: Radiobinding assays (RBAs) were used to test for four islet autoantibodies in children with newly diagnosed type 1 diabetes (n = 486; 54.1% male; median age 10.4 years [range 0.7-18.0]; median duration 1 day [range -183 to 14]). Islet autoantibody negative children were tested for TSPAN7A using a luminescence-based test. Where available, islet cell antibody (ICA) and human leucocyte antigen (HLA) data were considered. RESULTS: Using three autoantibody markers, 21/486 (4.3%) children were autoantibody negative. Testing for IAA classified a further 9/21 (42.9%) children as autoantibody positive. Of the remaining 12 (2.5%) autoantibody negative children, all were TPAN7A negative, seven were ICA negative and one was positive for the protective variant DQB1*0602. One was subsequently diagnosed with Maturity Onset of Diabetes in the Young, but follow-up was not available in all cases. CONCLUSIONS: Using highly sensitive assays, testing for three autoantibodies fails to detect islet autoimmunity in approximately 1/20 children diagnosed with type 1 diabetes. Testing for IAA in children <5 years and GADA in those >10 years was the most effective strategy for detecting islet autoimmunity. The ability to test for all islet autoantibodies should inform clinical decisions and make screening for monogenic diabetes more cost-effective.

Estimating and Extrapolating Survival Using a State-Transition Modeling Approach: A Practical Application in Multiple Myeloma.

OBJECTIVES: State-transition models (STMs) applied in oncology have given limited considerations to modeling postprogression survival data. This study presents an application of an STM focusing on methods to evaluate the postprogression transition and its impact on survival predictions. METHODS: Data from the lenalidomide plus dexamethasone arm of the ASPIRE trial was used to estimate transition rates for an STM. The model accounted for the competing risk between the progression and preprogression death events and included an explicit structural link between the time to progression and subsequent death. The modeled transition rates were used to simulate individual disease trajectories in a discrete event simulation framework, based on which progression-free survival and overall survival over a 30-year time horizon were estimated. Survival predictions were compared with the observed trial data, matched external data, and estimates obtained from a more conventional partitioned survival analysis approach. RESULTS: The rates of progression and preprogression death were modeled using piecewise exponential functions. The rate of postprogression mortality was modeled using an exponential function accounting for the nonlinear effect of the time to progression. The STM provided survival estimates that closely fitted the trial data and gave more plausible long-term survival predictions than the best-fitting Weibull model applied in a partitioned survival analysis. CONCLUSIONS: The fit of the STM suggested that the modeled transition rates accurately captured the underlying disease process over the modeled time horizon. The considerations of this study may apply to other settings and facilitate a wider use of STMs in oncology.

Vitamin D supplementation in people with IBS has no effect on symptom severity and quality of life: results of a randomised controlled trial.

PURPOSE: Several small trials suggest a benefit of vitamin D supplementation in irritable bowel syndrome (IBS). The generalisability of these reports is limited by their design and scale. This study aimed to assess whether vitamin D supplementation improved IBS symptoms in a UK community setting. METHODS: This was a randomised, double-blind, placebo-controlled study. Participants were recruited from the community in winter months between December 2017 and March 2019. 135 participants received either vitamin D (3,000 IU p.d.) or placebo for 12 weeks. The primary outcome measure was change in IBS symptom severity; secondary outcomes included change in IBS-related quality of life. RESULTS: The participants were analysed on an intent-to-treat basis. 60% of participants were vitamin D deficient or insufficient at baseline. Although vitamin D levels increased in the intervention arm relative to placebo (45.1 ± 32.88 nmol/L vs 3.1 ± 26.15 nmol/L; p < 0.001). There was no difference in the change of IBS symptom severity between the active and placebo trial arms (- 62.5 ± 91.57 vs - 75.2 ± 84.35, p = 0.426) over time. Similarly there was no difference between trial arms in τhe change in quality of life (- 7.7 ± 25.36 vs - 11.31 ± 25.02, p = 0.427). CONCLUSIONS: There is no case for advocating use of vitamin D in the management of IBS symptoms. The prevalence of vitamin D insufficiency suggests routine screening and supplementation should be implemented in this population for general health reasons. This trial was retrospectively registered with ISRCTN (ISRCTN13277340) on 24th April 2018 after recruiting had been initiated.