Vitamin K1 vs K2: a side-by-side comparison

Vitamin K1 vs K2

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.)	Helps direct calcium to the right places (into bones and teeth and out of soft issues like arteries and kidneys) May help support bone, heart and brain health.
Found in	Green leafy vegetables	Fermented foods (some European hard cheeses and Natto or fermented soybeans) Fatty organ meats like liver Chicken dark meat Some pork products Egg yolks from pastured chicken Grass-fed butter
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.	Common
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	Bruises Increased bleeding time Small blood clots under nails Increased bleeding in mucous membranes.	Weak bones Increased plaque deposits along gumline Increase in cavities Arterial calcification
Causes of deficiency	Lack of green leafy vegetables in diet Anticoagulant medications (Warfarin/Coumadin) Antibiotics Fat malabsorption disorders.	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	Moderate
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?	Vitamin K1 travels to liver more effectively than to bones. Liver uses Vitamin K1 to activate proteins needed for blood clotting.	Vitamin K2 travels to bone more effectively than K1. Bones use K2 to produce Osteocalcin, a bone-building protein hormone, which also supports metabolic health. The MK-4 form of Vitamin K2 is effective at reaching tissues other than liver and bones. The MK-7 form of K2 is 3X better at reaching bones and activating Osteocalcin than K1.
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.

The Prevalence of VitaminK Deficiency/Insufficiency, and Recommendations for Increased Intake.

Metabolism and cell biology of vitamin K.

Vitamin K–containing dietary supplements: comparison of synthetic vitamin K₁ and natto-derived menaquinone-7.

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.

DISCLAIMER
This website is for educational and informational purposes only. The ideas, opinions and suggestions contained on this website are not to be construed as medical advice. If you have, or suspect you may have, a medical condition you should seek advice from a licensed health care practitioner. Readers of this website should not rely on the information provided or contained herein as a substitute for medical advice, diagnosis or treatment from your doctor for any health condition or problem. Users of this website should not rely on information provided on this website for their own health problems. Any questions or concerns regarding your own health should be addressed to your own physician. You should not start or stop any medications, diet or exercise plan without first consulting with your doctor. We neither encourage you to do so, nor are we liable for the failure to seek medical advice from the appropriate licensed medical health practitioner.

We are here
to help.

Vitamin K1 vs K2: a side-by-side comparison

Side-by-side comparison of Vitamin K1 and K2:

Vitamin K1

Vitamin K2

Name

What does it do?

Found in

Contained in multivitamins?

Fat-soluble

Deficiency

Daily Value (RDA)

Toxicity

Deficiency symptoms

Causes of deficiency

Circulation in blood

Effect on bone health

Effect on heart health

Present in brain

What happens after consumption?

Effect on gene expression

Interferes with function of blood thinning medications

Dietary contribution to Vitamin K activity

References:

Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health.

The Prevalence of VitaminK Deficiency/Insufficiency, and Recommendations for Increased Intake.

Metabolism and cell biology of vitamin K.

Vitamin K–containing dietary supplements: comparison of synthetic vitamin K₁ and natto-derived menaquinone-7.

Get Inspired