Higher dietary intake of vitamin K1, commonly found in leafy green vegetables, is associated with a 16% lower likelihood of chronic obstructive pulmonary disease (COPD), according to a study by researchers at Edith Cowan University. Published in The American Journal of Clinical Nutrition, the observational study of 179,062 participants suggests that vitamin K1 may support lung function by activating proteins that maintain tissue flexibility.
How Vitamin K1 Impacts Respiratory Health
Researchers at Edith Cowan University examined the link between dietary vitamin K and chronic respiratory conditions, including COPD and asthma. The study, which tracked participants over a 10-and-a-half-year period, found that increased consumption of vitamin K1—the primary form of the nutrient found in vegetables—correlated with better overall lung function.
Associate Professor Marc Sim, who was involved in the study, noted that vitamin K likely activates specific proteins that help keep lung tissue flexible and prevent damage. While the study established a correlation, it did not prove a direct causal link, as the research was observational. The protective effects were notably more pronounced in smokers and individuals working in high-risk occupations, according to the findings.
While vitamin K1 is linked to lung health, the study found no association between either vitamin K1 or K2 and the prevention of asthma. Additionally, vitamin K2, which is found in fermented foods and dairy, did not show a statistical reduction in COPD rates.
Simple Ways to Increase Vitamin K1 Intake
Boosting vitamin K1 levels can be as simple as adding one extra serving of leafy greens to a daily diet, according to study researcher Chengfeng Li. These vegetables are nutrient-dense.
Common sources of vitamin K1 include:
- Spinach
- Kale
- Broccoli
- Collard greens
- Swiss chard
- Brussels sprouts
- Turnip greens
Why Prevention Matters for Chronic Respiratory Disease
Chronic respiratory diseases remain a significant global health challenge. Data reported in the study indicates that these conditions were the third leading cause of death in 2019, impacting approximately 454.6 million people and accounting for 4 million deaths worldwide.
The Mayo Clinic identifies smoking as the leading cause of COPD, though exposure to environmental irritants—such as dust, chemicals, and pollution—also contributes to the disease. Because conditions like asthma and COPD are currently considered incurable, researchers emphasize that identifying effective dietary prevention strategies is a critical step.
Pro Tip: Maximize Nutrient Absorption
Vitamin K is a fat-soluble vitamin.
Frequently Asked Questions
Can vitamin K supplements replace a healthy diet?
The study specifically focused on dietary intake of vitamin K1 through food. Researchers like Chengfeng Li emphasize that increasing servings of leafy greens is an achievable way to boost intake naturally.
Is there a difference between vitamin K1 and K2?
Yes. Vitamin K1 is primarily found in vegetables and is linked to blood clotting and, as this study suggests, lung function. Vitamin K2 is found in fermented foods, certain dairy products, eggs and meats, and is primarily known for supporting bone health and regulating calcium in the body.
Does this study prove that vitamin K prevents COPD?
No. Because this was an observational study, it demonstrates an association between higher intake and lower risk, but it does not confirm that vitamin K1 directly causes the reduction in COPD rates.
Are you looking to improve your nutritional habits? Share your favorite ways to incorporate more leafy greens into your meals in the comments below, or subscribe to our lifestyle newsletter for more health-focused updates.
