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Vitamin K (Phylloquinone) - Deficiency Risk and Symptoms

2 min read

Nutrient Name

Vitamin K - also known as Phylloquinone. It is best known for its role in helping blood to clot (‘coagulate’) properly. The ‘K’ comes from its German name, ‘Koagulationsvitamin’.

Vitamin K occurs naturally in two forms:

  1. Vitamin K1 (phylloquinone) is found in plants.
  2. Vitamin K2 is the term for a group of compounds called ‘menaquinones,’ which can be found mainly in dairy products.

Potential for deficiency


Vitamin K deficiency in the general population is relatively uncommon and is not a major health problem. 

Babies are born without any bacteria in their intestines and do not get enough vitamin K from breast milk to tide them over until their bodies are able to make it. In the UK, many other European countries and the United States, all newborns receive Vitamin K, often as an injection, just after delivery to prevent the possibility of any serious blood disorders.

Health problems that may lead to Vitamin K deficiency include liver disease, gallbladder or biliary disease and Crohn's disease.

What does Vitamin K do?

Vitamin K helps your blood to clot (coagulate), maintain healthy bones and help keep blood vessels functioning properly.

Vitamin K is needed for proper use of calcium in bones. Higher Vitamin K intake has been associated with greater bone density, while low Vitamin K intake has been found in elderly individuals with osteoporosis. There is increasing evidence that Vitamin K improves bone health and reduces risk of bone fractures, particularly in postmenopausal women who are at risk for osteoporosis

The European Food Safety Authority (EFSA) confirms that clear health benefits have been established for the dietary intake of Vitamin K in contributing to:

  • maintenance of normal bone
  • normal blood coagulation

Food Sources

The richest food source of Vitamin K is green leafy vegetables such as spinach, broccoli, brussels sprouts, cabbage and lettuce. Good sources include oats, potatoes, tomatoes, asparagus and butter. Important sources of Vitamin K2 are dairy products like cheese.

No adverse affects from consumption of Vitamin K have been reported.

Symptoms of deficiency

Vitamin K deficiency can lead to excessive bleeding.

Newborn infants has a well-established risk of vitamin K deficiency, which may result in bleeding within the skull in the first weeks of life

A healthy balanced diet is the best way to consume all the nutrients we need. Sometimes however this isn't possible and then supplements can help. This article isn't intended to replace medical advice. Please consult your healthcare professional before trying any supplements or herbal medicines.