VITAMIN K

Vitamin K is an essential micronutrient belonging to the family of fat-soluble vitamins. It exists in two forms – phylloquinone and menaquinones.

Vitamin K helps in wound healing by its blood clotting mechanisms.

There is also evidence that vitamin K plays a vital role in bone metabolism and regulating blood calcium levels.

Why is vitamin k essential to the human body?

• Blood coagulation: The primary function of vitamin K in the body is the maintenance of normal blood coagulation.
• Synthesis of proteins: Vitamin K functions as a coenzyme for the synthesis of proteins involved in hemostasis (blood clotting) and bone metabolism.
• Vitamin K is also involved in the production of osteocalcin, a protein in the bone that helps prevent the weakening of bones. Studies suggest, intake of this vitamin can reduce incidence of hip fracture and low bone density.
• Heart health: Vitamin k plays a vital role in cardiac health. It prevents mineralization, thereby lowering blood pressure. An adequate amount of vitamin k enables the heart to pump blood freely through the body.

What are the signs and symptoms of vitamin k deficiency?

Vitamin k deficiency may present with any of the following signs/symptoms :

• Easy bruising
• Oozing blood from nostrils
• Bleeding gums
• Excessive menstrual bleeding
• Haemorrhage from the gastrointestinal tract
• Blood in urine and/or stools.
• Uncontrolled bleeding from cuts, wounds, punctures or sites of injection, etc. Or poor wound healing.
• Bleeding underneath nails

What is the daily requirement of vitamin k?

Recommended dietary intakes have not been suggested for different age groups or gender. The safe levels of intake as suggested are 80 mcg for adult males and 65 mcg for adult females. The recommended nutrient intake for vitamin K, as suggested by FAO/WHO is:

What are the food sources of vitamin k?

Phylloquinone is present primarily in green leafy vegetables and is the main dietary form of vitamin K. Vegetables such as broccoli, spinach, green peas, cabbage, and green beans.

Fruits like kiwi and avocado are rich sources of vitamin k.

Menaquinones, which are predominantly of bacterial origin. They are present in modest amounts in various animal-based and fermented foods like fermented soybeans, meat, cheese, and egg.

The bacteria in the human gut also produce menaquinones.

Can excess vitamin k cause toxicity?

Vitamin K is found throughout the body including the liver, brain, heart, pancreas, and bone. It is broken down very quickly and excreted in urine or stool. Hence, even at high intakes it rarely reaches toxic levels in the body.

The toxicity of vitamin K manifests with symptoms like jaundice, hyperbilirubinemia, kernicterus in infants, and hemolytic anemia.

Interesting facts

• Warfarin and some anticoagulants antagonize the activity of vitamin K and prothrombin. For this reason, patients who are taking anticoagulants are advised to maintain consistent intake of vitamin K.
• Antibiotic medicines may destroy vitamin-K-producing bacteria in the gut. This may potentially decrease vitamin K levels in the body. Patients on long-term antibiotics with a poor appetite may benefit with Vitamin K supplements.