Vitamin K deficiency is mainly due to
- Chronic gastrointestinal diseases, for example, deficient absorption in Crohn’s disease, decreased utilization in liver cirrhosis and cholestasis, transport disturbances due to, for example, lymphatic drainage disorders or insufficient carrier protein (VLDL).
- Interactions with drugs especially is blocked by prolonged use of antibiotics (for example, ampicillin, cephalosporins or tetracyclines) or by overdose of anticoagulants (coumarin derivatives such as Marcumar) the vitamin K cycle via enzyme inhibition
- Inadequate intake, especially in patients with eating disorders, such as bulimia nervosa, or parenteral nutrition without adequate substitution.
A deficit of vitamin K leads to blood clotting disorders, because in the case of an undersupply, the vitamin K-dependent clotting proteins can no longer be converted into their active form in the liver. Accordingly, ineffective acarboxy precursors of coagulation factors (PIVKA) indicate vitamin K deficiency. Factor 2 of blood clotting, prothrombin, is of essential importance. This plasma protein is formed in the liver with the assistance of vitamin K and converted into thrombin with the help of prothrombinase. In the case of vitamin K deficiency, the reduced synthesis results in lowered prothrombin levels, which lead to a prolongation of the blood clotting time thromboplastin time, quick value. The increase in thromboplastin time due to low clotting activities in peripheral blood may result in hemorrhages (bleeding) of the following magnitude.
- Hemorrhages in tissues and organs (visible hemorrhages in gastrointestinal and genitourinary tracts, lungs, skin, and mucosa; nonvisible hemorrhages in brain, liver, adrenal gland, and retina).
- Bleeding from body orifices
- Hematemesis (vomiting blood)
- Hepatogenic (originating from the liver) hemorrhagic diathesis increased bleeding tendency with too long, too strong or too quickly triggered bleeding.
- Spontaneous bleeding, inadequate bleeding in injuries (coagulopathy increased bleeding tendency due to disruption of plasma factors with the formation of hematomas (bleeding in tissues under the skin and in muscles) and in severe forms of hemarthrosis (bruising in a joint)
- Inadequate bleeding after surgery
Newborns and breastfed infants are at particularly high risk of developing vitamin K deficiency. Causes of vitamin K deficiency in newborns and breastfed infants.
- Low vitamin K transfer through the placenta.
- Bacterial vitamin K synthesis in the intestine is still insufficient initially
- The immature liver is not yet able to synthesize sufficient amounts of clotting factors
- It takes weeks for the activities of vitamin A-dependent coagulation proteins to equal adult levels
- Low vitamin K content in breast milk, especially if breastfed infants drink too little in the first few days (about 0.5 µg/100 ml)
- Newborns fed with industrially produced infant formula (vitamin K content according to the Dietary Regulation at least 4 µg/100 ml) are at risk of developing vitamin K deficiency if feeding does not start on the first day of life [5, 6, 10, 12 ]
Signs of vitamin K deficiency in newborns and breastfed infants.
- Decreased prothrombin levels, which drop to 20-40% of the adult norm by the third day after birth
- Prolonged prothrombin time 19-22 seconds, normal 13 seconds.
Already in the first days of life, neonatal hemorrhagic disease can develop. For its development, in addition to vitamin K deficiency, the still immature protein synthesis of the infant plays a significant role. Hemorrhagic neonatorum disease is characterized by a dramatic decrease in coagulation factors 2, 7, 9, and 10, leading to severe bleeding.
- Between the 2nd and 7th day of life (classic form), gastrointestinal bleeding and leakage of blood from body orifices and umbilicus occur.
- Late bleeding usually after 3 weeks of life or after 1-3 months is more problematic, especially when there is severe bleeding after injury, mucosal bleeding, bloody stools (melena), and severe organ and cerebral hemorrhage.
- Intracranial hemorrhage can lead to neurologic and sensory damage
Newborns whose mothers took drugs for epilepsy or drugs for blood thinning within pregnancy are at particularly high risk for developing hemorrhagic neonatal disease. If coumarin derivatives are taken by the mother in early pregnancy, newborns are also at risk of developing severe bleeding, especially cerebral hemorrhage. In addition, the supply of these anticoagulants may cause skeletal deformities and hearing impairment in the infant, as well as disturbances in the formation of bone tissue due to inhibition of osteocalcin formation (fetal warfarin syndrome).
