As a dietitian, when I’m fighting a vitamin or mineral inadequacy, my first weapon of choice is food.
However, it can be hard to get enough of certain essential nutrients from an omnivorous diet (and possibly even harder if you’re vegan or vegetarian).
You may not have heard much about vitamin K2 before, it’s a form of vitamin K that plays a role in bone and heart health.
Together with vitamin D and calcium, vitamin K2 helps to prevent osteoporosis (1). It tells your body to deposit calcium into bones, rather than soft tissues like arteries. By directing plaque-forming calcium away from your blood vessels and organs, it’s associated with lower risks of blocked arteries (atherosclerosis) and heart disease (2).
Vitamin K2 can be obtained from dietary sources, such as natto, Japanese fermented soy beans, or liver. but your body can also convert vitamin K to vitamin K2 (3). Good sources of vitamin K are green leafy vegetables such as kale, spinach, Brussels sprouts, and Swiss chard. Dietary guidelines for vitamin K intake are as follows: 120 mcg for men 19+ and 90 mcg for women 19+ (4). There are currently no recommendations from Health Canada on how much vitamin K2 is needed for bone and heart health benefits.
Should you supplement vitamin K2? Based on the research evidence I found, I would consider K2 supplementation if you’re at risk for osteoporosis (be sure you’re getting enough vitamin D & calcium too). It may be helpful for certain populations like women undergoing menopause and the elderly. If you’re on anticoagulation therapy, drastically increasing your vitamin K intake may impact the effectiveness of the medication. For everyone else, follow Michael Pollan’s advice: eat food, not too much, mostly plants.
(1) Knapen, M. H., Schurgers, L. J., & Vermeer, C. (2007, July). Vitamin K2 supplementation improves hip bone geometry and bone strength indices in postmenopausal women. Osteoporosis International, 18(7), 963-972. doi:10.1007/s00198-007-0337-9
(2) Geleijnse, J. M., Vermeer, C., Grobbee, D. E., Schurgers, L. J., Knapen, M. H., Van der Meer, I. M., Witteman, J. C. (2004, November 1). Dietary Intake of Menaquinone Is Associated with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study. The Journal of Nutrition, 134(11), 3100-3105.
(3) Vitamin K — Health Professional Fact Sheet. (n.d.). Retrieved November 23, 2016, from https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
(4) Dietary Reference Intakes. (2010). Retrieved November 23, 2016, from http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/ref_vitam_tbl-eng.php