Vitamin K update (2) on Deficiency, Drug Interactions, Laboratory Assessments
This is Part 2 following the Part 1 Introduction published earlier today.
This is Part 2 following the Part 1 Introduction published earlier today.
Deficiency
Acute deficiency of vK leads to bleeding disorders due to failure of hepatic production of clotting factors 2,7,9,10; long-latency deficiency of vK likely contributes to chronic disorders of osteoporosis, atherosclerosis, cancer, pain, inflammation and neuroinflammation/neurodegeneration. Newborn babies are at risk for vK/nutrient deficiency especially if the mother is nutrient deficient; adult risk factors for vK deficiency include malnutrition, malabsorption (eg, celiac, Crohn), hospitalization, antibacterial drugs (especially clindamycin and gentamicin), antiseizure drugs, anticancer drugs, consumption of fat/bile-sequestering drugs and hydrogenated/trans fats.
If the patient is taking warfarin or other vitamin K antagonist, and vitamin K intake is to be increased, then laboratory monitoring with INR and PT (discussed in the following section) must be performed and should be coordinated with/by the prescribing doctor. Dietary change or supplementation that increases vk intake will reduce the effect of warfarin, thereby increasing the risk of thrombosis, stroke, embolism, etc; this could result in devastating medical and legal/financial consequences.
Interactions
The most notorious and noteworthy drug interaction with vK is with the drug warfarin (brand names Coumadin and Jantoven) which is used as an anticoagulant/antithrombotic agent; warfarin competes with vK to inhibit gamma-carboxylation of clotting proteins 2,7,9,10 and therefore the dose of warfarin has to be proportional to the intake of vK.
Dietary change or supplementation that increases vk intake will reduce the effect of warfarin, thereby increasing the risk of thrombosis, stroke, embolism, etc; this could result in devastating medical and legal/financial consequences. If the patient is taking warfarin or other vitamin K antagonist, and vitamin K intake is to be increased, then laboratory monitoring with INR and PT (discussed in the following section) must be performed and should be coordinated with/by the prescribing doctor.
Laboratory Assessments of Vitamin K Deficiency
Laboratory assessment of vitamin K deficiency is not required prior to vitamin K supplementation.