BackgroundVitamin D3 is essential for calcium metabolism and exerts pleiotropic effects, including neuroprotective activities in cognition. Its insufficiency has been linked to dementia, Alzheimer's disease, and cognitive impairments. The association between vitamin D3 and particular cognitive functions, including memory recall and word intrusion, remains imprecise, particularly among diverse ethnic and socioeconomic groups.ObjectiveTo examine the relationship between vitamin D3 levels with memory recall and word intrusion in individuals aged 60 and above, emphasizing demographic differences.MethodsData was collected from 2759 individuals in the NHANES 2011-2014 surveys. Cognitive performance was evaluated with the CERAD Word Learning, Animal Fluency, and Digit Symbol Substitution assessments. Factor analysis was employed to identify two cognitive domains: F1 'Memory Recall' and F2 'Word Intrusion'. Linear and quantile regression models, controlled for demographic variables, were performed to assess the association between vitamin D3 levels and cognitive domains. Bootstrap techniques were used for standard error estimation, and nonparametric regression was applied to identify non-linear correlations.ResultsVitamin D3 levels positively correlated in linear models and quantile regression with F1 'Memory Recall' at diminished cognitive function levels. F2 was not associated with vitamin D3. Socioeconomic factors influenced these correlations, revealing inequalities among ethnic and income groups.ConclusionsElevated vitamin D3 levels correlate with improved memory recall, especially in individuals with lower cognitive percentiles. These findings suggest the potential of vitamin D3 to alleviate cognitive decline, including Alzheimer's disease, highlighting the need for focused interventions, particularly in underrepresented demographic groups.