Vitamin K Deficiency

Etiology

Vitamin K Deficiency

Vitamin K Antagonism

  • Coumadin (Warfarin) (see Coumadin, Coumadin): inhibits the hepatic gamma carboxylation of glutamic acid
  • Coumadin-Containing Herbs
    • Chamomile (Matricaria Recutita, Chamaemelum Mobile) (see Chamomile, Chamomile)
    • Fenugreek (Trigonella Foenum-Graecum) (see Fenugreek, Fenugreek)
    • Horse Chestnut (Aesculus hippocastanum)
    • Motherworth (Leonurus Cardiaca)
    • Red Clover (Trifolium Pratense)
  • High-Dose Vitamin E (see Vitamin E, Vitamin E)

Clinical Manifestations

Hematologic Manifestations

  • Prolonged PT/INR (see Coagulopathy, Coagulopathy): vitamin K-dependent clotting factor activity is more reflected in the PT/INR than in the PTT
  • Factor II/VII/IX/X Levels: decreased
    • If factor V is also low, as well, this suggests a defect in hepatic synthetic function and cannot be attributed to vitamin K deficiency alone

Rheumatologic Manifestations

  • Increased Risk of Fractures/Osteoporosis (see Osteoporosis, Osteoporosis): due to role of vitamin K in the synthesis of bone proteins, such as osteocalcin

Other Manifestations

  • Hemorrhagic Disease of the Newborn
    • Early Onset: intracranial and retroperitoneal bleeding (occurring at 1-7 days postpartum)
    • Late Onset (occuring as late as 3 months postpartum)
    • To prevent this in newborns (who have minimal hepatic stores of vitamin K at birth), vitamin K is given prophylactically soon after birth

Treatment

  • Oral Vitamin Vitamin K1 (Phytonadione) (see Vitamin K, Vitamin K): 5-10 mg /day
    • Excellent absorption
    • Expected improvement in INR within 1 day
  • Subcutaneous Vitamin K
    • Absorption is erratic
  • Intravenous Vitamin K1 (Phytonadione) (see Vitamin K, Vitamin K): 1 mg/day

References

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