The prothrombin of the blood is elaborated in the liver. Andrus et al. (1939), and Warren and Rhoads (1939) produced experimental evidence in support, of this hypothesis. By total and partial hepatectomy in animals they produced a profound reduction in plasma prothrombin concentration which was unaffected by treatment with vitamin K and bile salts. It has been found essential to have vitamin K ...

Coronary artery calcification is a recognised risk factor for ischaemic heart disease and mortality. Evidence is now strong that Mönckeberg's arteriosclerosis, a form of vascular calcification, can be attributable to vitamin K deficiency, but that vitamin K-2, especially the MK-4 form from foods like cheese can be protective. Warfarin blocks the recycling of hepatic and peripheral vitamin K lea...

Anecdotal observations of the behavior of rats with a vitamin K-deficiency suggested that this deficiency was associated with hypoactivity, general malaise, and a lack of exploratory behavior. These observations were pursued by assessing locomotor activity in a circular photocell-monitored track, open-field activity, and radial-arm maze performance in rats rendered vitamin K-deficient by dietar...

To report a case of a 4 months old girl presenting with massive spontaneous proptosis, due to a large hematoma resulting from systemic vitamin K deficiency. Systemic features resolved with appropriate medical management, but proptosis was persistent and needed surgical intervention to prevent visual loss. Such a presentation of vitamin K deficiency has not been previously reported in the litera...

A 21-year-old primigravida had a pregnancy complicated by hyperemesis gravidarum (HG) beginning at 7-week gestation. Despite medical therapy, she lost 18% of her prepregnancy weight. Early ultrasound at 14 weeks demonstrated a flattened facial profile with nasal hypoplasia (Binder phenotype) consistent with vitamin K deficiency from HG. She had a percutaneous endoscopic gastrojejunostomy tube p...

The incidence of Alzheimer's disease (AD) increases with age and in carriers of the apolipoprotein E4 genotype. A relative deficiency of vitamin K, affecting the extrahepatic functions of the vitamin, is common in ageing men and women. The concentration of vitamin K is lower in the circulating blood of APOE4 carriers than in that of persons with other APOE genotypes. Evidence is accumulating th...

A 61-year old woman with atrial fibrillation developed macrohaematuria during anticoagulant treatment with a direct oral factor Xa inhibitor for stroke prevention. Abnormal results of coagulation assays were first interpreted as an effect of the anticoagulant. However, upon further testing diagnosis of vitamin K deficiency was established. After vitamin K supplementation, coagulation tests norm...

Experimental work during the years 1929 to 1934 established the fact that a haemorrhagic disease observed in chicks was due to deficiency of a fatsoluble dietary factor: in 1935 Dam proposed the nane vitamin K (Koagulations vitamin) for this factor. Dam, Sch0nheyder and Tage-Hansen in 1936 demonstrated a hypoprothrombinaemia which prolonged the clotting time in vitamin-K-deficient chicks, altho...

Hemorrhagic disease of the newborn or, more precisely, vitamin K deficiency bleeding (VKDB) in infancy, according to the Committee of the International Society on Thrombosis and Hemostasis (1), is a bleeding disorder due to vitamin K deficiency. It generally occurs during the neonatal period, but it is occasionally seen in infants several months old (2–4). The postnatal administration of vitami...