Learning about Vitamin K

You’ve heard about vitamins A, B, C, D, and E – but what aboutvitamin K?  After we skip over some unused letters of the alphabet, vitamin K is where we land.  This vitamin in known to play a significant role in helping the blood clot, and was named after the German word for blood clotting – koagulation (Aha! That’s where the K comes from!)   Proper blood clotting is important in preventing excessive bleeding when facing cuts,scrapes or any other skin punctures. Blood clotting is a complex process, where many proteins are involved – these proteins need vitamin K to do their job right.  

Vitamin K is made up of a group of three different compounds, or three basic types of vitamin K. These can aptly be referred to as vitamins K1, K2, and K3.  K1 is the form of vitamin K found in plant foods, like leafy greens and vegetables. Vitamin K2 is obtained from meats, eggs, cheeses, and synthesized by bacteria. K2 can also be found in fermented foods like miso or tempeh (soy products). K2 has been making headlines recently, as more research has pointed to its role in regulating calcium distribution.  The data is still preliminary, but it seems that vitamin K2 may help prevent heart disease, improve bone health and lower the risk of osteoporosis. Thus far, vitamin K3 has remained a bit of a mystery and only trace amounts have been found in foods.


Unlike the other vitamins mentioned or that you’ve heard of, vitamin K is different in that it is not usually recommended as a dietary supplement. Having low levels of vitamin K can equate to uncontrolled bleeding, but this deficiency is pretty rare in adults.   Infants on the other hand are commonly diagnosed with vitamin K deficiency, which is resolved by an injection of the vitamin. For those taking blood thinners like Coumadin, Vitamin K can be used to counteract an overdose and balance clotting factors.

While uncommon, you could be may be at higher risk for this vitamin deficiency if:

• You have Crohn's or Celiac disease 

• You are severely malnourished

• You drink alcohol heavily

• You take medication that interferes with absorption of the vitamin

In these cases, your doctor might recommend vitamin K supplements. Vitamin K1 is the main form supplement availablehere in the US. There are risks involved however when taking this supplement, especially for those with diabetes, kidney or liver disease.  The supplements can lower blood sugar levels, or worsen clotting problems.

Of course, you don’t need to take a supplement to get your vitamin K.  You can get vitamin K naturally from the foods you eat.  Generally green vegetables and leafy greens are good sources of vitamin K.  Some sources of the vitamin include:

• Vegetables like spinach, asparagus, and broccoli

• Dark leafy greens like kale

• Beans and soybeans

• Eggs

• Strawberries

• Meat