Vitamin K, often overlooked, may play a bigger role in brain health than we thought. A new study in The Journal of Nutrition looked at what happens when mice don’t get enough of this vitamin in their diet—and the results were eye-opening.
Mice given a low vitamin K diet showed lower levels of vitamin K in their brains and performed worse on memory and learning tasks. In contrast, mice on a normal diet didn’t have these problems. This suggests vitamin K might be important for keeping the brain working properly.
Can Low Vitamin K Lead to Memory Loss?
Researchers believe that a lack of vitamin K could speed up age-related memory decline. To test this, they fed middle-aged male and female mice either a low-vitamin K diet or a normal diet for six months, according to MedicalNewsToday.
They ran behavior tests to check how well the mice could learn and remember things. One of these tests was “novel object recognition”—smart mice are expected to explore a new object they’ve never seen. Another test was the Morris water maze, where mice had to find a hidden platform in water using memory.
After the tests, researchers also checked vitamin K levels in the brain, liver, and kidneys and looked at changes in brain tissue.
What the Study Found
The mice on the low vitamin K diet had worse results. Male mice in this group didn’t live as long and didn’t gain as much weight as the others. Female mice didn’t show these physical changes, but they still had brain-related issues.
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These mice had less menaquinone-4 (MK4), the main type of vitamin K found in the brain. Their liver and kidney vitamin K levels were also lower.
In memory tests, the vitamin K–K-deficient mice didn’t explore new objects as much—suggesting their memory was weaker. They also took longer to find the platform in the water maze, especially in the early days.
How Vitamin K Affects the Brain
Researchers found that mice with low vitamin K had changes in the hippocampus, the part of the brain linked to learning and memory. These mice had fewer new brain cells forming in this area—a process called neurogenesis.
Dr. David Hess, a brain expert not involved in the study, explained that the hippocampus is one of the few brain areas where new neurons are made in adults. It’s also the part that’s affected early in Alzheimer’s disease, as per MedicalNewsToday.
The low vitamin K mice also had more active microglial cells—cells that respond to brain damage or infection. This showed signs of more inflammation in their brains.
These results suggest vitamin K might help protect the brain by reducing inflammation and supporting the growth of new neurons.
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What This Means for Humans
Even though the study was done in mice, it raises important questions. Can vitamin K affect brain health in people, too?
There were some limits to the study. Fewer male mice were available for testing by the end because more of them died on the low vitamin K diet. That affected the final data. Also, the researchers only studied one type of vitamin K found in human diets.
They couldn’t measure certain proteins and enzymes that depend on vitamin K due to the small amount of brain tissue available. These may help explain why vitamin K affects brain function.
It’s also unclear how the length of time without vitamin K or the age of the mice affects the results. There were also differences between male and female mice that need more research, as highlighted by MedicalNewsToday.
Dr. Ryan Hakimi, a brain specialist not involved in the study, said the findings are a good reminder about the importance of a healthy diet. He suggested that doctors might want to talk to patients—especially those with a family history of dementia—about getting enough vitamin K through food.
Final Thoughts
This study shows that vitamin K might do more than help with blood clotting—it could also play a key role in memory, learning, and brain health. While more studies are needed on humans, making sure we get enough vitamin K could be one simple way to support our brains as we age.
