Taking vitamin B12 and folic acid supplements might not reduce the risk of memory problems after all.
The study, which is the largest to date on the subject, looked at people with high blood levels of the amino acid homocysteine. This amino acid has been linked to Alzheimer's disease, the American Academy of Neurology reported.
To make their findings the researchers looked at 2,919 people with an average age of 74 who took either a tablet with 400 micrograms of folic acid and 500 micrograms of vitamin B12 or a placebo for a period of two years. Tests on memory and thinking skills were performed at both the beginning and end of the trial. Through these observations the researchers were not able to find a link between these supplements and protection against memory decline.
"While the homocysteine levels decreased by more in the group taking the B vitamins than in the group taking the placebo, unfortunately there was no difference between the two groups in the scores on the thinking and memory tests," said Rosalie Dhonukshe-Rutten of Wageningen University in Wageningen, the Netherlands.
People taking these supplements in the study did experience some small positive effects, Healthline reported. One analysis of the data found people with low blood levels of holotranscobalamin (the active form of B12) were able to improve their thinking speed if they took vitamin B12 and folic acid supplements.
Although the study did not find significant cognitive benefits associated with vitamin B12 and folic acid supplements, the researchers note that vitamin B12 levels are still a significant factor in overall health and patients are urged to talk to their doctors about maintaining them.
"B12 is an important vitamin both for the central and peripheral nervous systems," said Zwerling. "A B12 deficiency presents in many ways: it can present as hand numbness, distal foot numbness, cognitive changes, gait instability."
Good sources of vitamin B12 include: meat; cod and salmon; dairy products such as milk and cheese; eggs; and some fortified breakfast cereals. Folic acid can be found in many dark green vegetables such as broccoli and asparaugs as well as in liver, chickpeas, and brown rice, the National Health Services reported.
The findings were published Nov. 12 in the journal Neurology.
