What's the Difference: K1 and K2 What's the Difference: K1 and K2

Aug 28th 2018

What's the Difference: K1 and K2

Written by Laurel Sterling, MA, RD, CDN

Laurel is a registered dietitian-nutritionist and certified nutritionist and has worked in the natural products industry since 2000. She has a passion for empowering others through nutritional education.

Vitamin K is a fat-soluble vitamin group that includes vitamins K1 and K2. Recent research shows how important vitamin K is for people of all ages. What was once a vitamin recognized mainly for promoting healthy blood clotting is now understood to also promote bone and cardiovascular system health.

Vitamin K1 vs. K2

Vitamins K1 and K2 have slight variations in their chemical molecular structures and work slightly different in our body. K1, known as phylloquinone, is found primarily in green, leafy vegetables and is the most abundant form of vitamin K in our diet. It works to promote healthy blood coagulation, and supports strong bones. Our body converts the majority of K1 into K2.

Vitamin K2 is typically less abundant in our diet, as it's found in animal products and fermented soybeans. Vitamin K2 occurs in several forms; however, the two that appear to have the most biological activity are MK-4 (menatetrenon-4) and MK-7 (menaquinone-7).

MK-4 is more widely distributed in our body's tissues compared to other forms of K2. The MK-7 form is found to be better absorbed and to stay in the body longer. Most of the population, including adults and kids, can benefit from a vitamin K supplement, and especially those who eat little green, leafy vegetables or who have had their gallbladder or sections of their colon removed.

Vitamin K is valuable for the entire family. To help ensure you and your family get the nutrients needed for optimal cardiovascular, teeth, and bone health, consider adding vitamin K to your daily routine.