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Vitamin K : Uses, Needs, Deficiency, Food Sources , Toxicity and Functions

Last updated on 2023-09-11T19:57:40 by Olayemi Michael Bsc (nutrition and dietetics) RDN


vitamin k: need and functions
“My nutritionist said I should add leafy green vegetables to my diet because of Vitamin K, I was told I need it because it helps in blood clotting” by an anonymous.
Vitamin K is one of the four members of fat-soluble Vitamin, It is a micro-nutrient of great importance with the fact that it is very important in blood clotting and its deficiency can lead to hemorrhaging.
Some years back, a Danish researcher first noted the relationship between vitamin K and blood clotting when he observed that chicks fed a diet with the fat extracted developed hemorrhages.
Thus, he named this new lipid-soluble factor “vitamin K” after coagulation, the Danish spelling for coagulation. Like Vitamin D, apart from a food source, vitamin K can be obtained from a non-food source. Bacteria in the GI tract synthesize vitamin K that the body can absorb.
read more : principles of nutritional laboratory testing
From a nutritional scientist's view, they are the family of compounds known as Vitamin K, or the quinones including phylloquinone (Vitamin K1) from plants and menaquinones (vitamin K2) found in fish oils and meats.
Menaquinones also are synthesized by bacteria in the human colon. A synthetic compound, called menadione, can be converted to menaquinone in body tissues. Phylloquinone, the main dietary form of the vitamin is the most biologically active form.

Vitamin K: Sources

About 10% of the Vitamin K absorbed each day comes from bacterial synthesis in the colon.

Vitamin K Food sources include:

  • Kale
  • Turnip
  • Greens
  • Parsley
  • Salad greens
  • Cabbage
  • Spinach
  • Broccoli
  • Peas
  • Brussels sprouts
  • Looseleaf lettuce
  • Asparagus
  • Kale
  • Green beans
  • Vegetable oils (soy and canola)

Vitamin K Needs (Adequate Intake)

For men, the adequate intake of Vitamin K is 120 ug/day, and for women, it is 90 ug/day.
read more: Laboratory Values for Nutritional Assessment

Functions of Vitamin K

  • Vitamin K is needed for the synthesis of blood clotting factors by the liver and the conversion of pre-prothrombin to the active blood clotting factor called prothrombin.
  • Vitamin K participates in the synthesis of bone proteins. Without vitamin K, the bones produce an abnormal protein that cannot bind to the minerals that normally form bones. An adequate intake of Vitamin K may help protect against hip fractures.

Vitamin K Deficiency

Vitamin K deficiency can occur in newborns because vitamin K stores are typically low at birth and the intestinal tracts of newborns do not yet have bacteria that can synthesize vitamin K.
This increases the risk of bleeding due to defective blood clotting: thus, newborn infants in some countries are given vitamin K injections within 6 hours of delivery.
A deficiency in older infants, children, teens, and adults is rare, a deficiency results in poor clot formation and hemorrhage.

Vitamin K Toxicity

Toxicity is not common, and no adverse effects have been reported with high intakes of vitamin K. Therefore, an Upper Level has not been established.
High doses of vitamin K can reduce the effectiveness of anticoagulant drugs used to prevent blood clotting. People taking these drugs should eat vitamin K–rich foods in moderation and keep their intakes consistent from day to day.
In conclusion, vitamin K is not just good for the body but also performs an excellent job to help in blood clotting and add the food source of the nutrient to your food today.