Memory and thinking problems can be a sign of vitamin B12 deficiency, research finds.
People with low vitamin B12 can find it harder to sustain attention, learn words and names and solve puzzles.
Low levels of the vital vitamin have also been linked by research to brain shrinkage.
Vitamin B12, along with folate, help to protect the cognitive function of older people.
Good sources of vitamin B12 include fish, poultry, eggs and low-fat milk.
Fortified breakfast cereals also contain vitamin B12.
The study included 1,459 older people whose vitamin B12 and folate levels were measured.
They were also given tests of their cognitive skills.
Dr Martha Savaria Morris, the study’s first author, explained the results:
“We found a strong relationship between high folate status and good cognitive function among people 60 and older who also had adequate levels of vitamin B12.”
Folates include vitamin B9, folacin and folic acid.
Some of the best dietary sources of folates include:
- and whole-grains.
Folate levels are particularly high in chickpeas, yeast extract, lentils and broad beans.
Dr Morris said:
“People with normal vitamin B12 status performed better if their serum folate was high.
But for people with low vitamin B12 status, high serum folate was associated with poor performance on the cognitive test.”
In contrast, low vitamin B12 was problematic:
“For seniors, low vitamin B12 status and high serum folate was the worst combination.
Specifically, anemia and cognitive impairment were observed nearly five times as often for people with this combination than among people with normal vitamin B12 and normal folate.”
People who may have difficulty getting enough vitamin B12 include vegetarians and those with some digestive disorders, such as Crohn’s disease.
Dr Morris concluded:
“Our findings support the often-expressed idea that many seniors would benefit from more folate, but the research shows that we must look at the effects this would have on seniors with age-related vitamin B12 deficiency, who may be more numerous than once realized.”
The study was published in the American Journal of Clinical Nutrition (Morris et al., 2007).