What Causes Vitamin K Deficiency?

Symptoms of Vitamin K Deficiency

Vitamin K deficiency is rare among healthy adults because the body usually maintains sufficient levels through a cycle called the Vitamin K oxidation-reduction cycle, and thanks to the presence of vitamin K-producing beneficial bacteria in the large intestine. Moreover, vitamin K is abundant in many foods. However, when levels drop, the most noticeable effect is an increased risk of excessive bleeding due to impaired blood clotting.

Vitamin K1 and K2 are responsible for producing proteins that promote blood coagulation, reducing the risk of both internal and external bleeding. A deficiency means these proteins are not produced in adequate amounts, leading to more severe bleeding when injuries occur.

Increased bleeding is not always linked to visible wounds and can present as:

• Easy bruising or contusions
• Small blood clots under the nails
• Nosebleeds or bleeding from mucous membranes
• Dark stools containing blood
• Blood in urine
• Heavier menstrual bleeding in women
• Gastrointestinal bleeding
• Prolonged prothrombin time (the time it takes for blood to clot)

Vitamin K Deficiency in Newborns

In newborns, deficiency can be detected by symptoms such as bleeding at the site of the umbilical cord removal, skin or nose bleeding, bleeding from the penis after circumcision, and in severe cases, sudden brain hemorrhage, which poses a life-threatening risk.

Complications of Vitamin K Deficiency

The effects of vitamin K deficiency vary with age. In newborns, it may cause Hemorrhagic Disease of the Newborn, leading to intracranial bleeding or bleeding in the retroperitoneal space within the abdomen. This typically occurs within the first week after birth but can also appear up to three months later.

Additionally, vitamin K plays a role in bone health by supporting the production of osteocalcin, a hormone essential for bone formation, linking deficiency to osteoporosis risk.

Risk Factors for Vitamin K Deficiency

In Adults

Vitamin K deficiency can arise from insufficient dietary intake or conditions that impair absorption. Key risk factors include:

• Diseases causing fat malabsorption, such as celiac disease, cystic fibrosis, and bile duct disorders
• Partial removal of the intestine
• Diabetes
• Chronic kidney diseases
• Liver diseases
• Use of certain medications and supplements, including:
  • Anticoagulants that inhibit vitamin K activity
  • Antibiotics that interfere with vitamin K production and absorption
  • High doses of vitamins A and E

In Children

Factors increasing vitamin K deficiency risk in infants include:

• Low vitamin K stores at birth, since the placenta transfers minimal amounts to the fetus
• Delayed development of beneficial gut bacteria that produce vitamin K
• Exclusive breastfeeding, as breast milk contains lower vitamin K levels compared to formula
• Liver disease impairing vitamin K utilization
• Conditions such as diarrhea, celiac disease, and cystic fibrosis
• Mothers taking certain medications during pregnancy or breastfeeding, like anticonvulsants, anticoagulants, or tuberculosis drugs

Diagnosis of Vitamin K Deficiency

To determine if bleeding is due to vitamin K deficiency or other causes like liver disease, tests measuring vitamin K levels and Factor V (a liver-produced clotting protein) are used. In liver disease, both vitamin K and Factor V levels decrease, whereas in isolated vitamin K deficiency, Factor V remains normal. Blood clotting speed tests are also part of the diagnosis.

Treatment of Vitamin K Deficiency

Vitamin K deficiency is commonly treated with supplements containing vitamin K1, available as oral tablets or subcutaneous injections. Adults typically receive doses between 1-25 mg, while patients on anticoagulants need smaller doses (1-10 mg) due to drug interactions.

Newborns are recommended a 0.5-1 mg dose of vitamin K1 at birth, with higher doses if the mother uses certain medications. Treatment plans for children depend on age, health status, symptom severity, and may include blood transfusions in cases of severe bleeding.

For dietary sources of vitamin K, refer to specialized articles discussing rich food sources.

Recommended Daily Intake of Vitamin K

Overview of Vitamin K

Vitamin K is a fat-soluble vitamin that exists mainly in two forms: vitamin K1 (phylloquinone), abundant in leafy green vegetables like kale and spinach, and vitamin K2 (menaquinones), found in smaller amounts in animal products such as meat, cheese, eggs, fermented foods, and also produced by gut bacteria.

This vitamin is essential for blood clotting and plays a significant role in preventing excessive bleeding. It may also contribute to maintaining bone strength with age. Vitamin K1 is the primary form used in supplements, though it is less commonly administered compared to other forms.

For more detailed information about vitamin K benefits, consult articles specifically dedicated to this vitamin.