Being in the low range of vitamin B12 recommendations exposes to an increased risk of cognitive impairment, especially in seniors, according to a new study.
- “Healthy” levels of vitamin B12 are not enough to prevent neurological decline, according to a new study.
- Researchers call to redefine vitamin B12 deficiency rates.
- Vitamin B12 plays a role in the synthesis of DNA or the functioning of the nervous system. It is found in particular in offal, fish, seafood and eggs.
Vitamin B12 (or cobalamine) plays an essential role in the synthesis of DNA and fatty acids as well as in the functioning of the nervous system. To stay healthy, healthcare professionals recommend having a rate of at least 148 pmol/l. However, a new study by the University of California in San Francisco reveals that being in the low range of the “Normal beach” Vitamin B12 is not enough to protect the brain from decline, especially if you are old.
The results were detailed in the journal Annals of Neurology February 10, 2025.
Vitamin B12: “healthy” but low levels linked to cognitive decline
To verify the role of vitamin B12 in the prevention of cognitive impairments, the researchers recruited 231 healthy participants without dementia or slight cognitive deficiency, whose average age was 71 years. Blood analyzes indicated that the average rate of vitamin B12 in the blood was on average 414.8 pmol/l, well above the recommended minimum of 148 pmol/l. Volunteers also passed cognitive tests during the experience.
The analyzes of the data collected revealed that people with a lower active vitamin B12 have shown a slower processing speed compared to those with higher concentrations of cobalamine. They also displayed significant delays in the response to visual stimuli. This indicates visual treatment speeds and a slower general cerebral conductivity than the others. The more the participants were elderly, the more the effect of a low rate on cognitive functions was marked.
“Healthy” but weak levels of vitamin B12 were also associated with a higher volume of lesions in the white substance, a sign of cognitive or dementia.
Vitamin B12 deficiency: rates should be redefined
Faced with their results, the researchers suggest reviewing the recommendations of B12 vitamins. “Previous studies which defined healthy quantities of vitamin B12 may have omitted to take into account subtle functional manifestations of high or low levels which can affect people without causing manifest symptoms”advance Dr. Ari J. Green, principal author of the study, in a press release. “Review the definition of vitamin B12 deficiency to integrate functional biomarkers could lead to earlier intervention and the prevention of cognitive decline.”
His colleague Alexandra Beaudry-Richard adds for his part: “In addition to redefining vitamin B12 deficiency, doctors should consider supplementation in elderly patients with neurological symptoms, even if their rates are within normal limits.”
