Vitamin K

Front 1

What does Vitamin K stand for?

Back 1

Koagulation (Danish spelling). Quinones.

Front 2

What is Vitamin K's main function?

Back 2

Blood clotting

Front 3

What are the best sources of Vitamin K?

Back 3

Best sources – Green leafy veg (kale, turnip greens, parsley, saladgreens, collards, cabbage, spinach), broccoli, peas, greenbeans

Front 4

What percentage of Vitamin K is obtained from dietary sources?

Back 4

90%

Front 5

What are the 2nd major sources of Vitamin K?

Back 5

Veg oils (soy, canola), margarine

Front 6

What sources contain small amounts of Vitamin K?

Back 6

Cereals, fruit, dairy products, meats

Front 7

Where is the remaining 10% of Vitamin K produced?

Back 7

Bacterial synthesis in colon. Not sufficient enough to meet needs of healthy adults/kids

Front 8

Where can Phylloquinones be mostly obtained?

Back 8

Vit K1- from plants. Naturally occurring from green plants. Main dietary form and most biologically active.

Front 9

Where can Menaquinones be mostly obtained?

Back 9

Vit K2- from fish oils, meats, and bacteria. Synthesized by bacteria in Colon.

Front 10

Where can Menadione be mostly obtained?

Back 10

Synthetic vit K - Can be converted to menaquinone in body

Front 11

What % of phylloquinone is absorbed and where?

Back 11

~80% as phylloquinone is abs into small int and incorporated into chylomicron

Front 12

Where is Menaquinone absorbed?

Back 12

Menaquinone – From bacterial synthesis is abs from ileum and colon into bloodby passive diffusion

Front 13

How is Phylloquinone primarily excreted?

Back 13

Primarily exc via bile in feces.

Small amount in urine.

Front 14

What are the functions of Vitamin K?

Back 14

Blood Clotting (Functions as a coenzyme during the synthesis of the biologically active form of a number of proteins involved in blood coagulation)

Bone Metabolism (3 vitamin K-dependent Gla proteins (Osteocalcin,Matrix Gla Protein (MGP),Protein S) synthesized in bones Functions are not clearly understood. However, synthesis of these proteins is decreased in vit K def animals and results in changes in bone health)

Front 15

What are the different types of interactions with Vitamin K?

Back 15

Coumadin (Warfarin)

Vitamins A & E

Vitamin D

Front 16

Coumadin (Warfarin) - Vitamin K interaction

Back 16

Coumadin (Warfarin) Anticoagulation medication – Prescribed for those at risk for thrombic event Antagonizes the synthesis of vit K Inhibits reactivation process->decreases synthesis of vit K-dependent clotting factors Dietary Restriction – Need to maintain consistent vit K intake and avoid vit K supplementation Increased intake can lead to warfarin resistance

Front 17

Vitamins A & E- Vitamin K interaction

Back 17

Increased intake of vit A & E – Can antagonize actions of vit K alpha-tocopherol – Can inhibit carboxylase Excessive vit A intake can interfere with vit K abs Vit E – Possible inhibition of vit K abs, function and metabolism However, high intake of vit E has not been reported to antagonize vit k status in healthy adults Megadoses of vit A and E – Can increase risk of vit K def and bleeding

Front 18

Vitamin D - Vitamin K interaction

Back 18

Involved in relationship to calciumVit D’s functions affect calcium metabolismVit K-dependent proteins bind calcium for function

Front 19

Deficiency of Vitamin K

Back 19

Newborns – Low stores of vit K as inadequate amounts cross placenta Also do not have bacterial population for synthesis Are at increased risk for bleeding b/c defective blood clotting In N America – Given vit K injections w/in 6 hours of delivery

Deficiency is rare At Risk – Prolonged antibiotic use Impaired fat abs Severe def – Associated with hemorrhage

Front 20

Toxicity of Vitamin K

Back 20

No UL – Storage is limited and more readily exc than other fat-sol vit

Natural forms – No harmful effects or s/s toxicity

Synthetic form – Can cause liver damage, hemolytic anemia, jaundice (excess bilirubin in blood) and death in newborns

No longer give injections for treatment of def

Front 21

How is Vitamin K assessed?

Back 21

Plasma Phylloquinone concentration

PTT – Prothrombin Time Measures

Front 22

Plasma Phylloquinone concentration

Back 22

Reflects recent intake Shown to respond to changes in dietary intake. However, varied amounts in food, therefore single level may not reflect normal dietary intake.

Front 23

PTT – Prothrombin Time

Back 23

Measures time required for a fibrin clot to form.Measures clotting time for potential def.