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Vitamin K

Vitamin K

Vitamin K is sometimes dubbed the ‘clotting vitamin’ because without it our blood cannot clot. Blood clotting is essential for wound healing. Without vitamin K we would carry on bleeding even after a minor injury.

Where do I find vitamin K?

  • We get vitamin K from the food we eat. Good sources include brussels sprouts, broccoli, cauliflower, cabbage, green tea and dark green leafy vegetables such as spinach and kale.
  • Vitamin K is also found in vegetable oils and cereals and in smaller amounts in meat, eggs, fish and dairy foods.
  • According to NHS Choices, adults need approximately 0.001mg a day of vitamin K for each kilogram of their body weight. So if you weight 65kg you would need 0.065mg daily.
  • Newborn babies and infants are at risk of vitamin K deficiency which could lead to life-threatening bleeding in the first weeks of life. For this reason newborns in the UK are given a vitamin K injection (or oral dose) shortly after birth.

Why do I need vitamin K?

Vitamin K is needed for blood clotting - which is an essential part of wound healing. There is also growing evidence to suggest that vitamin K helps carry calcium throughout the body and may therefore assist in helping us maintain strong bones.

How will I know if I am lacking in vitamin K?

Most people get all their vitamin K requirements through eating a balanced diet. Any excess is stored in the liver for future use. A vitamin K deficiency is extremely rare but may occur if the body can’t absorb the vitamin from the stomach and intestines. A deficiency will mean you are more prone to bleeding and bruising.

Can vitamin K ever be harmful?

There is insufficient evidence to show the long-term impact of consuming high doses of vitamin K. The Department of Health advises that 1mg or less per day is unlikely to cause any harm. If you are taking blood thinning drugs (such as warfarin or aspirin) you may need to limit your vitamin K intake.