Vitamin K: The Overlooked Nutrient That Could Safeguard Your Memory

I recently came across a study that made me pause. It found that diets low in vitamin K might impair memory and speed up cognitive decline. In this research, mice fed a low-vitamin K diet had more trouble learning, remembering, and staying mentally sharp.

Now, before we get ahead of ourselves—it’s important to say this study was done in mice, not humans. But it does give us something to think about. Could a simple lack of vitamin K in our diets be quietly affecting how well we think and remember as we age?

Let’s look at what vitamin K does, where to find it, and whether increasing your intake might be worth considering.

What Is Vitamin K, and What Does It Do?

We usually think of vitamin K as the thing that helps your blood clot properly. And that’s true. But newer research shows it may also play a role in brain health, especially as we get older.

Vitamin K appears to:

• Protect brain cells from damage

• Help maintain blood flow to the brain

• Calm down inflammation (which can quietly wear down brain tissue over time)

And since the brain is so sensitive to inflammation, anything that helps keep things calm is worth noticing.

What the Study Showed

In the study, one group of mice was fed a normal diet, and another group had very little vitamin K. Over time, the low-vitamin K mice struggled with memory and learning tests. When scientists examined their brains, they found:

• Shrinkage in the area responsible for storing new memories

• Fewer new brain cells forming in that area

• Signs of inflammation in the brain

One of the researchers explained that this brain region—called the hippocampus—is also the first area affected in Alzheimer’s disease. So anything that protects it is worth looking at more closely.

Where Do We Get Vitamin K?

Vitamin K comes in two main types:

• Vitamin K1 – Found in green leafy vegetables like spinach, kale, broccoli, and lettuce

• Vitamin K2 – Found in fermented foods like sauerkraut, natto, aged cheeses, and also made by the good bacteria in your gut

To gently increase your intake:

• Add a handful of spinach or rocket to your lunch

• Toss some steamed broccoli on your dinner plate

• Try adding a small amount of fermented veg to a meal

If you’re taking blood thinners, it’s essential to talk to your doctor before making any changes. Vitamin K can affect how those medications work.

What We Don’t Know (Yet)

Now here’s the part I always want to include:This was an animal study. We can’t assume that what happens in mice will happen exactly the same way in humans. But it does give us clues.

The researchers believe that vitamin K may:

• Support memory by helping new brain cells grow

• Reduce inflammation, which protects against memory loss

Still, more human studies are needed before we can say for sure.

So, what should we do in the meantime?

Should You Try Getting More Vitamin K?

Here’s my take:As long as it’s not harmful, it’s okay to try gentle food-based changes. Adding a little more spinach to your meals or trying a few bites of fermented veg isn’t likely to hurt—and it may do a lot of good.

But always:

• Talk to your doctor or healthcare provider first

• Especially if you’re taking medications that interact with vitamin K (like warfarin)

• And avoid large supplement doses unless guided by a professional

A small nudge in the right direction can be a safe, helpful step—when it’s based on real food and common sense.

Final Thoughts

This study doesn’t give us all the answers, but it does offer a reminder:

Even lesser-known nutrients like vitamin K could play an important role in brain health.

You don’t need to go overboard. Just add a few more greens to your plate. Try something fermented now and then. And always make these changes with the guidance of your healthcare provider, who knows your history and what’s right for you.

Because keeping your brain healthy isn’t just about avoiding disease—it’s about staying clear, connected, and independent for years to come.

Evidence

1. Zheng T., et al. (2025). Low Vitamin K Intake Impairs Cognition, Neurogenesis, and Elevates Neuroinflammation in Mice. The Journal of Nutrition.

2. Medical News Today. (2025). Diets Low in Vitamin K May Impact Memory, Accelerate Cognitive Decline.

3. Harvard T.H. Chan School of Public Health. (n.d.). Vitamin K – The Nutrition Source.

4. Hess C. (2025). Commentary in Medical News Today on the impact of vitamin K on memory and the hippocampus.

5. Healthline Plus. (2025). The Emerging Role of Vitamin K in Brain Health.