Introduction: Cognitive function typically declines with age, adversely affecting quality of life in older people1,2. Many factors, both modifiable and non-modifiable, are recognized to contribute to this decline. Among the nutrition factors, evidence suggest a role for low/deficient status of folate and/or the interrelated B-vitamins, B12, B6, and riboflavin3. These B-vitamins are interlinked through their roles in one-carbon metabolism, crucial for sustaining numerous pathways required for brain functioning, but few studies have investigated all four nutrients in relation to cognitive function4. The aim was to investigate relationships between B-vitamin biomarkers and risk of cognitive dysfunction. We hypothesized that lower B-vitamin status, and/or higher concentrations of the related metabolite homocysteine, will be associated with cognitive dysfunction.
Methods: Data were analysed from the Trinity-Ulster-Department of Agriculture (TUDA) of community-dwelling older adults recruited from the island of Ireland (2008–12). Of 5186 TUDA participants, 3973 fulfilled the inclusion criteria for the current investigation. B-vitamin biomarkers, namely, red blood cell folate, serum B12, plasma pyridoxal-5-phosphate (PLP; B6), erythrocyte glutathione reductase activation coefficient (EGRac; riboflavin) and plasma homocysteine were measured. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to measure global cognition and its component cognitive domains (visual-spatial, language, attention, immediate and delayed memory). Cognitive dysfunction was defined as the lowest 20% of scores.
Results: An increased risk of cognitive dysfunction was observation in the lowest compared to the highest tertile of riboflavin status, after adjustment for covariates, with odds ratios (OR, 95% CI) of 1.352 (1.082-1.690, P=0.008) for global cognition, 1.256 (1.014-1.554, P=0.036) for language and 1.255 (1.022-1.541, P=0.030) for delayed memory functions. In addition, an increased risk of cognitive dysfunction in the highest compared to the lowest tertile of homocysteine concentrations for global cognition (OR 1.632, 95% CI: 1.262-2.110, P<0.001) and for visual-spatial, language and attention functions (increased risk of 41%, 37% and 62% respectively, P<0.01). No significant associations were observed for biomarkers of folate, vitamin B12 or B6 with risk of cognitive dysfunction.
Conclusion: These preliminary findings suggest that low riboflavin status and elevated homocysteine were each associated with greater risk of cognitive dysfunction when assessed using global RBANS and specific domain scores. Further investigation is required in relation to the role of B-vitamins in relation to cognitive health, particularly riboflavin a much-overlooked nutrient that is rarely measured in human studies.

**Introduction:** Cognitive function typically declines with age, adversely affecting quality of life in older people1,2. Many factors, both modifiable and non-modifiable, are recognized to contribute to this decline. Among the nutrition factors, evidence suggest a role for low/deficient status of folate and/or the interrelated B-vitamins, B12, B6, and riboflavin3. These B-vitamins are interlinked through their roles in one-carbon metabolism, crucial for sustaining numerous pathways required for brain functioning, but few studies have investigated all four nutrients in relation to cognitive function4. The aim was to investigate relationships between B-vitamin biomarkers and risk of cognitive dysfunction. We hypothesized that lower B-vitamin status, and/or higher concentrations of the related metabolite homocysteine, will be associated with cognitive dysfunction.
**Methods:** Data were analysed from the Trinity-Ulster-Department of Agriculture (TUDA) of community-dwelling older adults recruited from the island of Ireland (2008–12). Of 5186 TUDA participants, 3973 fulfilled the inclusion criteria for the current investigation. B-vitamin biomarkers, namely, red blood cell folate, serum B12, plasma pyridoxal-5-phosphate (PLP; B6), erythrocyte glutathione reductase activation coefficient (EGRac; riboflavin) and plasma homocysteine were measured. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to measure global cognition and its component cognitive domains (visual-spatial, language, attention, immediate and delayed memory). Cognitive dysfunction was defined as the lowest 20% of scores.
**Results:** An increased risk of cognitive dysfunction was observation in the lowest compared to the highest tertile of riboflavin status, after adjustment for covariates, with odds ratios (OR, 95% CI) of 1.352 (1.082-1.690, _P_=0.008) for global cognition, 1.256 (1.014-1.554, _P_=0.036) for language and 1.255 (1.022-1.541, _P_=0.030) for delayed memory functions. In addition, an increased risk of cognitive dysfunction in the highest compared to the lowest tertile of homocysteine concentrations for global cognition (OR 1.632, 95% CI: 1.262-2.110, _P_<0.001) and for visual-spatial, language and attention functions (increased risk of 41%, 37% and 62% respectively, _P_<0.01). No significant associations were observed for biomarkers of folate, vitamin B12 or B6 with risk of cognitive dysfunction.
**Conclusion:** These preliminary findings suggest that low riboflavin status and elevated homocysteine were each associated with greater risk of cognitive dysfunction when assessed using global RBANS and specific domain scores. Further investigation is required in relation to the role of B-vitamins in relation to cognitive health, particularly riboflavin a much-overlooked nutrient that is rarely measured in human studies.

LB5 - B-vitamin biomarkers and risk of cognitive dysfunction in older adults: preliminary analysis from the TUDA study.

Unique to the new Congress (previously the Summer Conference) is that you will have greater opportunity to engage with more nutrition science than ever before. In 2024 the core programme will be delivered by the Irish Section of The Nutrition Society, supported by the Science Committee. The theme of these symposia will be ‘new data – focused approaches and challenges’. Outside of the core programme you will have the chance to hear the latest research from the Society’s partner organisations, universities, the private sector and more, on a diverse range of research.