Among a group of disabled women aged 65 and older who were tracked for several years, those who had a vitamin B 12 deficiency were twice as likely to suffer severe depression as those who did not....

Among a group of disabled women aged 65 and older who were tracked for several years, those who had a vitamin B₁₂
deficiency were twice as likely to suffer severe depression as those who did not. (Source: American Journal of Psychiatry 157 [2000]: 715)