The purpose of the present article is to describe the current state of sex and gender data collection in nutrition science research, discuss the effects of flawed data collection practices, highlight considerations for transgender and gender non-conforming populations and propose a sex- and gender-informed approach to human subjects research. Sex and gender are separate constructs that are often conflated in nutrition research and practice. Current nutrition surveillance programmes in the United States, United Kingdom and Ireland do not accurately capture sex and gender data, which undermines the accuracy of the analyses and excludes gender minorities. Transgender and gender non-conforming populations have distinct clinical and psychosocial nutrition considerations that require further research to inform nutrition policy and practice, such as anthropometric and biochemical changes with hormone therapy, eating disorders, food insecurity and nutrition as a source of empowerment or expression of gender identity. Researchers can apply a sex- and gender-informed approach to human subjects research by treating sex and gender as separate, relevant demographic data, appreciating gender as a fluid construct, and approaching data collection on gender minorities with sensitivity to privacy and confidentiality.

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) improves functional bowel symptoms and is a second-line dietary management strategy for the treatment of irritable bowel syndrome (IBS). The diet is complex and involves three stages: restriction, reintroduction and personalisation and clinical effectiveness is achieved with dietitian-led education; however, this is not always available. The aim of this review is to provide an update on the evidence for using the low FODMAP diet, with a focus on the impact of FODMAP restriction and reintroduction considering long-term management of IBS in a clinical setting. Randomised controlled trials have assessed symptom response, quality of life, dietary intake and changes to the gut microbiota during FODMAP restriction. Systematic reviews and meta-analyses consistently report that FODMAP restriction has a better symptom response compared with control diets and a network analysis reports the low FODMAP diet is superior to other dietary treatments for IBS. Research focused on FODMAP reintroduction and personalisation is limited and of lower quality, however common dietary triggers include wheat, onion, garlic, pulses and milk. Dietitian-led delivery of the low FODMAP diet is not always available and alternative education delivery methods, e.g. webinars, apps and leaflets, are available but remove the personalised approach and may be less acceptable to patients and may introduce safety concerns in terms of nutritional adequacy. Predicting response to the low FODMAP diet using symptom severity or a biomarker is of great interest. More evidence on less restrictive approaches and non-dietitian-led education delivery methods are needed.

A range of metrics have been developed and used to measure components of dietary patterns (e.g., adequacy, quality, diversity). However, no existing dietary metric simultaneously captures the three key dimensions of sustainable healthy diets recommended by the Food and Agriculture Organization of the United Nations and the World Health Organization: food processing; dietary diversity; and intake of animal products(1). This study aimed to identify indicators of a global sustainable healthy diet and translate these features into a multidimensional diet quality score (SUSDIET). Informed by our scoping review(1), a Delphi method was adopted in the form of a three-round online survey of 13 national and international experts in nutritional epidemiology, environmental health, dietary assessment and/or food and nutrition policy. Surveys were conducted between November 2022 and May 2023. Participants were asked about procedures to establish an operational definition for a global sustainable healthy diet. Based on consensus from global experts, we developed the SUSDIET, a food-based diet quality score incorporating variety of plant foods, intake of animal products, and dietary contribution of ultra-processed foods (the ‘dimensions’). Categories and amounts of foods consumed were informed by the Global Diet Quality Score(2), EAT Lancet Planetary Health(3) and a meta-analysis of the relationship between ultra-processed foods and all-cause mortality(4). The variety of plant foods is measured based on 12 food groups (citrus fruits, deep orange fruits, other fruits, dark green leafy vegetables, cruciferous vegetables, deep orange vegetables, other vegetables, legumes, deep orange tubers, nuts and seeds, whole grains, white roots and tubers), animal intake based on 5 food groups (egg, dairy, poultry, fish and seafood, red meat), and ultra-processed foods as one food group. Three categories of consumed amounts (in grams per day) are defined for variety of plant foods and animal intake, scoring as 0, 0.5 or 1. Ultra-processed food consumption is scored as 0 or 1 using ≤10% or >10% of total dietary intake as cut-offs. The components of each dimension are weighted so the three dimensions equally range from 0-5. SUSDIET overall score ranges from 0-15 (up to 5 points per dimension), with a higher score indicating a more healthy and sustainable diet. SUSDIET will be of immediate use for research aiming to assess the impact of diets on both health and environmental sustainability outcomes among the general adult population. This multidimensional diet quality score can also be used to inform and assess the effectiveness of policy actions that promote sustainable healthy diets, including the monitoring and surveillance of diets globally.

This abstract was presented as the Nutrition and Optimum Life Course Theme Highlight.

The n-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), are known for their beneficial roles in regulating inflammation(1). The omega 3 index (O3I) refers to the percentage of EPA+DHA within the erythrocyte membrane with respect to total fatty acids and is a recognised biomarker for cardiovascular disease(2). An O3I >8% is proposed to confer the greatest level of cardioprotection(2). Fish is the richest dietary source of n-3 PUFAs and has been noted as one of the main predictors of a higher O3I(3). Current UK dietary guidelines recommend the consumption of two portions of fish per week; albeit the efficacy of these recommendations in raising the O3I is unknown(4). The aim of this study was to investigate the influence of consuming two portions of fish per week on the O3I amongst low fish consuming women of childbearing age.

Data were analysed from the iFish study(5), an 8-week randomised controlled trial where low fish consuming women, were randomly assigned to consume either no fish (n = 18) or 2 portions of tuna (n = 8) or sardines (n = 9) per week. Total n-3 PUFA concentrations of the fish provided in the intervention were 6.47g/100g for sardines and 4.57g/100g for tuna. Fasting blood samples were collected at baseline and post-intervention. The O3I was determined in red blood cells in the control and two portions of fish groups by OmegaQuant Europe. Analysis of covariance, adjusting for age, BMI, and baseline O3I, examined the effect of the fish intervention on the O3I. Chi-square test was used to compare the O3I between groups when categorised as at risk (<4%), intermediate risk (48%) and low risk (>8%).

Participants had a mean ± SD age of 25.5 ± 6.4 years. Baseline median (IQR) O3I of the cohort was 5.7 (5.2, 6.7) %. There was no significant difference in the O3I between treatment groups at baseline. Consumption of two portions of fish significantly increased the O3I when compared to the consumption of no fish [6.73 (5.41, 7.38) % vs 5.58 (5.12, 6.49) %, respectively, p = 0.034]. Those consuming two portions of sardines, an oily fish high in n-3 PUFAs, had a significantly greater O3I when compared to those consuming two portions of tuna [7.38 (6.83, 8.37) % vs 5.61 (5.29, 6.79) %, respectively, p<0.001]. Post-intervention, the proportion of participants in the low risk O3I category (>8%) was greater in the two portions of fish group when compared to the control group; albeit this did not reach statistical significance (p = 0.104).

In support of the current dietary guidelines, increasing fish consumption of low consumers to two portions of any fish per week will increase the O3I. Future research should determine the potential cardioprotective properties of a higher O3I as a result of consuming fish.

The circadian timing system regulates many aspects of metabolic physiology, including the postprandial response to meals(1). Experimental inversion of circadian and behavioural rhythms by 12 hours adversely effects markers of metabolic health(2). We investigated effects of a more modest 5hour delay in behavioural cycles.

Fourteen participants completed an 8-day in-patient laboratory protocol, with controlled sleepwake opportunities, light-dark cycles, and diet. The 5-hour delay in behavioural cycles was induced by delaying sleep opportunity. We measured: melatonin to confirm central circadian phase; fasting markers and postprandial metabolism; energy expenditure; subjective sleepiness; and appetite, throughout the waking period.

After the phase delay, there was slower gastric emptying at breakfast, lower fasting plasma glucose, higher postprandial plasma glucose and triglycerides, and lower thermic effect of feeding. Any changes were abolished or attenuated within 48-72 hours. Further, we show no difference in 16 h waking energy expenditure.

These data extend our previous findings, which showed no time-of-day effect on energy expenditure in healthy adults.

The aim of this review is to highlight the key issues in relation to food insecurity among children and young people living in Scotland. It provides an overview of the current context of food insecurity more generally within the UK and specifically in Scotland. Food insecurity has risen in Scotland evidenced through responses to national surveys and the dramatic increase in households relying on emergency food provision. Food insecurity is highest among young people, single parent families and single men. The key drivers of food insecurity include insufficient income, welfare reform, food inflation and geo-political events. Evidence suggests that food insecurity is negatively related to sufficient nutritional intake, and the implications for physical and mental health are profound. Policy actions implemented to mitigate the impact of food insecurity on children and young people include the introduction of the Scottish Child Payment, food voucher schemes, free school meals, and holiday food provision. Further evidence is required to evaluate the success of these policies in reducing or mitigating food insecurity. The review concludes by considering the ways in which a rights-based approach to food might benefit children and young people living in Scotland, and argues that wider systemic change is required.

The teenage years represent a crucial period of physical and cognitive growth and development with sufficient micronutrient intakes necessary to meet high nutritional requirements. This review examines current micronutrient intakes in teenagers in the Western world in the context of public health implications including the prevalence of inadequate intakes and risk of excessive intakes. Intakes of vitamins A, D, E and C, folate, calcium, iron, magnesium, zinc and potassium in teenagers are low when compared to generally accepted recommendations, while there is little risk of excessive micronutrient intakes based on current dietary patterns. Therefore, strategies should focus on increasing micronutrient intakes in order to decrease the risk of negative impacts resulting from these low intakes. These strategies should be mindful of guidance towards an environmentally sustainable diet whilst ensuring that nutrient intakes in teenagers are not further negatively impacted. In order to identify, implement and monitor the effectiveness of such strategies, intakes of micronutrients should be continually monitored in nationally representative samples of the population for all age groups including this vulnerable cohort of teenagers.

The trace element selenium is known to protect against oxidative damage which is known to contribute to cognitive impairment with ageing (1,2). The aim of this study was to explore the association between selenium status (serum selenium and selenoprotein P (SELENOP)) and global cognitive performance at baseline and after 5 years in 85-year-olds living in the Northeast of England.

Serum selenium and SELENOP concentrations were measured at baseline by total reflection X-ray fluorescence (TXRF) and enzyme-linked immunosorbent assay (ELISA), respectively, in 757 participants from the Newcastle 85+ study. Global cognitive performance was assessed using the Standardized Mini-Mental State Examination (SMMSE) where scores ≤25 out of 30 indicated cognitive impairment. Logistic regressions explored the associations between selenium status and global cognition at baseline. Linear mixed models explored associations between selenium status and global cognition prospectively after 5 years. Covariates included sex, body mass index, physical activity, high sensitivity C-reactive protein, alcohol intake, self-rated health, medications and smoking status.

At baseline, in fully adjusted models, there was no increase in odds of cognitive impairment with serum selenium (OR 1.004, 95% CI 0.993-1.015, p = 0.512) or between SELENOP (OR 1.006, 95% CI 0.881-1.149, p = 0.930). Likewise, over 5 years, in fully adjusted models there was no association between serum selenium and cognitive impairment (β 7.20E-4 ± 5.57E-4, p = 0.197), or between SELENOP and cognitive impairment (β 3.50E-3 ± 6.85E-3, p = 0.610).

In this UK cohort of very old adults, serum selenium or SELENOP was not associated with cognitive impairment at baseline and 5 years. This was an unexpected finding despite SELENOP’s key role in the brain and the observed associations in other studies. Further research is needed to explore the effect of selenium on global cognition in very old adults.

Malnutrition affects over half the world’s population, manifesting in myriad forms. Nearly 1 in 4 children never reach their full growth potential, while 1 in 2 lack key micronutrients essential for health and development.1 Furthermore, 1 in 3 women suffer from anemia, and 2 in 3 do not get enough vital micronutrients. At the same time, over 2 in 5 adults are overweight or obese, and 1 in 5 live with high blood pressure. These various forms of malnutrition lead to physical and cognitive impairments, increased susceptibility to infections and chronic diseases, and reduced quality and length of life. They also impose immense economic, social, and health burdens. In addition to harming human health, our food system damages the planet, generating greenhouse gas emissions that drive climate change and depleting freshwater reserves. It also causes deforestation and habitat destruction which drive species to extinction. These grave harms to both human and environmental wellbeing demand urgent action. Transforming our food systems is imperative to promote nutritious diets that deliver adequate nutrition and protect against noncommunicable diseases, while simultaneously protecting our planet, its biodiversity, and natural resources. As a response, many call for drastically limiting consumption of animal source foods like meat, eggs, and dairy. They argue that these foods jeopardize both human health and environmental sustainability. However, is it possible to meet the nutritional needs of the global population with few animal source foods? What are the full impacts, both positive and negative, of animal source foods on human health and the environment? In this presentation, I will review the latest scientific evidence surrounding these questions. I will examine whether mindfully produced and consumed animal source foods can be part of the solution. Join me to explore these critical issues concerning sustainable nutrition and the role of animal source foods in our food system transformation.

This abstract was presented as the Novel Nutrition Research Methodologies and Technologies

Theme Highlight. Queuosine (Q) is a vital micronutrient crucial for protein translation and cellular function in humans. Deficiencies of Q have been linked to chronic illnesses, such as inflammatory bowel disease, neurodegenerative diseases, and various cancers. Human requirements for this micronutrient have not yet been established. Thus far, there has been no systematic investigation of the human diet to understand typical intakes. It is necessary to measure the levels of Q metabolites in commonly consumed foods to identify the richest dietary sources and determine Q intake. Only then can its role in human health and disease be established.

This study aimed to comprehensively analyse Q distribution in the UK diet by quantifying it in foods, identifying rich sources, and ultimately, enabling the design of dietary intervention studies assessing Q absorption/bioavailability.

Data from the UK National Diet and Nutrition Survey (NDNS 5Y) were processed to identify the most frequently consumed foods in 31 main categories, reflecting the dietary habits of >99.5% of UK consumers. Extraction techniques were developed, including a methanol-based method for extracting free Q metabolites and a specialized approach for isolating tRNA-bound Q metabolites from various food matrices. Quantitative LC-MS/MS (SCIEX 5500+) was utilized to accurately measure queuine (q), Q, Q monophosphates (QMPs), and Q precursor (PreQ1) in food samples. These values were summed to determine Total Q levels. Additionally, four-day food diary data from 93 participants in the Northern Ireland Dietary Assessment Study (NIDAS) were analysed to determine the average daily consumption of Q metabolites in adults. Dairy sources were considered promising, so five commercial probiotic yoghurt brands were compared side-by-side.

Q metabolite levels varied significantly across various food types. Total Q metabolite levels in foods ranged from 0.05ng/g to 80ng/g, with a mean level of 20ng/g. The calculated Q consumption of participants in NIDAS ranged from nil/day in some individuals to 170µg/day in others, with a typical mean intake of 18µg/day. The mean amounts (ng/g) of Total Q metabolites (tRNA-bound + free) measured in food categories were dairy 57.2 ± 9.7, meat 20.1 ± 9.9, poultry 4.9 ± 4, and plant-based milk 15.3 ± 10, fruits 2 ± 1.3, vegetables 5.3 ± 2.8, starchy foods 2.2 ± 0.7. Dairy products emerged as significant sources of Q metabolites based on these findings. Concentrations observed in shortlisted probiotic yoghurts ranged from 32 to 352 ng/g.

This study determined typical Q intakes and is the first to identify Q-rich food sources in the UK diet. The highly Q-enriched probiotic yoghurt products could be used in controlled dietary intervention studies to assess Q absorption/bioavailability and this micronutrient’s role in human health and disease.

The aim of the paper is to review the current evidence on the impact of ‘the timing of energy intake’ on the risk of developing obesity and obesity-related metabolic diseases. The prevalence of obesity is currently increasing worldwide thus becoming a severe health burden for most countries. Indeed, obesity represents a risk factor for several non-communicable diseases such as cancer, type 2 diabetes, dyslipidaemia, CVD and overall mortality. In order to treat obesity, several pharmacological approaches have been developed and are indicated for subjects with obesity with a BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 and obesity-related comorbidities. For severe obesity (BMI ≥ 40 kg/m2), bariatric surgery represents a promising approach. The most common bariatric surgical procedures are represented by the Roux-en-Y gastric bypass, laparoscopic adjustable band, laparoscopic gastric sleeve and biliopancreatic diversion with duodenal switch. Both anti-obesity pharmacological and surgical treatments require change in lifestyle. When a nutritional plan is established, attention is usually paid to macronutrient composition and energy intake, while ‘the time of food’ is not taken into account. Chronotype, which is the attitude of a subject to carry out most of their daily activities in the first (morning chronotype) or second half (evening chronotype) of the day, has been reported to have a role in the pathogenesis of obesity and obesity-related cardiometabolic diseases as well as eating speed. Thus, adopting a physiological timing of energy intake could be an additional strategy to potentiate the current anti-obesity approaches.

The high levels of non-communicable diseases such as CVD and type 2 diabetes mellitus are linked to obesity and poor diet. This continuing emphasis on health in relation to food is proving a powerful driver for the development of cheap but palatable and more functional foods. However, the efficacy of such foods is often hard to prove in human subjects. Thus, a suite of tools has been developed including in silico and in vitro simulations and animal models. Although animal models offer physiologically relevant platforms for research, their use for experimentation is problematic for consumers. Thus, in vitro methods such as Infogest protocols have been developed to provide digestion endpoints or even an indication of the kinetics of digestion. These protocols have been validated for a range of food systems but they still miss the final absorption step. This review discusses the use of such in vitro models and what further steps need to be included to make the bioaccessibility determination more relevant to bioavailability and human health.

New Zealand has committed to a 50% reduction in greenhouse gas emissions (GHGEs) from 2005 levels by 2030. Dietary changes within New Zealand could simultaneously improve population health and contribute towards the nation’s emissions reduction target, as agricultural emissions are estimated to account for half of New Zealand’s GHGEs(1). This research aimed to quantify the GHGEs associated with household purchases of major food groups in New Zealand and identify the sociodemographic characteristics that are associated with per capita household dietary emissions. Household dietary emissions were estimated using the NielsenIQ Homescan(R) consumer panel — a large sample of households within New Zealand who report purchasing data of take-home food and beverages. The sample is nationally representative in terms of broad geographical regions and selected key demographic characteristics. Carbon emission estimates were assigned to 1,908,485 total food and beverage purchases from 1,775 households over one year (2019) using a process-based life cycle assessment (LCA) dataset initially constructed in the United Kingdom (UK) and adapted for New Zealand(2). This LCA dataset contains estimates of greenhouse gas emissions generated over the life cycle of the production of food products from the following stages: farming and processing, transit packaging, consumer packaging, transport, warehouse and distribution, refrigeration, and overheads. Greenhouse gas emissions are expressed in kg of carbon dioxide equivalents per kg of food product over a 100-year time horizon. Total emissions from purchases of major food groups were then estimated. Multiple linear regression was used to examine the relationships between household variables and per capita dietary emissions. Overall purchases of red and processed meat (35%) and dairy products (19%) were responsible for the greatest proportion of emissions. The age group of the primary household shopper as well as household size were predictors of per capita dietary emissions — households with primary shoppers > 65 years had, on average, 33% (95% CI: 20% to 49%) higher per capita dietary emissions, compared to households with primary shoppers 34 years; and every additional household member was associated with, on average, 11% (95% CI: 9% to 13%) lower per capita dietary emissions. We have shown in this large representative sample of New Zealand households that purchases of just two food groups — red and processed meat, and dairy — were responsible for approximately half of dietary greenhouse gas emissions. Larger households had lower per capita dietary greenhouse gas emissions, and older shoppers had relatively higher greenhouse gas emissions. Whilst similar associations have been reported elsewhere more research is needed to confirm these latter findings. With enhanced understanding of the observed association between age of a household’s primary shopper and per capita dietary emissions, interventions may be devised that encourage shoppers to purchase lower-emitting foods, particularly less meat and dairy.

The current food system is unsustainable. It encourages unhealthy food choices, increasing the risk of non-communicable diseases, and has a substantial environmental impact, responsible for around a third of all anthropogenic greenhouse gas emissions. Improving both public and planetary health will require dietary change. To promote this transition, it is crucial to understand how consumers conceptualise healthy and sustainable eating. The aim of this review was to examine how adults from high-income countries interpret healthy and sustainable eating, with a specific focus on Ireland and the UK. As healthy eating and sustainable eating are often conceptualised as distinctive constructs, we explored each of these separately before examining how consumers perceive them together. Most consumers have a reasonable understanding of what constitutes a healthy diet, with many echoing aspects consistent with dietary guidelines. However, consumers perceptions of healthy eating often extend beyond these health-centric recommendations, incorporating concepts such as the pleasure of eating and supporting mental well-being. Sustainable eating, on the other hand, is less well understood. Most consumers overemphasise the importance of eating local, organic food and reducing packaging and underestimate or are unaware of the environmental impact of red meat consumption. These findings provide a clear opportunity to improve public awareness of healthy and sustainable diets. Moreover, they emphasise the need to promote the synergies between healthy and sustainable dietary practices. However, knowledge alone will not be enough to change behaviour. Future interventions should also seek to overcome consumers competing dietary priorities and create system-wide changes.

Poor dietary patterns leading to poorer health and increased health care use have affected people living in disadvantaged economic circumstances in the UK for decades, which many fear will be exacerbated due to the UK's current so-called ‘cost of living crisis’. The voices of experts by experience of those health and social inequalities are not routinely included in health improvement intervention development in relation to obesity prevention policy and programmes. Obesity is highly correlated with food insecurity experience in high-income country contexts (where food insecurity data are routinely collected) and is similarly socially patterned. Using a health equity lens, this review paper highlights qualitative research findings that have revealed the perspectives and direct experiences of people living with food insecurity, or those others supporting food-insecure households, that shed light on the role and influence of the socio-economic contextual factors food-insecure people live with day-to-day. Insights from qualitative research that have focused on the granular detail of day-to-day household resource management can help us understand not only how food insecurity differentially impacts individual household members, but also how behavioural responses/food coping strategies are playing into pathways that lead to avoidable ill health such as obesity, diabetes and other chronic health conditions, including mental health problems. This review paper concludes by discussing research and policy implications in relation to food-insecure households containing people with chronic health conditions, and for pregnant women and families with infants and very young children living in the UK today.

Folic acid supplement use is involved in the prevention of neural tube defects, the most common major malformations of the central nervous system(1). Women with childbearing potential are advised to take supplements containing 400mcg/day of folic acid in the period preceding pregnancy until the 12th week of pregnancy, while some women (e.g., women with obesity) require a higher dose of 5mg/day(2). Despite these public health recommendations, there is limited translation to folic acid supplement use behaviours(3). In Northern Ireland, data on women’s selfreported periconception folic acid supplement use can be accessed via the Northern Ireland MATernity System. Using this dataset, the current study reports trends of periconception folic acid supplement use (2015-2020), exploring differences based on women’s age, deprivation, pregnancy planning, gravida, and body mass index (BMI) at their antenatal booking appointment.

R, accessed via the UK Secure eResearch Platform, was used to calculate yearly proportions of selfreported periconception folic acid supplement use. To comply with disclosure controls, only complete cases were retained for analyses. When necessary, years were combined (e.g., instead of yearly prevalences, data on BMI was analysed in 2015-2016, 2017-2018, and 2019-2020) and numerical restrictions were applied (e.g., BMI was restricted to values between 14-70kg/m2). Patient and Public Involvement and Engagement strategies were adopted throughout the study.

Analyses included 132,205 pregnancies. Under a third of pregnancies were primigravida (30.90%), and less than half of pregnancies were conceived by women with a BMI within the healthy range (44.75%). In most cases (58.96%), folic acid supplement use was initiated after, rather than before, conception. Preconception supplement use of 400mcg of folic acid declined between 2015 and 2020 (34.40%-30.03%) and was especially low in young women (i.e., <25 years old), women living in the most deprived areas, and women who did not report planning their pregnancy. Although postconception supplement use of 400mcg also declined, trends exhibited a slight increase in the last year (2019: 51.38%; 2020: 53.94%). Preconception and postconception use of supplements containing 5mg of folic acid increased throughout the study period (3.57%-4.98% and 4.02%-7.67%, respectively). The most notable increase was observed among women with obesity, especially those with BMI≥40kg/m2 (preconception: 8.31%-15.70%; postconception: 23.05%-37.97%).

Overall, these analyses of routinely collected maternity data indicate that folic acid supplement use before pregnancy remains suboptimal in Northern Ireland. The use of higher-dose supplements (5mg/day) is increasing for specific population groups, but it remains at a concerning low level particularly in the preconception period. Although based on women’s self-reported folic acid supplement use, these findings can provide valuable insights for policymakers and healthcare professionals, informing the development of future interventions and campaigns. These may include long-term awareness-raising initiatives and preconception support for all women, especially at-risk groups.

Approximately 40% of the community-dwelling population aged over 65 experiences falls annually, leading to significant morbidity, immobility, and mortality, with reduced muscle strength identified as a major risk factor(1). In comparison to other ethnic populations, Asian older adults often demonstrate weaker muscle strength, with this decline accelerating notably in female Asian older adults as they age(2). Existing research indicates a correlation between vitamin D deficiency (circulating level of 25(OH)D below 50 nmol/L) and sarcopenia in community-dwelling older adults(3). Postmenopausal women, experiencing a decline in oestrogen, face an elevated risk of vitamin D deficiency(4). Notably, vitamin D deficiency is prevalent in Asian populations(5). However, the effectiveness of vitamin D supplementation in promoting muscle strength among community-dwelling postmenopausal Asian women has not been comprehensively investigated. This scoping review aims to provide an overview and synthesis of existing evidence in the literature concerning the efficacy of vitamin D supplementation in enhancing muscle strength among community-dwelling postmenopausal Asian women.

A scoping review was conducted in accordance with PRISMA-ScR recommendations(6). Randomised controlled trials (RCTs) published from 2013 to 2023 were identified through searches conducted in PubMed, EMBASE, and the Cochrane Central databases. Articles would be included if they: (i) were human RCTs with a cross-over or parallel design, (ii) included community-dwelling postmenopausal women, and (iii) investigated the effect of vitamin D supplementation on muscle strength. The review excluded: (i) in vivo animal studies, in vitro cell research, case reports, and observational studies; (ii) studies investigating the effect of vitamin D supplementation combined with other interventions, such as physical exercise, amino acid supplements, or other medication administration records like insulin or hormone therapy; and (iii) studies not in English. Following deduplication and relevance screening, five studies met the criteria, with Jadad scores (methodological quality assessment) of 1, 3, 5, 5, and 5, respectively.

Five RCTs involving a total of 872 subjects were reviewed(7–11). The three studies with Jadad scores of 5 indicated statistically significant and meaningful increases in muscle strength, measured by handgrip strength, with p-values <0.05 and effect sizes of 0.97, 1.75, and 3.83, respectively, indicating large effect sizes. The study with a Jadad score of 3 highlighted such increases only in the younger subgroup (<68 years old). Conversely, the study with a Jadad score of 1 suggested no significant changes in muscle strength.

In conclusion, this review suggests promising outcomes for vitamin D supplementation in enhancing muscle strength among postmenopausal Asian women. The prevalence of vitamin D deficiency underscores potential health benefits, but heterogeneity in study designs, Jadad scores, and age subgroup responses necessitates cautious interpretation. Further high-quality research is imperative to elucidate optimal dosages and durations, ensuring a nuanced understanding of the relationship between vitamin D supplementation and muscle strength.

The development of multiple long-term conditions (MLTC) has been shown to be associated with low-grade chronic inflammation(1). The Dietary Inflammatory Index (DII®) is a literature-based dietary score that was developed to measure the potential impact of diet on the inflammatory status of an individual(2). In this study, we aimed to validate the DII® score against biomarkers, including high- sensitivity C-reactive protein (hs-CRP), and plasma concentrations of vitamin C, retinol and α- tocopherol in European Prospective Investigation Into Cancer and Nutrition (EPIC)-Norfolk participants, aged 39–79 years at baseline(3).

The DII® score was calculated using a 130-item Food Frequency Questionnaire collected at baseline, between 1993 and 1997. The dietary intakes were adjusted to a 2000 kcal/day diet, to assess diet quality independently of diet quantity. Non-fasting serum cholesterol, hs-CRP, and plasma α- tocopherol, vitamin C and retinol concentrations were also measured at this time-point. Data collected via a self-administered Health and Lifestyle Questionnaire were used to establish classification of a number of variables. Analyses were conducted on sub-samples with a DII® score and measures of hs-CRP (8,034 men and 9,861 women), and concentrations of vitamin C (9,866 men and 11,702 women), retinol (3,673 men and 3,517 women) and cholesterol-adjusted α- tocopherol (3,623 men and 3,476 women). Analysis of covariance and linear regression were used to study associations across sex-specific quintiles of the DII® score (adjusted for age, BMI, smoking status, physical activity, social class and educational level), where a higher score indicates a more pro-inflammatory diet.

Mean concentrations in men and women were 2.99 and 3.09 mg/L for hs-crp, 47 and 59 μmol/L for vitamin C, 53 and 50 μg/dL for retinol and 4.34 and 4.42 μmol/mmol for cholesterol-adjusted α- tocopherol, respectively. In both men and women, mean hs-CRP was higher if the diet was more pro-inflammatory (p-trend = 0.02 in men and 0.07 in women), while concentrations of vitamin C, retinol and α-tocopherol were significantly lower (p-trend < 0.001). Positive associations for hs-CRP, but negative associations for plasma concentrations of vitamin C, retinol and α-tocopherol were evident in both men and women, after adjustments for covariates (p-trend < 0.001). The differences between Q1 and Q5 adjusted means for hs-CRP, vitamin C, retinol and α-tocopherol were +9.4%, -22.1%, -3.9% and -8.6% in men and +7.9%, -17.5%, -4.8% and -7.6% in women, respectively.

We observed statistically significant positive associations between the DII® score and hs-CRP, a well-known inflammatory biomarker, whilst significant negative associations were found for circulating concentrations of three anti-inflammatory vitamins, after adjustment for covariates. These findings indicate that the DII® score is a valid measure of the inflammatory potential of diet in these middle-aged and old adults, making it possible to study the inflammatory role of diet in MLTC development.

Calcium and vitamin D have well-established roles in maintaining calcium balance and bone health. Decades of research in human subjects and animals have revealed that calcium and vitamin D also have effects on many other organs including male reproductive organs. The presence of calcium-sensing receptor, vitamin D receptor, vitamin D activating and inactivating enzymes and calcium channels in the testes, male reproductive tract and human spermatozoa suggests that vitamin D and calcium may modify male reproductive function. Functional animal models have shown that vitamin D deficiency in male rodents leads to a decrease in successful mating and fewer pregnancies, often caused by impaired sperm motility and poor sperm morphology. Human studies have to a lesser extent validated these findings; however, newer studies suggest a positive effect of vitamin D supplementation on semen quality in cases with vitamin D deficiency, which highlights the need for initiatives to prevent vitamin D deficiency. Calcium channels in male reproductive organs and spermatozoa contribute to the regulation of sperm motility and capacitation, both essential for successful fertilisation, which supports a need to avoid calcium deficiency. Studies have demonstrated that vitamin D, as a regulator of calcium homoeostasis, influences calcium influx in the testis and spermatozoa. Emerging evidence suggests a potential link between vitamin D deficiency and male infertility, although further investigation is needed to establish a definitive causal relationship. Understanding the interplay between vitamin D, calcium and male reproductive health may open new avenues for improving fertility outcomes in men.