Why Your Body Needs Vitamin K: Bone Strength, Blood Health, and More

It started with a stumble.
Margot, a 63-year-old retired ballet teacher, was watering her garden one morning when she slipped on a wet patio tile. The fall was gentle, but the pain in her wrist wasn’t. An X-ray confirmed it—a small fracture. Her doctor, after reviewing her bone scans, asked something she hadn’t heard before: “How’s your vitamin K intake?”

Margot blinked. “Vitamin what now?”

While we all know about calcium and vitamin D for bone strength, vitamin K is the unsung hero in the orchestra of bone, heart, and blood health. It works quietly in the background—helping proteins bind calcium, supporting vascular elasticity, and aiding in blood clotting. Yet many people don’t even know it exists, much less why small amounts of it can mean big results.

Let’s break down what science has to say about vitamin K supplementation, how much you really need, and why this fat-soluble vitamin deserves a spot on your daily health radar.

What Is Vitamin K?

Vitamin K isn’t just one compound—it’s a family. The two most researched forms are:

• Vitamin K1 (phylloquinone) – Found in green leafy vegetables, such as kale, spinach, and broccoli.

• Vitamin K2 (menaquinone) – Found in fermented foods, animal products, and supplements, such as MK-7, the more bioavailable and longer-lasting form.

Vitamin K helps activate matrix Gla protein (MGP) and osteocalcin, which are responsible for regulating calcium in bones and arteries. Without vitamin K, these proteins are inactive—leading to potential bone fractures, arterial stiffness, or even heart disease.

Blood Health: Beyond Clotting

One of the earliest known roles of vitamin K was in supporting blood clotting, which is why people on blood thinners (like warfarin) are often told to monitor their intake. But beyond that, vitamin K supports blood vessel elasticity, helping prevent calcium buildup in arteries.

A study suggested that people with adequate intakes (AIs) of vitamin K2 had a significantly lower risk of vascular calcification. Think of it as nature’s traffic controller—guiding calcium to bones instead of letting it clog your arteries.

Bone Health: The Calcium Connection

Bones may seem rigid, but they are biologically active tissue, constantly breaking down and rebuilding. Vitamin K2, particularly the MK-7 form, plays a central role in this regeneration process.

• It activates osteocalcin, which helps bind calcium to the bone matrix.

• Without it, even if you consume enough calcium and vitamin D, your body may not properly utilize them.

• Research has shown that low levels of vitamin K are associated with increased risk of bone fractures, especially in postmenopausal women.

For people over 50, or those dealing with osteopenia, including vitamin K supplementation in their routine could be game-changing.

Heart and Brain: The Emerging Benefits

Vitamin K’s benefits may extend beyond bones and blood. New research is exploring its role in supporting the brain, heart, pancreas, and bone as interconnected systems.

• In the brain, vitamin K is involved in the metabolism of sphingolipids, which help maintain cell membranes and may protect against age-related cognitive decline.

• In the heart, its role in keeping calcium away from arteries may reduce the risk of atherosclerosis.

• And while more studies are needed, early findings show vitamin K may also support pancreatic insulin regulation.

Are You Getting Enough?

The Recommended Dietary Allowance (RDA) for vitamin K varies by age and gender:

Group	RDA (mcg/day)
Adult Men	120
Adult Women	90
Pregnant Women	90

However, these numbers only reflect what’s needed to prevent deficiency—not necessarily to optimize health.

With modern diets shifting away from traditional sources like fermented foods and leafy greens, many people fall short of adequate intakes of vitamin K, especially K2.

Sources of Vitamin K

1. Vitamin K1-rich foods:

   • Kale

   • Spinach

   • Broccoli

   • Collard greens

2. Vitamin K2-rich foods:

   • Natto (fermented soybeans)

   • Cheese (especially hard varieties)

   • Egg yolks

   • Chicken liver

3. Supplements:

   • For those who struggle with consistent dietary intake or need a targeted boost, vitamin K2 MK-7 supplements are a reliable option.

Is Supplementation Safe?

Generally, yes—especially for healthy adults.

• Vitamin K is fat-soluble, so it’s best taken with meals that contain healthy fats.

• There are no known toxic effects of high doses of vitamin K1 or K2.

• However, those on blood thinners should consult their doctor before adding any form of vitamin K, as it can interfere with medication.

Our Recommended Pick

For a high-quality, naturally sourced option, check out:
👉 Solgar Naturally Sourced Vitamin K2 (MK-7), 100 mcg, 50 Vegetable Capsules

• Supports bone strength

• Helps regulate calcium metabolism

• Easy-to-absorb MK-7 form

• Vegetarian-friendly capsules

Small Vitamin, Big Impact

Vitamin K might not get as much press as vitamin C or D, but it plays critical roles in your body’s silent systems—your blood vessels, bones, and even your brain. If you're focusing on long-term vitality, this is one nutrient you don’t want to ignore.

Whether it’s increasing your leafy green intake, indulging in a little natto (if you’re adventurous), or choosing a trusted supplement, give your body the K it quietly craves.