Discovered in 1929, vitamin K is a group of 3 fat soluble vitamins: vitamin K1, vitamin K2, and vitamin K3. It is used to make prothrombin and other blood clotting proteins, it is necessary in converting osteoclacin to its active from, and is necessary for the production of a urinary protein involved in kidney function.
Blood clotting: Vitamin K is essential in blood clotting. Vitamin K assists in taking the protein prothrombin and converting it to thrombin which assists in the blood clotting process. Without vitamin K your body could develop symptoms like easy bruising, frequent nosebleeds or cuts that will not stop bleeding or clot.
Bone metabolism: A bone protein known as osteocalcin regulates the function of calcium in bone mineralization. Vitamin K is necessary in order to convert the protein osteocalcin to its active form, it also aids in the function of the protein MGP which is present within bones, teeth and cartilage.
Kidney function: Vitamin K is necessary for the production of a urinary protein within the kidneys. This protein inhibits the production of kidney stones, because vitamin K is typically found in green leafy vegetables it is assumed that vegetarians have low occurrences of kidney stones compared to non-vegetarians.
Vitamin K1 = Phytonadione (Phylloquinone), Vitamin K2 = Menatrenone
Not enough research has been done to determine the proper dietary allowances for Vitamin K, but the Adequate Intake (AI) values are:
- Up to 6 months: 2 micrograms (mcg)
- 6 to 12 moths: 2.5 mcg
Children and Adolescents
- 1 to 3 years old: 30 mcg
- 4 to 8 years old: 55 mcg
- 9 to 13 years old: 60 mcg
- 14 to 18 years old: 75 mcg
- Pregnant, lactating, and/or 14 to 18 years old: 75 mcg
- Pregnant, lactating, and/or 20 years old and older: 90 mcg
- 20 years old and older: 120 mcg
A deficiency in vitamin K is rare and generally occurs in those who have prolonged diarrhea, jaundice (obstructive), liver disease or malabsorption problems, like celiac disease. However, it can occur in newborns and the elderly. Some signs and symptoms of a vitamin K deficiency are prolonged clotting time, easy bleeding/bruising, frequent nose bleeding, blood-stained urine and bleeding from the gut.
Sources in the Diet
Vitamin K is typically found in dark, leafy green vegetables like broccoli, spinach, and cabbage. It can also be found in avocados, turnips, pistachio nuts, watercress, plums, canola oil and kiwis among others. However, freezing or purchasing these vegetables frozen may destroy the vitamin K so it is best to purchase these foods fresh rather than frozen.
Recent Studies and Articles
Vitamin K and aging
Vitamin D absorption and sunscreen
Vitamin K and osteoporosis
Physical Characteristics: Oil or spray dried powder, light yellow
Formulation Notes: K2 is ~six times the cost of K1, stability overcome with moderate overages. Where used is regulated.
K1 PHYTONADIONE 1% TRIT, 44 LB (20 KG.) CARTON
E ACETATE 50% C.W.D. , 22 LB (10 KG) IP BAG
A ACETATE 500/STARCH , 25 LB CARTON
K1 5% SPRAY DRIED , 28 GAL L.P. DRUM 100LBS
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-  – Dole Nutrition Institute. The Dole Nutrition Handbook. Printed in the United States of America; Rodale Inc. 2010.
-  – http://www.nlm.nih.gov/medlineplus/druginfo/natural/983.html