Until recently, when we talked about Vitamin K, we meant K1.
When multivitamins say 'Vitamin K' on the label, they mean K1. It's needed for proper blood clotting. Newborns are given a shot of K1 to prevent excessive bleeding.
Things have changed in the last 10 years. We know a LOT more about Vitamin K2 and its effect on health.
Vitamin K1 and K2 are similar, but they're not the same.
Side-by-side comparison of Vitamin K1 and K2:
Vitamin K1 |
Vitamin K2 |
|
---|---|---|
Name |
Phylloquinone (single substance) |
Menaquinone (a family of similar molecules called MK, from MK-4 to MK-13. MK-4 is the type most often consumed in food.) |
What does it do? |
Blood clotting - prevents excessive bleeding. (K1 is what prevents a paper cut from becoming dangerous.) |
|
Found in |
Green leafy vegetables |
|
Contained in multivitamins? |
Yes |
No |
Fat-soluble |
Yes, best if eaten with some fat |
Yes, best if eaten with some fat |
Deficiency |
Rare, except in newborns. |
|
Daily Value (RDA) |
90 micrograms for women 120 micrograms for men |
Not yet established, but experts recommend 100 to 200 micrograms of K2 daily. |
Toxicity |
No known toxicity if taken at recommended levels. |
No known toxicity if taken at recommended levels. |
Deficiency symptoms |
|
|
Causes of deficiency |
|
Lack of fermented foods and organ meats in diet. |
Circulation in blood |
Brief (hours) |
Prolonged (days). Due to Vitamin K2's longer molecule, it is transported by different carriers in the blood than K1 and therefore, to different locations in the body. |
Effect on bone health |
Minimal |
|
Effect on heart health |
Minimal | Moderate |
Present in brain |
No |
Yes. The MK-4 form of Vitamin K2 is the predominant form found in the brain, but we don't yet know what it does there. |
What happens after consumption? |
|
|
Effect on gene expression |
No known influence on gene expression. |
MK-4 form of Vitamin K2 shows some influence on gene expression. |
Interferes with function of blood thinning medications |
Yes. Anti-coagulant medications work by creating an artificial Vitamin K deficiency. |
Yes. Vitamin K2 can also interfere with the blood thinning medications. Talk to your doctor before using Vitamin K2 supplements if you are taking Warfarin or other similar drugs. |
Dietary contribution to Vitamin K activity |
Major. Close to 90% of Vitamin K in western diets is from Vitamin K1. |
K2 as MK-4: minor as a direct dietary source of Vitamin K. K2 as MK-7: minor as a direct dietary source of Vitamin K As MK-10 to MK-13: minor. |
References:
Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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