Vitamin K deficiency
Key facts
- Vitamin K deficiency is when you don’t have enough vitamin K.
- Vitamin K is found in many foods, and also made by bacteria in your gut.
- Not having enough vitamin K in your body can make you bruise or bleed more easily.
- A blood test can check for vitamin K deficiency.
- If you don’t have enough vitamin K, your doctor will prescribe a vitamin K supplement.
What is vitamin K deficiency?
Vitamin K deficiency is when you don’t have enough vitamin K. This can cause bleeding problems, as vitamin K helps your blood to clot.
What is vitamin K?
Vitamin K is a fat-soluble vitamin. It helps your blood to clot and is also important for healthy bones.
Vitamin K is found in foods that we eat. It’s also made by the bacteria in your gut.
Vitamin K is found in your:
Vitamin K is broken down quickly and removed from your body in urine (wee) or faeces (poo).
What are the symptoms of vitamin K deficiency?
The most common signs of vitamin K deficiency are:
- your blood taking longer to clot
- bleeding
- bone conditions — osteopaenia or osteoporosis
CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.
What causes vitamin K deficiency?
Vitamin K deficiency is rare in healthy adults.
Adults with vitamin K deficiency may have a health condition, such as:
- cholestasis
- coeliac disease
- cystic fibrosis
- small bowel disease
You can also get vitamin K deficiency by taking medicines that block vitamin K metabolism, such as antibiotics.
It’s rare for adults to have vitamin K deficiency due to their diet alone.
Newborn babies can have a vitamin K deficiency. This is because vitamin K does not cross the placenta. To stop this from happening, a vitamin K injection is offered for all babies at birth.
When should I see my doctor?
You should see your doctor if you bruise easily or have bleeding sores or scabs that don’t heal. This could be a sign of vitamin K deficiency.
FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.
How is vitamin K deficiency diagnosed?
Your doctor will ask you about your symptoms and medical history. They will ask about any medicines you take.
If your doctor suspects you have vitamin K deficiency, they will organise for you to have some blood tests.
ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.
How is vitamin K deficiency treated?
If you have vitamin K deficiency, your doctor will prescribe a vitamin K supplement. This may be given by mouth or through an intravenous (IV) drip.
It may also be helpful to see a dietitian. They can help check that your diet has foods containing vitamin K.
Complications of vitamin K deficiency
Vitamin K deficiency can lead to:
- significant bleeding
- poor bone development
- osteoporosis
- increased cardiovascular (heart) disease
Can vitamin K deficiency be prevented?
Eating foods containing vitamin K can help prevent vitamin K deficiency.
The best dietary sources of vitamin K are dark green leafy vegetables like:
- broccoli
- Brussels sprouts
- cabbage
- kale
- lettuce
- spinach
Other good sources of vitamin K are:
- fermented food and drinks
- cheese
- eggs
- nuts
- soybeans
- vegetable oils (especially soybean and canola oils)
- yoghurt
It’s best to eat vitamin K foods with some fat to help improve absorption.
Resources and support
Learn more about babies and vitamin K.
See the Australian Guide to Healthy Eating.
The Dietitians Australia website allows you to search for an Accredited Practising Dietitian.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: April 2024
