Dr. Magryta: Vitamin K
K: Vitamin K is number four of four fat soluble vitamins. It has two forms, K1 phylloquinone and K2 menaquinone. The K stands for koagulation, german for coagulation.
The main function of vitamin K is as a cofactor for proteins involved in blood clotting and bone mineralization. These proteins are known as vitamin k dependent proteins, VKDP.
Our bones need calcium, osteocalcin and vitamin K to lay down mineralization crystals. Osteocalcin needs vitamin D for synthesis by bone cells.
K1 is made by plants and can be obtained by consuming the plant. K2 on the other hand is made in our intestines by bacteria that reside within us (healthy micro biome). K2 can also be found in fermented foods and animal meats.
Vitamin K is the only fat soluble vitamin that humans do not store well. We must consume it or make it to stay sufficient. We have a recycling mechanism in place called the vitamin k oxidation reduction cycle that allows us to reuse vitamin K many times. Why we don’t have this for other vitamins is a mystery.
Vitamin K sufficiency is especially critical in newborns. If a newborn has insufficient amounts of vitamin K in their body, they can suffer from a bleeding disorder called hemorrhagic disease of the newborn or vitamin K deficiency bleeding of the newborn. This deadly disease is easily prevented by a vitamin K injection after a child is born.
Vitamin K defiency is rare and usually due to liver disease and severe malnutrition. Inflammatory bowel disorders, intestinal dysbiosis, fat malabsorption disorders, eating disorders, celiac disease and disorders of bile production or pancreatic enzyme production and older age increase the risk of deficiency and insufficiency.
Symptoms are easy bruising and bleeding.
Chronic vitamin K insufficiency may be associated with diseases like osteoporosis, artery calcifications and heart disease.
Food sources of Vitamin K are leafy greens, animal livers and fortified foods like cereals.
Most adults need 75-90 micrograms/day. Incrementally less for kids. This nutrient is easily obtained by a healthy anti inflammatory diet.
Pregnancy and infancy are times of increased vitamin K needs. We highly stress the need for adequate vitamin K stores for all females of child bearing age.
There is no toxic level for vitamins K1 or K2.Vitmain K3, a synthetic version, has been associated with toxicity and should be avoided.
Vitamin A and E can interact with vitamin K dependent enzymes increasing the risk of bleeding in patients taking blood thinners like warfarin.
Anti-clotting or anti-coagulant drugs will interfere with vitamin K function and thus are a risk for chronic artery calcifications and acute bleeding.
Dr. Chris Magryta is a physician at Salisbury Pediatric Associates. Contact him at email@example.com