Vitamin K: The Forgotten Nutrient That Keeps You Strong and Protected

Vitamin K has long been known for its role in blood clotting, but recent research reveals a far more complex and vital role in our health. Especially in its K2 form, this vitamin is involved in keeping your bones strong, your arteries flexible, and your body’s calcium in the right places. It’s a nutrient most people have heard of, but few get enough of — and the consequences can remain invisible until disease strikes.

Vitamin K is not a single substance, but a group of fat-soluble compounds. The two most studied forms are K1 (phylloquinone) and K2 (menaquinones). Vitamin K1 is found mostly in green leafy vegetables and is used primarily by the liver to support blood clotting. Vitamin K2, on the other hand, is found in fermented foods, eggs, liver, grass-fed dairy, and meats. It plays a much more active role throughout the body, especially in bones, arteries, and soft tissues.

While Vitamin D helps you absorb calcium, Vitamin K2 helps guide that calcium into your bones and teeth — and away from your arteries. Without enough K2, calcium can accumulate in places where it doesn't belong, leading to arterial calcification and stiffening. This is a major risk factor for heart disease.

One of the most important proteins activated by Vitamin K2 is matrix Gla protein (MGP), which helps prevent calcium buildup in the arterial walls. Another is osteocalcin, which supports the integration of calcium into the bone matrix. Both of these proteins depend on sufficient Vitamin K2 to be activated and do their job.

In Japan, where natto (a fermented soybean food rich in K2) is commonly eaten, rates of bone fractures and arterial calcification are significantly lower compared to Western countries. Long-term studies show that regular intake of Vitamin K2 is associated with lower risks of osteoporosis, coronary heart disease, and even certain types of cancer.

Vitamin K2 also supports brain health. New findings suggest that it may help protect neurons and reduce oxidative stress in the brain, with possible implications for preventing neurodegenerative diseases. While more research is needed in this area, the initial evidence is promising.

Modern diets often fall short in Vitamin K2, especially in populations that avoid fermented foods, liver, or traditional animal fats. Industrial agriculture also plays a role — animals raised on grain-heavy diets produce less K2 in their milk, eggs, and meat than pasture-raised animals.

To support optimal Vitamin K intake:

Eat leafy greens daily for Vitamin K1. Include fermented foods like natto, miso, or raw sauerkraut. Choose grass-fed animal products, especially egg yolks, cheese, and butter. Don’t fear fat — Vitamin K is fat-soluble and best absorbed with healthy fats.

Vitamin K1 and K2 work together, but it’s K2 that often goes missing. The best strategy is to focus on real, minimally processed foods from trusted sources. At Real Food, we work closely with small-scale farmers who raise animals on pasture and produce fermented foods using traditional methods — giving your body what it truly needs to stay strong and protected.

For those on plant-based diets, it’s worth noting that K2 can be difficult to obtain without supplements unless fermented plant foods are consumed regularly. Miso, natto, and some aged soy sauces can help, though quantities vary widely.

The bottom line: Vitamin K is essential for calcium balance, bone integrity, cardiovascular protection, and possibly brain health. And yet, it’s often overlooked. By returning to natural, nutrient-rich foods, you can ensure your body gets what it needs — and avoid silent damage that may build over time.

Vitamin K might not get much attention, but it deserves a place at the center of any real food lifestyle.