Vitamin K Deficiency

Vitamin K Deficiency Testing and health information

Excessive or unexpected bleeding usually leads to the discovery of vitamin K deficiency. The main lab tests to examine the bleeding are the prothrombin time (PT/INR) and the Vitamin K blood test for blood levels.


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Diagnosing Vitamin K Deficiency; the body requires small regular amounts of Vitamin K. This nutrient is important in the formation of coagulation factors, protein S, and protein C. When blood vessels are injured, all these substances help in the blood’s clotting. They also ensure excessive clotting is prevented. Easy bruising and extreme bleeding can be caused by inadequate vitamin K. Also, this nutrient has an important role when it comes to bone loss prevention. Low bone density has been associated with low levels of vitamin K within the blood. There is some evidence suggesting that enough vitamin K levels lead to bone health improvement. Such levels also reduce fracture risks.

Vitamin K exists in three different types:

  • Vitamin K1 comes from foods. It also goes by the name phylloquinone or phytomenadione. Green leafy vegetables, vegetable oils, and dairy products are the source of vitamin K1. It is regarded as vitamin K’s “plant form.” The commercial production of K1 is also done for the treatment of conditions linked to excess bleeding.  
  • Bacteria are used in the production of vitamin K2 (menaquinones). It is produced by the intestines’ normal flora. The conversion of K1 into K2 is made possible by intestinal bacteria. The body’s requirements are met when the diet is supplemented by vitamin K2.    
  • K3 (menadione) is a synthetic chemical compound that is non-natural. This nutritional supplement is used in some countries due to its vitamin K activity. Menadione supplements aren’t allowed for human use in the US due to their potential toxicity. The body must take in a certain amount of vitamin K through the diet since enough amounts of this nutrient aren’t produced by the body. This vitamin is present within many food varieties. It is normally supplied in enough levels in the regular diet in the USA.

Various foods contain high levels of vitamin K per serving. They usually exceed the Recommended Daily Allowance (RDA). These foods consist of leafy green vegetables, including spinach, kale, green leaf lettuce, and collards. Other vegetables such as asparagus, broccoli, cabbage, and brussels sprouts also fall under this category. Dairy products, soybeans, cereals, and vegetable oils also add up as other sources. Both K1 and K2 are fat-soluble. They are stored in the fat tissue and liver of the body. Vitamin K that’s worth a week is typically stored by an adult.

Factors That Result in Vitamin K Deficiency          

Insufficient dietary intake, decreased vitamin K storage because of liver disease, and inadequate absorption are the common causes that result in vitamin K deficiency. A decrease in its production within the intestines may also lead to its deficiency.

Healthy individuals in the US rarely experience dietary deficiency of vitamin K. This is, however, relatively common with individuals that have certain chronic conditions or are severely ill. For instance, it is commonly witnessed in patients suffering from serious illnesses such as cancer patients who are undergoing chemotherapy and chronic dialysis patients. It can also be seen in individuals at risk for malnutrition, such as those that have poor dietary habits that are linked to drug abuse or alcoholism.

Malabsorption can result in vitamin K deficiency. This can more so be caused by impaired fat absorption due to conditions such as celiac disease, Crohn’s disease or chronic pancreatitis, and cystic fibrosis. Malabsorption can also be caused by cholestatic liver diseases such as primary biliary cirrhosis or bile duct obstruction. This results in vitamin K deficiency. The absorption of vitamin K can be affected by medications such as antacids, antibiotics, as well as anti-seizure drugs. These medications can also affect the amount of K2 produced within the intestines or even lead to vitamin K’s degradation. Vitamin K requirements may be increased through the consumption of high aspirin doses.

Insufficient normal flora within the intestines of newborns can result in vitamin K deficiency. Vitamin K may also not be present in enough levels from breast milk. Also, vitamin K deficiency may occur once the infant is born if the infant’s mother was on certain medications such as anti-seizure medications while pregnant. These incidents are usually linked to vitamin K deficiency bleeding or VKDB. It is also referred to as hemorrhagic disease of the newborn. It can result in extreme bleeding and bruising. Severe cases may result in fatal brain bleeding.

VKDB was a relatively common occurrence in the past. Luckily, it has subsided since the introduction of the vitamin K injection that’s administered shortly after newborns are delivered. The American Academy of Pediatrics recommends its administration. Vitamin K may also be administered to help with excessive infant bleeding in instances where surgeries are required.   

A frequent question asked is if individuals that have used the anticoagulant drug warfarin in their treatment shouldn’t eat foods rich in vitamin K. It is also common for people to query whether the risk of vitamin K deficiency is heightened by limiting such foods after being treated with Coumadin®.

Individuals with various conditions, including cardiovascular diseases (CVD) and deep vein thrombosis (DVT), are prescribed with warfarin. It helps “thin” their blood. Inappropriate clotting is prevented using this drug. A test termed as PT/INR is usually done to determine how effective the dose “thins” the blood after the prescription of warfarin by a healthcare practitioner. The adjustment of this dose is determined by the test results. This adjustment ensures excessive bleeding is prevented through the prescription of the right amount of the dose.

The ability of the liver to use vitamin K in the production of blood-clotting factors is reduced by taking warfarin. This implies that an antagonism exists between warfarin and vitamin K. They counteract each other. The success of warfarin in the prevention of blood clots without resulting in excess bleeding is dependent on the significant decreases or increases in the vitamin K amounts consumed by an individual. Individuals who are under warfarin prescriptions need to take in a consistent amount of foods rich in vitamin K every day rather than avoid them. Through consistency in the food amount that’s consumed, these individuals can get their much-needed vitamin K.    

Signs and Symptoms

Vitamin K deficiency can be associated with the following signs and symptoms:

  • An increase in prothrombin time (PT/INR)
  • Intense menstrual periods
  • Urine and/or stool that contains blood
  • Easy bruising
  • Oozing from either gums or nose
  • Extreme bleeding from punctures, wounds, and surgical or injection sites
  • Bleeding from the GI (gastrointestinal) tract

The signs and symptoms mentioned above may be similar in vitamin K deficiency bleeding involving newborns. More serious cases in newborns involve intracranial hemorrhage. 

Questions may be raised on whether one is vitamin K deficient if the symptoms mentioned above are observed in an individual with an increased risk, say:

  • Individuals with chronic conditions linked to malabsorption or malnutrition
  • Individuals who’ve been undergoing treatment for a long-time using antibiotics; the medications act by killing the bacteria responsible for vitamin K2 production in the small intestine.
  • Severely sick patients such as dialysis or cancer patients


Excessive or unexpected bleeding usually leads to the discovery of vitamin K deficiency. The principal laboratory test that’s conducted to examine the bleeding in such cases is the prothrombin time (PT/INR). The administration of vitamin K by injection is done if it is suspected that the bleeding may have been as a result of low vitamin K levels. An assumption is made that a vitamin K deficiency caused the bleeding if it stops, and the PT is normalized.

Occasionally, other coagulation tests may be performed to an individual with excessive bleeding and bruising symptoms. They include thrombin time, partial thromboplastin time (PTT), platelet function tests, platelet countfibrinogend-dimer, coagulation factor tests, and von Willebrand factor.