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Vitamin K2 Disease Interactions

There is 1 disease interaction with Vitamin K2 (menaquinone).


Phytonadione (vit. K) (applies to Vitamin K2) hepatobiliary dysfunction

Moderate Potential Hazard, Moderate plausibility. Applicable conditions: Biliary Obstruction, Liver Disease

Phytonadione is fat soluble and requires bile for adequate intestinal absorption. Biliary dysfunction decreases the absorption of phytonadione. Phytonadione is metabolized by the liver and excreted in bile and urine. Hepatic and/or biliary impairment can alter the metabolic and therapeutic activity of phytonadione. Phytonadione will not correct hypoprothrombinemia due to hepatocellular dysfunction or damage and administration of excessive phytonadione may worsen hepatic function.


  1. Barkhan P, Shearer MJ "Metabolism of vitamin K1 (phylloquinone) in man." Proc R Soc Med 70 (1977): 93-6
  2. Shearer MJ, McBurney A, Barkhan P "Studies on the absorption and metabolism of phylloquinone (vitamin K1) in man." Vitam Horm 32 (1974): 513-42
  3. Ballard HS, Marcus AJ "Decompensated portal cirrhosis. Effects of large doses of phytonadione." Arch Intern Med 117 (1966): 182-6
  4. "Product Information. Vitamin K (phytonadione)." Apothecon Inc (2022):
  5. "Product Information. Mephyton (phytonadione)." Merck & Co., Inc (2001):
View all 5 references

Vitamin K2 drug interactions

There are 11 drug interactions with Vitamin K2 (menaquinone).

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.