Most athletes are familiar with the importance of Vitamin D, calcium, and magnesium for bone strength and performance. But there’s another nutrient often overlooked: Vitamin K.
Far beyond its role in blood clotting, Vitamin K contributes to stronger bones, healthier joints, better circulation, and even reduced risk of injuries.
This article dives deep into everything you need to know about Vitamin K: its types, health benefits, impact on athletic performance, natural sources, and how to ensure you’re getting enough.

What is Vitamin K?
Vitamin K is a fat-soluble vitamin divided into two main types:
- Vitamin K1 (phylloquinone): found mainly in green leafy vegetables.
- Vitamin K2 (menaquinone): found in animal-based and fermented foods like cheese, liver, and natto (fermented soybeans).
Together, they play a critical role in:
- Blood clotting.
- Directing calcium to the bones and teeth instead of the arteries.
General Health Benefits of Vitamin K
- Bone Strength
- Activates osteocalcin, a protein that binds calcium to bones.
- Reduces the risk of osteoporosis and fractures.
- Heart Health
- Prevents arterial calcification by controlling calcium deposits.
- Supports flexible, healthy blood vessels.
- Wound Healing
- Essential for blood clotting, speeding up recovery from cuts or small injuries.
Vitamin K and Athletic Performance
- Reduced Risk of Injuries: Higher bone density lowers the chance of stress fractures.
- Joint and Cartilage Support: Plays a role in calcium metabolism.
- Improved Circulation: Enhances oxygen and nutrient delivery to muscles.
- Indirect Muscle Recovery: Helps reduce inflammation and supports tissue health.
Top Food Sources of Vitamin K
Food Source | Type | Approx. Content (µg per serving) |
---|---|---|
Spinach (cooked) | K1 | 145 |
Kale (cooked) | K1 | 500+ |
Broccoli (cooked) | K1 | 90 |
Cabbage | K1 | 160 |
Hard Cheese | K2 | 50–75 |
Animal Liver | K2 | 60–70 |
Natto (fermented soy) | K2 | 1000+ (highest source) |
Daily Requirements for Athletes
- Adult men: ~120 µg/day.
- Adult women: ~90 µg/day.
- Athletes: No official higher recommendation, but maintaining balance with Vitamin D and calcium is key for bone and joint health.
Signs of Vitamin K Deficiency
- Weak or fragile bones.
- Easy bruising or frequent bleeding.
- Slow recovery from injuries.
- Increased risk of arterial calcification.
Do You Need Vitamin K Supplements?
- Most people meet their needs through diet.
- Vegetarians/vegans may need extra K2 since it’s mainly in animal foods.
- Supplements often combine Vitamin D3 + K2, a powerful combo for bone and heart health.
Important: If you’re on blood thinners (e.g., warfarin), always consult your doctor before supplementing.
FAQs
Does Vitamin K directly increase strength?
No, but it supports bones and joints, allowing consistent training without injuries.
Should I take it with Vitamin D?
Yes. Vitamin D boosts calcium absorption, while K directs calcium into bones.
Can you overdose on Vitamin K?
Unlikely from food sources; with supplements, stick to recommended doses.
Conclusion
Vitamin K might be the “forgotten player” in sports nutrition, but it’s essential for long-term health and performance. From protecting bones and joints to improving circulation, it ensures your body can handle tough training.
Practical tip:
- Eat leafy greens daily.
- Add fermented foods or cheese for K2.
- Consider a combined Vitamin D3 + K2 supplement if your diet is lacking.
By making Vitamin K a priority, you’ll not only improve your health but also unlock better athletic performance.
Athlete, blogger, and fitness content creator. Currently studying to become a certified nutrition specialist, with over 6 years of consistent training experience. I have explored various sports disciplines, from kickboxing to running, cycling, and powerlifting, eventually committing fully to resistance training.
I founded FitspotX after noticing the overwhelming amount of misleading information in the fitness and nutrition space, especially in written content. My vision was to create an all-in-one platform that combines practical tools with simple, science-based content—helping you better understand nutrition and confidently achieve your fitness goals.