Vitamin K plays a key role in blood clotting, wound healing and healthy bones.

What are its health benefits?

Bacteria in your colon manufacture vitamin K. It’s then absorbed back into your bloodstream and put to work.

Its other benefits include:

  • Helping relieve menstrual pain
  • To reduce the nausea and vomiting of pregnancy
  • Studies suggest that vitamin K also protects against liver and prostate cancers.

Because your body makes plenty of its own, vitamin K is hardly ever found in supplements. Only those who’ve had large sections of their bowel removed, or people with digestive absorption problems need extra vitamin K (also known as menaquinone or phylloquinone).

Do you have a deficiency?

While vitamin K deficiencies are rare in adults, they are common in newborn infants. A vitamin K injection for newborns is standard.

A deficiency is only likely if you’re taking high doses of vitamins A and/or vitamin E, as these inhibit the uptake of K. Vitamin K deficiency symptoms include easy bruising, poor blood clotting, osteoporosis and heart disease. Elderly people with a deficiency may be more likely to sustain hip fractures during falls.

Vitamin K is also used to counteract an overdose of the blood thinning medication warfarin.

Find it in these foods

While green leafy vegetables such as broccoli and spinach are the best sources of vitamin K, other good vitamin K sources include:

  • Cabbage
  • Turnip greens
  • Spinach
  • Dark lettuce
  • Beans and soybeans
  • Strawberries
  • Milk
  • Yoghurt
  • Meat
  • Eggs
  • Green tea

Recommended dietary allowance (RDA)

A typical vitamin K dose for adults is 90 mcg daily. However, consult with your Clicks pharmacist first regarding the right dosage of daily oral supplements to make up for a vitamin K deficiency.

Know the overdose risks

While toxicity is very rare in adults, too much can cause liver damage and jaundice in children. It may also cause a type of anaemia, known as haemolytic anaemia.

People taking prescription blood thinning medication, like warfarin, which intentionally interferes with the role of vitamin K, need to monitor their dietary intake of vitamin K foods closely. 

Ensure you discuss dietary supplementation with your Clicks pharmacist to avoid the potential for side effects and adverse interactions with medications.

The accuracy of this information was checked and approved by Clicks' pharmacist Waheed Abdurahman in February 2015