- Correlations between cognitive, behavioural and psychological findings and levels of vitamin B12 and folate in patients with dementia. Engelborghs, S., Vloeberghs, E., Maertens, K., Mariën, P., Somers, N., Symons, A., Clement, F., Ketels, V., Saerens, J., Goeman, J., Pickut, B.A., Vandevivere, J., De Deyn, P.P. International journal of geriatric psychiatry. (2004)