|
Hemorrhagic Disease Of The Newborn
Vitamin K deficiency bleeding (VKDB) of the newborn, previously known as haemorrhagic disease of the newborn, is a rare form of bleeding disorder that affects newborns and young infants due to low stores of vitamin K at birth. It commonly presents with intracranial haemorrhage with the risk of brain damage or death. Newborn infants have low stores of vitamin K, and human breast milk has low concentrations of the vitamin. This combination can lead to vitamin K deficiency and later onset bleeding. Vitamin K deficiency leads to the risk of blood coagulation problems due to impaired production of clotting factors II, VII, IX, X, protein C and protein S by the liver. More rarely VKDB can be caused by maternal medicines causing vitamin K deficiency in the newborn. VKDB can largely be prevented by prophylactic supplementation of vitamin K, which is typically given shortly after birth by intramuscular injection. Most national health organisations recommend routine vitamin K supplementati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation (K from ''Koagulation'', German for "coagulation") or for controlling binding of calcium in bones and other tissues. The complete synthesis involves final modification of these so-called "Gla proteins" by the enzyme gamma-glutamyl carboxylase that uses vitamin K as a cofactor. Vitamin K is used in the liver as the intermediate VKH2 to deprotonate a glutamate residue and then is reprocessed into vitamin K through a vitamin K oxide intermediate. The presence of uncarboxylated proteins indicates a vitamin K deficiency. Carboxylation allows them to bind (chelate) calcium ions, which they cannot do otherwise. Without vitamin K, blood coagulation is seriously impaired, and uncontrolled bleeding occurs. Research suggests that deficiency of v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
