Vitamin K
Vitamin K is essential for normal blood clotting and maintaining bone strength — often found in greens and fermented foods.
Vitamin K is a fat-soluble vitamin best known for its role in blood clotting. It helps activate proteins that allow blood to clot effectively and also contributes to bone mineralization, particularly in aging adults.
There are two primary forms: K1 (phylloquinone), found in leafy greens, and K2 (menaquinone), found in fermented foods like natto and in smaller amounts in meat and dairy. While deficiency is uncommon, it can lead to easy bruising, bleeding, or reduced bone density over time.
You can find vitamin K in kale, spinach, Brussels sprouts, and soybean oil. Because it's fat-soluble, pairing it with a healthy fat source improves absorption.
Recommended Daily Intake
- Women: 90 micrograms*
- Men: 120 micrograms*
- Upper Limit: Not known
Deficiency Symptoms
- A longer time for blood to clot or a prolonged prothrombin time (as measured in a physician’s office)
- Bleeding
- Hemorrhaging
- Osteopenia or osteoporosis
Common Food Sources
- Green leafy vegetables including collard and turnip greens, kale , spinach, broccoli, Brussels sprouts , cabbage, lettuces
- Soybean and canola oil
- Salad dressings made with soybean or canola oil
- Fortified meal replacement shakes
- Menaquinones Natto (fermented soybeans ) Smaller amounts in meat, cheese , eggs
- Natto (fermented soybeans )
- Smaller amounts in meat, cheese , eggs