Walnuts are not a primary vitamin K source, though nuts can contribute small amounts. Walnuts are better known for ALA (an omega-3 precursor), polyphenols, and being energy-dense. In a vitamin K-focused diet, walnuts play a supportive role; leafy greens and certain fermented foods are far more impactful. For people on anticoagulants, walnuts matter more for overall diet consistency than for vitamin K specifically. In short, walnuts can be a heart-healthy choice but are not a major vitamin K “powerhouse.”