Vitamin K1

Serum, 1ml

Explicitly light-protected material is not necessary for this analysis. Until shipment, the samples must be protected from direct sunlight (storage on window sills should be avoided). The samples can be stored in the shipping bags (M112) without light protection until shipment.

The most important naturally occurring fat-soluble vitamin K compounds are vitamin K1 (phylloquinone) and vitamin K2 (menaquinone). Menaquinone is considered to be the more effective K vitamin in humans. It can be partly replaced by phylloquinone, which is supplied by vegetable food when the intestinal flora is intact. The half-life in the blood is about 1 to 4 hours for vitamin K1, but 48 to 72 hours for the more lipophilic vitamin K2 subtype menaquinone-7.
The physiological effects of vitamin K1 include: intrahepatic formation of the prothrombin complex (factors II, VII, IX, X), activation of protein C and protein S; extrahepatic formation of osteocalcin in the osteoblasts.
According to the Deutsche Gesellschaft für Ernährung (German Nutrition Society), the daily vitamin K requirement is approx. 1 μg/kg body weight. Vitamin K1 is found in virtually all green vegetables and is particularly abundant in kale, spinach, lettuce, fennel, Brussels sprouts and chickpeas.

Reduced: Malabsorption, bile duct obstruction, parenteral nutrition, bile fistulas, vitamin K antagonists. Symptoms of deficiency: Hemorrhages. In newborns whose mothers were not sufficiently supplied with vitamin K, intracranial bleeding due to hypoprothrombinaemia may occur.
Increased: No alimentary or therapeutic overdosing is known, but the effect of oral anticoagulants of the coumarin type may be attenuated. This should be considered in particular when supplementing menaquinone-7.
Note: the quick value is better suited for (indirect) assessment of the vitamin K level. See also vitamin K2.