Introduction: There is an emergent association between vitamin D deficiency (VDD) and the risk of SARS-CoV-2 infection. The prevalence of VDD in Ireland is high,(1)(2)(3) particularly in older institutionalised adults (4) and low SES groups (2) as a consequence of suboptimal sun exposure, inadequate dietary intake, unfavourable lifestyle habits, and low supplementation rates; these same groups are at higher risk of SARS-CoV-2 infection.(5) This research project aimed to establish a method for area-level prediction of VDD to aid in the identification of spatial areas at higher risk of VDD which might also be more vulnerable to SARS-CoV-2 infection.

Methods: This study was a retrospective cross-sectional analysis of area-level vitamin D status amongst community-dwelling adults in Ireland. Serum 25(OH)D concentrations from 7,708 GP-ordered patient samples from counties Dublin, Meath, Wicklow, and North Kildare were derived from the electronic patient database at St James’s Hospital, Dublin. These samples were geo-coded by the electoral division (ED) of the residential address using the Health Atlas Ireland/GeoDirectory application. The demographic profile (ethnic mix) and socioeconomic status (the relative Pobal Haase-Pratschke affluence/deprivation score) at the ED level was based on the Census 2016 Small Area Population Statistics (SAPS) published by the Central Statistics Office. The associations between the demographic and socioeconomic parameters and the mean and median ED-level 25(OH)D were examined by univariate (one-way ANOVA with Tukey’s post hoc multiple comparison test, Kruskal-Wallis with Dunn’s post hoc multiple comparison test) and multivariate (linear regression, multinomial logistic regression) analyses.

Results: There were 412 EDs with indicative 25(OH)D measures. VDD at area-level was defined as mild if the mean ED-level 25(OH)D was 50 - 74 nmol/L, moderate if the mean ED-level 25(OH)D was 30 - 49 nmol/L, or severe if the mean ED-level 25(OH)D was less than 30 nmol/L. ED-level socioeconomic disadvantage was associated with a higher risk of mild, moderate, and severe VDD (OR 1.042 for mild VDD, p = 0.004; OR 1.059 for moderate VDD, p = 0.003; OR 1.060 for severe VDD, p = 0.071 with each one-unit reduction in relative deprivation index score). Each percentage point increment in the prevalence of Asian and Asian Irish ethnicity at ED-level was associated with a higher risk of mild VDD (OR 1.120, p = 0.041).

Conclusion: Low socioeconomic status and the prevalence of non-white ethnicity at ED-level are predictive of VDD in community-dwelling Irish adults. These findings support the use of area-level population statistics to predict VDD at area-level.

References: 1 Laird E, et al. J Gerontol Ser A 2018; 73: 519–525. 2 Griffin TP, et al. J Gerontol Ser A 2020; 75: 2418–2425. 3 Madden JM, et al. Int J Environ Res Public Health 2021; 18: 6285. 4 Scully H, et al. Nutrients 2020; 12: 2663.
5 Laird E, et al. Nutrients 2020; 12: 3674.

**Introduction**: There is an emergent association between vitamin D deficiency (VDD) and the risk of SARS-CoV-2 infection. The prevalence of VDD in Ireland is high,**^(1)(2)(3)^** particularly in older institutionalised adults **^(4)^** and low SES groups **^(2)^** as a consequence of suboptimal sun exposure, inadequate dietary intake, unfavourable lifestyle habits, and low supplementation rates; these same groups are at higher risk of SARS-CoV-2 infection.**^(5)^** This research project aimed to establish a method for area-level prediction of VDD to aid in the identification of spatial areas at higher risk of VDD which might also be more vulnerable to SARS-CoV-2 infection.

**Methods**: This study was a retrospective cross-sectional analysis of area-level vitamin D status amongst community-dwelling adults in Ireland. Serum 25(OH)D concentrations from 7,708 GP-ordered patient samples from counties Dublin, Meath, Wicklow, and North Kildare were derived from the electronic patient database at St James’s Hospital, Dublin. These samples were geo-coded by the electoral division (ED) of the residential address using the Health Atlas Ireland/GeoDirectory application. The demographic profile (ethnic mix) and socioeconomic status (the relative Pobal Haase-Pratschke affluence/deprivation score) at the ED level was based on the Census 2016 Small Area Population Statistics (SAPS) published by the Central Statistics Office. The associations between the demographic and socioeconomic parameters and the mean and median ED-level 25(OH)D were examined by univariate (one-way ANOVA with Tukey’s _post hoc_ multiple comparison test, Kruskal-Wallis with Dunn’s _post hoc_ multiple comparison test) and multivariate (linear regression, multinomial logistic regression) analyses.

**Results**: There were 412 EDs with indicative 25(OH)D measures. VDD at area-level was defined as mild if the mean ED-level 25(OH)D was 50 - 74 nmol/L, moderate if the mean ED-level 25(OH)D was 30 - 49 nmol/L, or severe if the mean ED-level 25(OH)D was less than 30 nmol/L. ED-level socioeconomic disadvantage was associated with a higher risk of mild, moderate, and severe VDD (OR 1.042 for mild VDD, p = 0.004; OR 1.059 for moderate VDD, p = 0.003; OR 1.060 for severe VDD, p = 0.071 with each one-unit reduction in relative deprivation index score). Each percentage point increment in the prevalence of Asian and Asian Irish ethnicity at ED-level was associated with a higher risk of mild VDD (OR 1.120, p = 0.041).

**Conclusion**: Low socioeconomic status and the prevalence of non-white ethnicity at ED-level are predictive of VDD in community-dwelling Irish adults. These findings support the use of area-level population statistics to predict VDD at area-level.

**References**: **^1^** Laird E, et al. _J Gerontol Ser A_ 2018; 73: 519–525. **^2^** Griffin TP, et al. _J Gerontol Ser A_ 2020; 75: 2418–2425. **^3^** Madden JM, et al. _Int J Environ Res Public Health_ 2021; 18: 6285. **^4^** Scully H, et al. _Nutrients_ 2020; 12: 2663.
**^5^** Laird E, et al. _Nutrients_ 2020; 12: 3674.

The association between area-level demographic and socioeconomic parameters and vitamin D status in Ireland

Modern nutrition science is young: It is less than one century since the first vitamin was isolated in 1926. Nutrition science stands upon research conducted by academia, the private sector, and nongovernmental organisations, often in collaboration across these sectors. Its evidence base is of fundamental importance to the solving of current challenges and complexities, optimising outcomes, and the prevention of harm.

In order to remain relevant, nutrition science must address the global challenges, including ensuring nutrition security for all, in line with the UN Sustainable Development Goals and in the context of the post-COVID era. It is timely to take stock and consider how nutrition science must move forward.

The conference is designed integrate three symposium sessions which will commence with reflection on historical exemplars of nutrition achievements, then moving the discussion to current challenges which face the discipline and will culminate in scoping the outlook for nutrition science going forward.