Like most supplements, not all are created equally. When looking closer at vitamin K, that holds true. There is no official recommended daily intake of vitamin K for a healthy person, but we do require it and likely somewhere between 100µm to 200µg per day is a good target to aim for.
It’s important knowing there are two forms – K1 and K2. Vitamin K1, also called phylloquinone, is used in our liver to make the proteins involved in blood clotting whereas Vitamin K2, also called menaquinone, works synergistically with vitamin D and calcium (and other nutrients) by helping to move calcium into the proper areas in your body, such as your teeth and bones.
Vitamin K2 occurs in several forms, each of which is designated by the length of the side chain. So MK4 is shorter than MK7 by three lengths. Between the two, MK7 has a longer half-life, meaning it stays around in your body longer. Between the two there is some debate as to which is more effective or which is more researched. MK4 has been shown to reduce fracture incidence in post-menopausal women with osteoporosis whereas in another study MK7 has been found to significantly increase serum MK7 levels where MK4 failed to increase MK4 values. It may be that MK7 is most effective at reaching liver and bone tissue and MK4 is more effective at reaching most other tissue, thus making it better at protecting those tissues from developing cancer, calcium deposits, and by supporting sex hormone production. A limitation of this research might be in looking at mono-therapies – these vitamins work in synergy among themselves and with various cofactors. It isn’t just as simple as take this one form of this one vitamin to improve this one thing. We are far more complex than that.
So reflect on what you’re eating – K1 in leafy greens, MK4 in animal foods, and MK7 in fermented foods – where are you getting these forms of K? Are these areas of your nutrition that need more attention? There are certainly times to supplement, but my hope for most is they are eating a diverse enough diet regularly that supplementation isn’t necessary…but when it is, pair fat soluble vitamins (A, E, D, and K) with eating good healthy fats to improve absorption.
Dr. Brian Myers is a naturopathic primary care doctor with a focus on pediatric and family health at Live Well Clinic in La Quinta. For more information regarding how you can eat healthier and live a more natural lifestyle, call us at 760-771-5970.