Vitamin K

Vitamin K produces many of the proteins necessary for blood clotting.¹ Some research suggests it could also be important for strong bones, but so far the results are inconclusive.²

There are many types of vitamin K, but the two major types in the human diet are phylloquinones (vitamin K1), which are made by plants, and menaquinones (vitamin K2), which are made by bacteria in the intestines. It is estimated that these bacteria produce about half of the vitamin K the body needs daily.³ For this reason, and because new research suggests vitamin K1 and vitamin K2 may have different functions in the body⁴, it is important to eat a wide variety of foods with vitamin K.

Men are recommended 120 mcg vitamin K daily. Women should aim for 90 mcg.⁵

Vitamin K is found in leafy greens, such as kale, spinach, and romaine lettuce. It is also found in herbs, such as parsley, basil, thyme, and sage, as well as in vegetables like Brussels sprouts, broccoli, celery, and cucumber. Smaller quantities of vitamin K are also found in meat, fish, and eggs.⁶

Vitamin K deficiency is most likely in people suffering from conditions that negatively impact digestion, or after long-term antibiotic use, which can damage the good bacteria in the intestines. If you have a vitamin K deficiency, you may bruise easily and notice gum bleeding, nosebleeds, etc.²

Vitamin K-rich Foods

Sources

1. Harvard School of Public Health Nutrition Source - Vitamin K
2. The Linus Pauling Institute Micronutrient Information Center - Vitamin K
3. American Cancer Society - Vitamin K
4. Journal of Agricultural and Food Chemistry - Vitamin K Contents of Meat, Dairy, and Fast Food in the U.S. Diet
5. University of Maryland Medical Center - Vitamin K
6. MedlinePlus - Vitamin K