As the global population ages, understanding the role of nutrition in preserving brain function is more critical than ever. A new study published in The Journal of Nutrition (DOI: 10.1016/j.tjnut.2025.01.023) provides compelling evidence that low intake of vitamin K could accelerate age-related memory decline, highlighting the essential role this vitamin plays in supporting cognitive resilience.
Conducted by scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University, the research offers biological and behavioral insights into how a vitamin K-deficient diet can impair memory and learning—especially during the aging process.
🧪 The Study: How Low Vitamin K Affects the Aging Brain
In this controlled study, middle-aged mice were divided into two groups over six months:
One received a vitamin K-adequate diet.
The other received a vitamin K-deficient diet.
The focus was on menaquinone-4 (MK-4), a brain-active form of vitamin K2 that is particularly abundant in neural tissue. Researchers found that mice on the vitamin K-deficient diet had markedly lower MK-4 levels in their brains, especially in regions associated with memory such as the hippocampus.
Behavioral tests revealed:
Reduced performance in spatial memory tasks.
Impaired learning efficiency.
Diminished exploratory behavior—an early cognitive indicator.
These results suggest that insufficient vitamin K intake may directly contribute to neurodegenerative processes linked to memory loss.
🔬 What’s Happening in the Brain?
The study went beyond behavioral testing to analyze molecular and structural changes in the brain.
Key findings included:
A reduction in neurogenesis (birth of new neurons) in the hippocampus.
An increase in activated microglia, indicating elevated neuroinflammation.
Disruption of calcium-binding proteins involved in neural signaling, which are vitamin K-dependent.
These biological changes are known to underlie cognitive decline and are commonly observed in conditions like Alzheimer's disease and vascular dementia.
🥬 Why Vitamin K Is Crucial for Cognitive Function
Vitamin K exists in two main forms:
Phylloquinone (Vitamin K1) – Found in leafy greens (spinach, kale, collards).
Menaquinones (Vitamin K2) – Found in fermented foods, eggs, cheese, and meat.
While traditionally known for its role in blood clotting, vitamin K has increasingly been recognized for its neuroprotective effects, including:
Supporting sphingolipid synthesis, essential for neuronal membrane integrity.
Modulating oxidative stress and inflammation.
Enhancing activity of vitamin K-dependent proteins like Gas6, which support neural survival and synaptic plasticity.
👵 What This Means for Aging Adults
This study adds weight to a growing body of literature suggesting that adequate vitamin K intake can slow cognitive decline. Although conducted in mice, the mechanisms observed—neuroinflammation, reduced neurogenesis, and impaired memory—mirror patterns seen in human cognitive aging.
Epidemiological studies in humans have already linked low plasma vitamin K to:
Poorer verbal memory
Increased risk of Alzheimer’s and dementia
Reduced brain volume in aging adults
Maintaining optimal levels of vitamin K may not only support physical health but also act as a nutritional safeguard for brain longevity.
🍽️ How to Get More Vitamin K Naturally
The National Institutes of Health recommends:
120 mcg/day for adult men
90 mcg/day for adult women
Top dietary sources include:
Vitamin K1 (phylloquinone): Kale, spinach, broccoli, romaine lettuce, parsley.
Vitamin K2 (menaquinone): Natto (fermented soybeans), hard cheeses, egg yolks, chicken, and liver.
If you're considering supplementation, be sure to consult with a healthcare provider—especially if you are on blood-thinning medication, as vitamin K can interact with anticoagulants like warfarin.
🔎 What’s Next in Research?
Future studies will need to:
Confirm the same neurological effects in human clinical trials.
Determine if supplementation or diet changes in older adults can reverse or slow cognitive decline once it has begun.
Explore whether vitamin K works synergistically with other brain-friendly nutrients like omega-3s, vitamin D, and B vitamins.
The findings reinforce the idea that nutrition is not just about fueling the body—it shapes the health of the mind as well.
🧠 Final Thoughts
This research marks a critical advancement in our understanding of the diet-brain connection. By establishing a mechanistic link between low vitamin K levels and memory decline, it empowers individuals—and healthcare providers—to take proactive steps through diet to support cognitive health.
Eating more leafy greens might be one of the simplest, most accessible things we can do to protect our brains as we age.
📖 Source:
Low Vitamin K Intake May Accelerate Age-Related Memory Decline,
The Journal of Nutrition, 2025.
Read the full study →
