Depression in Elderly Women Linked to Vitamin B-12 Deficiency
May 11, 2000 -- Researchers have found a link between depression and
deficiencies of vitamin B-12, which is thought to be essential to proper
functioning of our brains and nervous systems. In a study of 700 elderly women,
those with vitamin B-12 deficiencies were twice as likely as others to be
"Our most important finding was that vitamin B-12 deficiency and
depression are correlated. This is the first proof of this association,"
says researcher Brenda W.J.H. Penninx, PhD. But Penninx, from the Sticht Center
on Aging of Wake Forest University, tells WebMD that researchers cannot be sure
whether vitamin B-12 causes depression or vice versa.
A deficiency of either vitamin B-12 or folate can result in neurological
and/or psychiatric disease that becomes irreversible if not treated properly,
says Penninx, main author of the study published in the American Journal of
"This connection is supported by findings that psychiatric patients,
especially depressed patients, frequently are found to have abnormalities in
vitamin B-12 and folate status," Penninx and colleagues write.
"However, since the studies thus far have been restricted to psychiatric
patients, it is unknown whether vitamin B-12 and folate deficiencies affect
depressed mood in the general, community-dwelling population."
The researchers studied 700 disabled, nondemented women aged 65 and older
living in the community. They measured their blood levels of vitamin B-12 and
folate, and determined their levels of depression. Participants were
categorized as having no depression, mild depression, or severe depression.
About one-third of the women were found to be depressed. About 14% were
mildly depressed, and 17.4% were severely depressed.
More than 17% of all the women had low levels of vitamin B-12, and those
with vitamin B-12 deficiency were twice as likely to be severely depressed as
those who were not. Further, women who were either not depressed or were mildly
depressed were less likely to be among those who had the deficiency. Folate
deficiency was not associated with depression status.
There are a couple of possible explanations for the findings, Penninx says.
"The first option is that depressed people are more likely to develop
vitamin B-12 deficiency," she says. "This is a very likely explanation.
We know depressed people are more likely to have less healthy eating habits.
They often eat not often enough, eat fatty foods more often, or are more likely
to overeat. ... We don't have any information in this study about food
The other option is that people with vitamin B-12 deficiency are more likely
to develop depression. Penninx feels there is no strong evidence for this
Jonathan E. Alpert, MD, PhD, of Harvard University, feels differently.
"We know that severe B-12 deficiency can lead to neurological symptoms, so
it's not implausible to think it can contribute to depression, even though that
association hasn't been very strong in previous [studies]," says Alpert,
who reviewed the study for WebMD. He notes, however, that the association
between the women's actual levels of B-12 and their depression was not very
strong in the current study.