Vitamin K deficiency

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Vitamin K deficiency
phytonadione

Vitamin K deficiency results from insufficient dietary vitamin K1 or vitamin K2 or both.[1]

Signs and symptoms

Symptoms include

petechiae,[2][3]
and haematoma.

Vitamin K is changed to its active form in the liver by the enzyme

VII, IX, X, and protein C and protein S. Inability to activate the clotting cascade via these factors leads to the bleeding symptoms mentioned above.[citation needed
]

Notably, when one examines the lab values in Vitamin K deficiency [see below] the

factor VII
has the shortest half-life of all the factors carboxylated by vitamin K; therefore, when deficient, it is the PT that rises first, since the activated Factor VII is the first to "disappear." In later stages of deficiency, the other factors (which have longer half lives) are able to "catch up," and the PTT becomes elevated as well.

Cause

Vitamin K1-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of a vitamin K1-antagonist such as warfarin, or, very rarely, by nutritional vitamin K1 deficiency. As a result, Gla-residues are inadequately formed and the Gla-proteins are insufficiently active.[citation needed]

Epidemiology

The

the classic hemorrhagic disease occurring in 0.25-1.7% of infants.[2] Therefore, the Committee on Nutrition of the American Academy of Pediatrics recommends that 0.5 to 1.0 mg Vitamin K1 be administered to all newborns shortly after birth.[4]

Postmenopausal and elderly women in Thailand have high risk of Vitamin K2 deficiency, compared with the normal value of young, reproductive females.[5] Current dosage recommendations for Vitamin K may be too low.[6] The deposition of calcium in soft tissues, including arterial walls, is quite common, especially in those who have atherosclerosis, suggesting that Vitamin K deficiency is more common than previously thought.[7]

Because

colonic bacteria synthesize a significant portion of the Vitamin K required for human needs, individuals with disruptions to or insufficient amounts of these bacteria can be at risk for Vitamin K deficiency. Newborns, as mentioned above, fit into this category, as their colons are frequently not adequately colonized in the first five to seven days of life. Another at-risk population comprises those individuals on any sort of long-term antibiotic therapy, as this can diminish the population of normal gut flora.[8]

See also

  • Haemorrhagic disease of the newborn

References

  1. ^ "Vitamin K Deficiency: Background, Physiology, Complications and Prognosis". 24 January 2022. {{cite journal}}: Cite journal requires |journal= (help)
  2. ^ a b c Vitamin K Deficiency eMedicine. Author: Pankaj Patel, MD. Coauthor(s): Mageda Mikhail, MD, Assistant Professor. Updated: Feb 13, 2014
  3. ^ "Causes". Mayo Clinic.
  4. PMID 12837888
    .
  5. PMID 17982197
    .
  6. PMID 16030366
    .
  7. PMID 15613016
    .
  8. PMID 6047959
    .

External links

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