Vitamin B12 or cobalamin is a water-soluble vitamin essential for the normal functioning of the brain, the nervous system, and for the formation of blood and various proteins.
However, consuming it in excess has very pernicious effects, as it is deduced from a recent study published in JAMA Network Open .
Vitamin B12 can be found in foods like sardines and eggs. However, researchers at the University of Groningen in the Netherlands analyzed 5,571 Dutch men and women with an average age of approximately 54 years for approximately eight years , finding that those with higher levels of B12 in their blood plasma were more likely to to die earlier than those who had the lowest levels.
Specifically, their mortality rate was roughly double for those who took more B12.
The researchers even established that this connection was true after controlling for other factors such as age and a history of cancer and heart disease.
The reason behind these effects is unknown, but it may have something to do with how vitamin B12 affects gut bacteria .
This again reaffirms the idea that taking vitamin supplements not only has effects on people with a normal diet , but is counterproductive. For example, another 2019 study found that taking too much vitamin D was associated with an increased risk of premature death .