Vitamin K is a fat-soluble vitamin that plays an essential role in blood clotting and bone health. It was discovered in the 1930s and is named after the German word “Koagulationsvitamin,” which means clotting vitamin. There are two primary forms of vitamin K: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone). Vitamin K1 is found in green leafy vegetables, while vitamin K2 is produced by bacteria in the gut and can also be found in animal products.
Vitamin K and Blood Clotting
One of the most important functions of vitamin K is its role in blood clotting. When a blood vessel is damaged, platelets come together to form a plug, and a series of chemical reactions occur to form a clot. Vitamin K is necessary for the activation of several proteins involved in blood clotting, including prothrombin, factor VII, IX, and X.
People who do not get enough vitamin K may experience bleeding problems, such as nosebleeds, bleeding gums, or easy bruising. However, people who take blood thinners, such as warfarin, may need to limit their intake of vitamin K because it can interfere with the medication’s effectiveness.
Vitamin K and Bone Health
Vitamin K is also important for bone health. It helps to activate a protein called osteocalcin, which is necessary for bone mineralization. In other words, without enough vitamin K, the body may not be able to properly use calcium to build strong bones.
Studies have shown that people who consume more vitamin K have a lower risk of hip fractures and osteoporosis. One study followed over 72,000 women for 10 years and found that those who consumed the most vitamin K had a 30% lower risk of hip fractures than those who consumed the least.
Food Sources of Vitamin K
The best food sources of vitamin K1 are green leafy vegetables, such as kale, spinach, collard greens, and broccoli. Other good sources include Brussels sprouts, asparagus, and green beans. One cup of cooked kale provides over 1000% of the daily recommended intake of vitamin K1.
Vitamin K2 is found in fermented foods, such as cheese, sauerkraut, and natto, as well as in animal products, such as egg yolks, liver, and chicken. The bacteria in the gut also produce small amounts of vitamin K2.
Vitamin K Deficiency
Vitamin K deficiency is rare in healthy adults because the body can store it in the liver for several weeks. However, people with certain medical conditions, such as liver disease or cystic fibrosis, may be at higher risk of deficiency. Newborn infants are also at risk because they do not yet have the bacteria in their gut to produce vitamin K2.
Symptoms of vitamin K deficiency can include bleeding problems, such as nosebleeds, bruising, or bleeding gums. In severe cases, it can lead to hemorrhage, which is excessive bleeding that can be life-threatening.
Supplements and Safety
Most people can get enough vitamin K through their diet and do not need to take supplements. However, people who are at risk of deficiency or who have a medical condition that affects vitamin K absorption may benefit from supplements.
The recommended daily intake of vitamin K for adults is 90 mcg for women and 120 mcg for men. There is no upper limit for vitamin K because it is non-toxic, but people taking blood thinners should talk to their doctor before taking supplements.
Final Thoughts
Vitamin K is an essential nutrient for blood clotting and bone health. It is found in green leafy vegetables, fermented foods, and animal products. Most people can meet their daily needs through their diet, but those at risk of deficiency or with certain medical conditions may need supplements. If you are unsure about your vitamin K status or have concerns about your intake, it is always a good idea to consult with a healthcare professional. By ensuring that you are getting enough vitamin K, you can help support your overall health and well-being.meet their daily needs through their diet, but those at risk of deficiency or with certain medical conditions may need supplements. If you are unsure about your vitamin K status or have concerns about your intake, it is always a good idea to consult with a healthcare professional. By ensuring that you are getting enough vitamin K, you can help support your overall health and well-being.
