Taking daily doses of vitamin B12 and folic acid are not as helpful against memory loss as previously thought, according to a large scale research led by Nikita van der Zwaluw, PhD, of Wageningen University, the Netherlands. The study has been published in Neurology.
Higher levels of homocysteine may cause both strokes and dementia. Vitamin B12 and folic acid have been regarded as effective agents against homocysteine. But even if the doses achieved their aim at the end of the clinical trial, people who took the supplements have not seen any improvement in their memory.
“Since homocysteine levels can be lowered with folic acid and vitamin B12 supplements, the hope has been that taking these vitamins could also reduce the risk of memory loss and Alzheimer’s disease,” said study author Rosalie Dhonukshe-Rutten.
About 3,000 people took 400 micrograms of folic acid and 500 micrograms of vitamin B12 or a placebo each day for two years. The sample contained people with an average age of 74 and with high levels of homocysteine.
Researchers administered a series of memory tests to the participants before and after the trial. Unfortunately, results showed that the supplements had no beneficial effects, at least in what regards memory performance. The small difference observed between those who took the supplements and those who took the placebo could very well be explained by chance.
“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 Dhonukshe-Rutten.
Longer follow-ups are needed to verify if the supplements will have effects on the longer term, Dr Eric Karran, director of research at Alzheimer’s Research UK told the BBC. Karran was not involved in the study. He suggested that the sample should have included people who already suffer from memory loss.
According to Dhonukshe-Rutten, the sample happened to include a very healthy population with already elevated Vitamin B levels.
Vitamin B has never been touted as a cognitive booster, Professor David Smith, FMedSci, founding director of the Oxford Project to Investigate Memory and Ageing, United Kingdom, told Medscape Medical News. Smith said that further studies are necessary to clarify the role of the supplements in Alzheimer’s disease prevention. Around 20 percent of dementia cases could be prevented with the help of Vitamin B and folic acid, if they are proven to be effective.