Vitamin K Deficiency

Vitamin K is a group of fat-soluble compounds that the body requires for bone development, blood coagulation, and cardiovascular health. A deficiency of vitamin K can result in poor bone development, bleeding, increased cardiovascular disorders, and osteoporosis.

The National Academy of Science Food and Nutrition Board recommends that the adequate intake of Vitamin K for men and women is 120 ug/day and 90 ug/day, respectively.

Vitamin K occurs in two forms. The first is Vitamin K-1, also known as phylloquinone, which can be found in green leafy vegetables due to its direct involvement in photosynthesis. Examples of sources of vitamin K-1 include kale and spinach.

The second is vitamin K-2, also known as menaquinone, which is created naturally in the intestinal flora. It is formed when bacteria in the gut convert vitamin k-1.

Vitamin k-1 and vitamin k-2 produce proteins that are involved in the coagulation of blood (blood clot). This prevents excessive bleeding, both internally and externally.

Although Vitamin K deficiency can occur in any age group, it is rare in adults and commonly occurs in infants who are born with low levels of vitamin K. Adults obtain an adequate supply of the vitamin from their diet and the body’s natural process.

However, certain medical disorders and medications increase and adult’s risk of being vitamin K deficient. These conditions and diseases may interfere with the body’s absorption of the vitamin.

Causes and Risk Factors of Vitamin K Deficiency

Medical Condition

Certain medical conditions may put on an adult at risk of being deficient in vitamin K. These conditions may interfere with the body’s ability to absorb fats.

This consequently inhibits the absorption of vitamin K. Diseases that can impair the absorption of fat in an adult include:

  • Celiac disease
  • Cystic fibrosis
  • Crohn’s disease
  • Chronic pancreatic
  • Cholestatic liver diseases
  • The removal of some parts of the intestine


Older people are at an increased risk of vitamin K deficiency when they take certain medications. The medicines associated with the symptoms of vitamin K deficiency include:

  • Antibiotics that destroy the gut flora and consequently interferes with the production and absorption of vitamin K
  • Anticoagulants that inhibit vitamin K and prevent the coagulation of blood.
  • Antacids
  • Anti-seizure medication
  • Extremely high dosage of vitamin E
  • Excess intake of vitamin A


Infants are more likely to be deficient in vitamin K than adults. This occurs as a result of:

  • Insufficient amounts of vitamin K in breast milk
  • Vitamin K does not transfer properly from the placenta of the mother to the child
  • An infant’s liver is unable to utilize vitamin K efficiently
  • A newborn baby’s gut cannot produce vitamin K-2 (menaquinone) in the first few days of life

Signs and Symptoms of Vitamin K Deficiency

There are a variety of signs associated with the deficiency of vitamin K; however, the primary symptom is excessive bleeding. This symptom may not be immediately apparent, it only occurs when the person is wound or cut.

Other symptoms of vitamin K deficiency include

  • The appearance of small clots under the nails
  • Bruising easily
  • Dark-colored or bloody stools
  • Bleeding in the mucous membranes that line the areas inside the body

In newborn babies and infants, the symptoms are:

  • Bleeding at the penis long after circumcision
  • Excessive bleeding from the area where the umbilical cord has been removed
  • Bleeding in the nose, skin, intestinal tract, among other areas
  • Sudden bleeding in the brain which can be severe and potentially life-threatening


Vitamin K deficiency is diagnosed by a medical professional reviewing the patient’s medical history. Vitamin K deficiency is suspected when an abnormal and prolonged bleed occurs, which puts the patient at risk.

Studies conducted on the blood coagulation capacity on the patient confirms the diagnosis of vitamin K deficiency. This coagulation test is also known as Prothrombin or PT test.

If the PT test time takes longer than 13.5 seconds to clot, the vitamin K deficiency may be suspected. All other factors such as platelet time, levels of fibrinogen, and fibrin-split products remain unchanged

If vitamin K-1 significantly decreases in the Prothrombin Test within 2 to 6 hours, a liver disease is not the likely cause, and the diagnosis of vitamin K deficiency is confirmed.

Some medical centers can detect vitamin K deficiency more efficiently by measuring the serum vitamin level. The serum level of vitamin K-1 ranges from 0.2 to 1.0 ng/mL in healthy people who consume sufficient quantities of vitamin K1 (50 to 150 mcg a day).

The knowledge of vitamin K intake can help interpret serum levels. Recent consumption affects levels in serum but not in tissues.

More sensitive indicators of vitamin K levels in the blood like undercarboxylated osteocalcin, and PIVKA (protein induced in vitamin K absence or antagonism) are currently under study.


The short-term treatment for vitamin K deficiency typically involves the administration of either oral supplements or injections.

A lifetime supply may be necessary for those who have underlying chronic conditions like celiac disease or Crohn’s disease. The action of vitamin K usually requires 2 to 5 days after it is administered to show treatment effects.

Issues with high levels of natural forms of vitamin K (both K-1 and K-2) have not been reported. These forms have low toxic effects, even at high concentrations.

However, water-soluble vitamin K-3 (menadione) can be toxic if given in large quantities. Also, K-3 is known to cause hemolytic anemia in infants, so it is not used in the treatment of little children.

The liver is responsible for the production of vitamin K blood clot factors. If a person has a chronic liver disorder, that person may not be able to produce adequate clotting factors even with the availability of vitamin K. Vitamin K supplementation may not be effective in those with severely damaged livers.

Prevention of Vitamin K Deficiency

0.5 to 1 mg IM of Vitamin K-1 is recommended for all newborns within 6 hours after delivery to reduce the incidence of brain hemorrhage due to trauma caused by delivery. It is also used as a prophylactic before surgery.

It is recommended that pregnant women taking anti-seizure medication receive a 10 mg dosage of vitamin K-1 orally once a day one month prior to delivery. Low vitamin K-1 in breast milk can be increased by increasing the dietary intake of vitamin K-1 to 5 mg/day.