Timetable and Budget
| Description | Deadline/Limit |
|---|---|
| Deadline for Stage 1 applications | 13 February 2024, 1 PM |
| Notification of outcome of Stage 1 Application | April 2024 |
| Deadline for Stage 2 application | 04 June 2024, 1 PM |
| Notification of outcome of Stage 2 Application | November 2024 |
| Earliest Potential Project Start | December 2024 |
| Project Duration | 12-24 Months |
| Budget | Up to £500,000 |
Introduction
The National Institute for Health and Care Research (NIHR) Policy Research Programme (PRP) invites applications for a single research project on iron bioavailability in adults and children.
Background on Scientific Advisory Committee on Nutrition (SACN)
The UK Scientific Advisory Committee on Nutrition (SACN) is a committee of the Office for Health Improvement and Disparities (OHID), which is part of the Department of Health and Social Care.
It provides independent scientific advice on, and risk assessment of, nutrition and related health issues. It advises the 4 UK governments and is supported by a scientific secretariat based at OHID.
- SACN’s advice covers the scientific aspects of nutrition and health with specific reference to:
nutrient intakes and nutritional status of the population - nutrient content of individual foods and advice on individual nutrients and diet as a whole, including the definition of a balanced diet
- monitoring and surveillance of the above aspects
- nutritional issues which affect wider public health policy issues, including conditions where nutritional status is one of a number of risk factors (such as cardiovascular disease, cancer, diabetes, oral health, osteoporosis and obesity)
- research requirements for the above.
SACN’s remit is to:
- assess the benefits and risks of nutrients, dietary patterns, food, or food components to health by evaluating scientific evidence
- make dietary recommendations for the UK population (including vulnerable and/or diverse groups) based on its assessment.
Consideration of vulnerable groups (such as infants, adolescents and older adults), racially and ethnically diverse groups and health inequality underpins all SACN evidence evaluations. Where relevant, and when available evidence allows, SACN also considers beliefs and cultural influences.
Background on the assessment of dietary iron bioavailability to inform dietary reference values for iron
UK dietary recommendations are based on advice from SACN and its predecessor the Committee on Medical Aspects of Food and Nutrition Policy (COMA).
At its horizon scan meeting in November 2020, SACN agreed to prioritise consideration of the bioavailability of iron, and specifically, to focus on the assessment of dietary iron bioavailability and how this might impact on dietary reference values (DRVs) for iron. Accordingly, it was agreed that a SACN working group would be established to determine whether evidence published since publication of SACN’s Iron and Health Report (2011), including development of a predictive modelling tool for estimating dietary iron bioavailability (Fairweather-Tait et al, 2017) warranted an update to the bioavailability estimate for iron and consequently a review of the DRVs for iron. Consideration of this topic has been paused as a result of delays to an anticipated systematic review by the FAO/WHO expert group updating DRVs for children aged 0 to 36 months including iron, which would inform this work. Our understanding is that this review is delayed for the foreseeable future with no expected start date.
In the UK, the DRVs for iron were set by COMA in 1991. COMA used a factorial method to assess iron requirements based on estimates of obligatory loses, menstrual losses and accretion of iron in synthesised tissues. Requirements for dietary iron were then estimated assuming 15% absorption of dietary iron, which was considered typical for most population groups in industrialised countries (FAO, 1988).
In its 2011 report on Iron and Health, SACN noted that the main determinant of the amount of dietary iron absorbed by the body is the systemic need for iron. SACN also noted that DRVs for iron are derived from limited data and that the assumed absorption of 15% is largely based on short term studies usually carried out in iron replete individuals in whom iron absorption would be downregulated. Short-term studies do not allow for adaptive responses that occur over a longer time period, nor for the nature of this adaptation in response to systemic needs for iron. In addition, SACN noted that “While substantial proportions of the UK population appear to have iron intakes below dietary recommendations for iron, this is not clearly consistent with the low prevalence of poor iron status. This might be because there are important uncertainties in the DRVs for iron intake which may be too high, particularly for girls and women of reproductive age. It is recommended that the DRVs for iron should be reviewed when more data become available”.
The UK National Diet and Nutrition Survey (NDNS) data show higher proportions of the population with insufficient dietary intakes compared to the proportions with iron deficiency through blood samples. This suggests that the DRVs may be set too high.
The 2011 SACN report included the following research recommendation: good quality dose-response data are required to enable a reassessment of the DRVs for iron. Knowledge of the systemic regulation and mediation of iron homeostasis should be applied to characterise better the responses to increased and reduced systemic needs for iron and the development, or better validation, of existing markers used to assess the adequacy of iron status in populations and individuals”. It is our understanding that the evidence base has matured since 2011 and there is sufficient evidence to reassess this issue.
If more recent evidence on dietary iron bioavailability indicates/supports that DRVs for iron are too high this would have important implications for a range of nutrition policies.
Policy need
Ensuring that food provided in a number of settings (e.g. early years settings, schools, hospitals, prisons) meets iron requirements is a key limiting factor in menu planning and food provision.
If iron requirements are found to be lower than current DRVs, this would mean lower meat intakes are needed to meet iron requirements with associated benefits across many settings/situations.
Policy implications of lower iron DRV:
- Shift to lower red meat/meat intakes to meet iron requirements would reduce food provision costs across early years settings, schools, hospitals, prisons etc
- Shift to lower meat intakes would have positive impacts for sustainability/climate change mitigation and for human health (Climate Change Committee, 2020)
- Shift to lower red meat and processed meat supports SACN’s recommendations in 2011 iron and health report that adults with relatively high intakes of red and processed meat (that is, more than 90g/day) should consider reducing their intakes in order to reduce colo-rectal cancer risk
- reduce reliance on flour-based desserts to meet requirements (Bread and Flour Regs 1998 require all wheat flour except wholemeal flour to have iron in them) - and therefore reduced free sugar/saturated fat/energy
Research priorities
Conduct a systematic review of primary research on iron requirements for children (aged 0 – 18 years) to inform reassessment of iron dietary reference values for the UK population.
- Agree literature search strategy including: research question(s); databases to search; PICO; inclusion and exclusion criteria
- Systematic search of the scientific literature in major databases (including studies of nutrient requirements, absorption and loss; balance studies; modelling) - note that evidence should be restricted to populations applicable to the UK.
- Data extraction from relevant studies meeting the inclusion criteria (in duplicate)
- Quality assessment of included studies and evidence/data synthesis and analysis
Conduct an updated systematic review of primary research on dietary iron bioavailability to inform reassessment of iron dietary reference values for the UK populations (all age groups)
- Agree literature search strategy including: research question(s); databases to search; PICO; inclusion and exclusion criteria
- Systematic search of the scientific literature in major databases (including studies of nutrient requirements, absorption and loss; balance studies; modelling)
- Data extraction from relevant studies meeting the inclusion criteria (in duplicate)
- Quality assessment of included studies and evidence/data synthesis and analysis
Based on findings from the systematic reviews, generate a range of iron bioavailability values for a range of diets (including those containing little or no meat or other animal products) that are applicable to UK population groups (including consideration of metabolic adaptation affecting efficiency of iron absorption and utilisation in diverse population groups), and taking into account different serum ferritin concentrations (as an indicator of body iron stores). In particular, i) consider the applicability of the modelling tool developed by Fairweather-Tait et al (2017) for adults in the UK; ii) determine whether this model is applicable to children in the UK or whether a different model of dietary iron bioavailability needs to be developed; iii) consider whether different models are needed for different age groups; iv) adapt and/or develop a modelling tool(s) for the UK population and its subgroups, as appropriate.
Using nationally representative data, undertake detailed modelling of projected dietary reference values for iron intakes based on estimated bioavailability of iron for the UK population. Consider any implications specific to the UK setting (for example, issues relating to specific population groups, dietary intakes and different dietary sources, and iron status).
Areas out of scope for this programme of work
This call is restricted to applications on iron bioavailability; consideration of other dietary components is not in scope other than in relation to how these might impact the uptake of iron.
In line with SACN’s remit, this call is restricted to iron requirements for the general UK population, including pregnant and lactating women and older adults; it does not cover management of clinical conditions.
Eligibility
Eligibility for the NIHR PRP is laid out in our Standard Information for Applicants and applies to all calls unless otherwise stated in the individual research specification.
Technical requirements / Expertise required
- Nutrition science
- Food science
- Systematic reviewing
- Statistics/modelling
Outputs
Applicants are asked to consider the timing and nature of deliverables in their proposals. Policymakers will need research evidence to meet key policy decisions and timescales, so resource needs to be flexible to meet these needs. Researchers will be expected to work with relevant DHSC officials from the outset to ensure the research aligns with priorities and is focused on needs and impact. A meeting to discuss policy needs with DHSC officials will be convened as a matter of priority following contracting.
To ensure research remains impact focused, practical, translatable and solution driven, during the course of the research, researchers will be expected to engage in regular communications with officials from DHSC. In particular, this will include liaison officers and financial leads in the Science Research and Evidence (SRE) directorate and nutrition science and policy leads in the Office for Health Improvement and Disparities (OHID). Furthermore, researchers will be expected to work with DHSC officials to establish key milestones and agree outputs, such as internal documents/updates, draft publications, presentations of findings to DHSC and potentially other key stakeholders.
Budget and duration
We are anticipating that the research will take between 12-24 months and cost up to £500,000. Costings can include up to 100% full economic costing (FEC) but should exclude output VAT. Applicants are advised that value for money is one of the key criteria that peer reviewers and commissioning committee members will assess applications against.
Management arrangements
A research advisory group including, but not limited to, representatives of DHSC, other stakeholders, and the successful applicants for the research should be established. The advisory group will provide guidance, meeting regularly over the lifetime of the research. The successful applicants should be prepared to review research objectives with the advisory group, and to share emerging findings on an ongoing basis. They will be expected to:
- Provide regular feedback on progress
- Produce timely reports to the advisory group
- Produce a final report for sign off
Research contractors will be expected to work with nominated officials in DHSC, its partners and the NIHR. Key documents including, for example, research protocols, research instruments, reports and publications must be provided to DHSC in draft form allowing sufficient time for review.
Guidance on Health and Care Inequalities and associated data collection within NIHR PRP Research
Health and care Inequalities is a high priority area within the Department of Health and Social Care and the NIHR and is often present in a majority of funded projects.We are now assessing all NIHR research proposals in relation to health inequalities. We ask that you please clearly identify in the research plan section of the application whether your application has an inequalities component or theme as well as how this research hopes to impact inequalities or not. Please also detail the core set of inequality breakdown data that will be collected, if applicable. More information on this request can be found in the Standard information for applicants.
References and key documents
1. Bates B, Collins D, Kerry J, Page P, Roberts C, Steer T, et al. National Diet and Nutrition Survey Rolling programme Years 9 to 11 (2016/2017 to 2018/2019) 2020 [Available from:NDNS: results from years 9 to 11 (2016 to 2017 and 2018 to 2019)
2. COMA. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom London; 1991.
3. Fairweather-Tait SJ, Jennings A, Harvey LJ, Berry R, Walton J, Dainty JR. Modeling tool for calculating dietary iron bioavailability in iron-sufficient adults. Am J Clin Nutr. 2017;105(6):1408-14.
4. FAO/WHO. Requirements of vitamin A, iron, folate and vitamin B12. Report of a Joint FAO/WHO Expert Consultation. . Rome: FAO; 1988.
5. SACN. Iron and Health 2011 [Available from:SACN Iron and Health Report