Vitamin K is a fat-soluble micronutrient which is essential for making proteins for healthy bone and tissues. It synthesises the protein responsible for blood clotting and protect against severe bleeding. The proper functioning of vitamin K in human body depends upon the adequacy of vitamin E in our system which regulates the uses of vitamin K. Small quantity of vitamin K is also formed by bacteria in small intestine however, major source of vitamin K are green leafy vegetables and animal derived products (1, 2).

Types of Vitamin K

There are 2 types of  Vitamin K (2, 3):

  • Vitamin K1: It is known and phylloquinone and is easily obtained from green leafy vegetables.
  • Vitamin K2: It is called as menaquinone and can be obtained from animal-derived food products like meat, cheese and eggs.

What is Vitamin K Deficiency?

Vitamin K deficiency is the health condition caused by prolonged deprivation of Vitamin K. It may be caused by inadequate intake of Vitamin K rich diet, rapid metabolism, excessive excretion and malabsorption due preexisting health conditions like gastrointestinal disorders. GI disorders affects the presence and reproduction of good bacteria which are responsible for internal production of vitamin K (2). 

Functions of Vitamin K

Vitamin K functions as coenzymes for vitamin K dependent carboxylase and enzymes responsible for the formation of protein which helps in haemostasis (blood clotting), bone metabolism and other necessary functions. The vitamin K based protein responsible for blood clotting is known as prothrombin (2).

Causes of Vitamin K Deficiency

The condition of Vitamin K deficiency can be developed due to various factors. Some of the major cause have been illustrated below:

  • Inadequate Diet: The most common cause of Vitamin K deficiency is vitamin deficit diet. We often end up consuming foods which are poor in essential vitamins and minerals such as Vitamin K. Green leafy vegetables and animal derived food products are rich source of Vitamin K however, these food items are not adequately available to lower income group.  
  • GI Disorders: Vitamin K is soluble in fat; hence it gets stored in liver for future use. Presence of gastrointestinal disorders interferes with the absorption of Vitamin K and unfavourable conditions for the vitamin K generating bacteria resides in small intestine. These factors will lead to prolonged vitamin C deficiency.
  • Vitamin E Deficiency: Vitamin E regulates the utilisation of vitamin K; its deficiency may lead to malabsorption and imbalance of vitamin K in our body.
  • Newborn Babies: Babies are bon with vitamin K deficiency, within few weeks of born they need to be treated with vitamin K supplements otherwise it may cause bleeding in the umbilicus, gastrointestinal tract, skin, nose, or other sites (4). 

Symptoms of Vitamin K Deficiency 

The common symptoms of Vitamin K deficiency include (5):

  • Easy bruising
  • Oozing from nose or gums
  • Excessive bleeding from wounds, punctures, and injection or surgical sites
  • Heavy menstrual periods
  • Bleeding from the gastrointestinal (GI) tract
  • Blood in the urine and/or stool.

Health Risks due to Vitamin K Deficiency

Vitamin K deficiency posses several health risks. Some of the health risks are illustrated below (4):

  • Cardiovascular Diseases (CVD): Vascular calcification is the major cause of heart diseases. Matrix Gla-protein (MGP) which is vitamin-K based protein plays vital role in prevention of calcification.  Vitamin K deficiency may lead to improper regulation of MGP and results in coronary heart disease.
  • Osteoporosis: It is mainly caused by the deficiency of calcium and vitamin D in the body however, vitamin K acts as co factor for the protein osteocalcin which is responsible for the bone mineral density.  Vitamin K deficiency may lead to fragile and porous bone.
  • Internal Bleeding: Vitamin K deficiency may result in bleeding from gastrointestinal tracts, eyes, gums, heavy menstruation period. It is primarily caused by the inadequacy of vitamin K based protein prothrombin.  

Tests for Vitamin K Deficiency

The test for vitamin K deficiency is very rarely used. It’s often identified due to heavy bleeding in GI tracts, nose, gums and during urine and stool. In general, there would be any preventive measure required for the test however, individual should stop taking medications which might interfere with test results. 

  • Prothrombin Time (PT): The primary used test for the identification of vitamin K is prothrombin time. If the result of test is prolonged, then vitamin K supplements are provided and it the condition of the patient improve it may indicate the condition of vitamin K deficiency.

Remedies of Vitamin K Deficiency 

  • Vitamin K Supplements: If you are diagnosed with severe Vitamin K deficiency, you should consider medical supplements under supervision of doctors. As higher Vitamin K may lead to deadly health condition.
  • Vitamin K Rich Diet: Vitamin K rich food items will help in minimising the Vitamin K deficiency. Some of the Vitamin K rich food items are like includes leafy veggies, Fish, liver, meat, eggs, cheese, dairy products, soybean, pumpkin, brussels sprout, broccoli, cabbage, cauliflower.
  • Vitamin E Rich Diet: Vitamin E is responsible for the utilisation of Vitamin K. Some of the Vitamin E rich food items are like includes Wheat germ oil, sunflower, safflower, soybean oil, sunflower seeds, almonds, peanuts, peanut butter, spinach, pumpkin, red bell pepper, asparagus, mango, avocado.
  • Fortified Food Items: Rich source of Vitamin K are green leafy vegetables and animal derived products. Agricultural lands lack in Vitamin K concentration will produce foots with relatively low concentration of phylloquinone. Such situation can be overcome by providing fortified seeds.  

Prevention of Vitamin K Deficiency

It is often said that “Prevention is better than Cure” and indeed this is very much true with reference to micronutrient deficiencies. Vitamin K deficiency can be prevented through consumption of Vitamin K rich diet.

Food items rich in Vitamin K (4):

  • Collards
  • Turnip
  • Spinach
  • Broccoli
  • Soybeans
  • Carrot juice
  • Soybean oil
  • Pumpkin
  • Pomegranate 
  • Okra
  • Blueberries
  • Chicken
  • Grapes
  • Olive oil
  • Figs
  • Chicken 
  • Cheese
  • Milk
  • Salmon
  • Shrimp

Ideally, we should consume adequate quantity of vegetables fruits and animal derived products which are the major source of Vitamin K in our diet. 

Adequate Intake (>19 yrs.):

The recommended intake of Vitamin K varies with age however the recommended daily intake of Vitamin K for an adult is 90-120 mcg. 

Vitamin K is fat-soluble vitamin essential for regulating severe bleeding, bone metabolism and other necessary body functions. It plays vital role in providing protection against osteoporosis and cardiovascular disease and internal bleeding especially in newborn. 

Although Vitamin K deficiency has several ill effects, it can be treated with the right consultation and medical supplements as prescribed by medical experts. The best possible way to avoid these complications by consuming adequate amount of Vitamin K as per RDA through various Vitamin K rich diet.