Understanding Vitamin K Deficiency: Symptoms, Causes, and Treatment

Overview

Vitamins are essential nutrients that are needed in small quantities for health and normal growth of the body. They cannot be synthesised in sufficient amounts by the body and must be obtained from the diet or any synthetic source. 

When a vitamin is missing in the diet, it is called a primary or dietary deficiency. If the vitamin is not efficiently absorbed by the body due to a pre-existing condition or disease, it is referred to as a secondary or conditioned deficiency.

Vitamin K is stored in the liver and other fatty tissues and need not be consumed daily. It is also found in the heart, pancreas and bone. Even with high intakes, it is metabolised quickly and excreted in urine or stool and doesn’t reach toxic levels. 

What is Vitamin K and Why is it Important?

Vitamin K is a fat-soluble vitamin that is not destroyed by cooking. It is available in 2 forms:

Phylloquinone: This is also called vitamin K1 and is the dietary form of the vitamin. Green leafy vegetables are good sources of K1. It is absorbed better by the body when it is consumed along with fat

Menaquinone: This form is referred to as vitamin K2 and is produced by gut bacteria in small quantities. K2 is also found in some animal-based foods and fermented products.

Vitamin K is an indispensable nutrient that plays a crucial role in several vital functions of the body. One of its key roles is aiding the liver in producing proteins necessary for blood clot formation. This process is essential in stopping bleeding when injuries occur. 

Vitamin K specifically assists in synthesising proteins like prothrombin, which are vital for clotting. Additionally, vitamin K also contributes to the synthesis of proteins like osteocalcin, which are crucial for maintaining healthy bone metabolism.

Symptoms of Vitamin K deficiency:

Vitamin K deficiency can prolong the clotting time of blood. While bleeding and haemorrhage are considered classic signs of vitamin K deficiency, they occur only in severe cases. People with vitamin K deficiency tend to:

• get bruised easily, develop small clots underneath the nails
• bleed spontaneously from the nose, a wound or internally in the stomach or intestines even without injury
• have weaker bones with conditions like osteopenia or osteoporosis

Bleeding in the stomach could cause vomiting of blood. Blood may also be present in the urine or stool and stools could be tarry black or dark. Vitamin K deficiency is also associated with obstructive jaundice. Women with vitamin K deficiency may have heavier periods.

Many babies do not show any warning signs of vitamin K deficiency. Therefore, It is important to watch out for life-threatening complications such as:

• bleeding at the point where the umbilical cord is cut.
• visible bruises around the baby’s head and face
• pale skin 
• prolonged bleeding after circumcision 
• haemorrhage within or around the brain with signs like increased irritability, seizures or excessive vomiting.

Causes of Vitamin K Deficiency

• In adults, vitamin K deficiency can occur due to a diet that lacks vitamin K or due to a very low-fat diet because vitamin K is best absorbed when eaten with fat.
• Vitamin K deficiency can also arise in people who have fat malabsorption syndrome. Such disorders cause inadequate fat absorption and lower the levels of available vitamin K. They include celiac disease, cystic fibrosis, cirrhosis and resection of the small intestine. 
• People who are on medications like antiseizure drugs or certain antibiotics are also at increased risk of vitamin K deficiency. Some antibiotics, when taken for a long term, interfere with the body’s production of vitamin K, while others may reduce the effectiveness of vitamin K. Bleeding due to vitamin K deficiency is often seen in people whose intestinal flora has been destroyed by antibiotics.

All babies have low levels of vitamin K at birth and carry an increased risk of vitamin K deficiency. During pregnancy, very little vitamin K crosses the placenta and reaches the foetus. Babies who are exclusively breastfed are also at risk because breast milk contains very low amounts of vitamin K. A newborn baby’s intestine does not have the necessary bacteria to synthesise vitamin K, and the liver is not yet able to utilise the available vitamin K efficiently.

How to Diagnose Vitamin K Deficiency?

A thorough medical history is essential to diagnose vitamin K deficiency, as people with certain disorders are at greater risk. One of the common tests is a coagulation test called the PT test.

Prothrombin Time (PT): Blood tests like PT can confirm vitamin K deficiency by measuring the time taken for clotting. Prothrombin is a clotting factor produced by the liver. When bleeding occurs, it changes quickly to thrombin to stop the bleeding. The PT test determines how quickly prothrombin is converted to thrombin. The normal range is between 11 and 13 seconds. Result beyond this range indicates a clotting disorder like vitamin K deficiency. 

If the clotting time improves after an injection of vitamin K, the diagnosis can be confirmed.

For people who are on anticoagulants, the PT is calculated as a number (ratio) that is compared to a standard value called the International Normalised Ratio (INR). Normal healthy individuals have an INR of 1. For a person on the anticoagulant warfarin, an ideal INR is between 2 and 3. Anything above these values indicates that the blood is too thin with a greater risk of bleeding.

Treatment of Vitamin K Deficiency: 

When vitamin K deficiency is confirmed, the treatment is as follows:

• Phytonadione (synthetic vitamin K1) is given orally or as an intravenous or intramuscular injection. The usual dose for adults is 1-25 mg. 
• A smaller dose of the drug, 1-10 mg, is given to people who are on anticoagulants. They need to maintain consistent levels of vitamin K intake.
• All newborns are given a single injection of 0.5-1 mg of vitamin K1 within an hour of birth. A higher dose is needed if the mother is on medications like anticoagulants. 
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Management of Vitamin K Deficiency

In adults, vitamin K deficiency can lead to excessive bleeding. Fortunately, in most cases, the condition can be managed and treated without further complications.

The long-term outlook for infants with vitamin K deficiency is good if it is identified early and treated promptly. 

How to Prevent Vitamin K Deficiency?

To prevent nutritional deficiency in adults, men require 120 micrograms and women need 90 micrograms of vitamin K. Some of the best sources of dietary vitamin K are:

• Green leafy vegetables like spinach, broccoli and kale
• Meat, dairy foods and eggs
• Cheese and fermented soybeans

There are also many forms of vitamin K available alone or together with calcium, magnesium or vitamin D as multivitamin supplements. 

To avoid complications, people with comorbidities should consult their doctor before taking vitamin K supplements.

FAQs

What Happens if Vitamin K is Deficient?

Vitamin K deficiency can lead to haemorrhagic disease in the newborn, with complications like excessive bleeding. It can become fatal if the bleeding occurs within or around the brain.

Adults rarely experience vitamin K deficiency. If they do, the condition can prolong clotting time, cause haemorrhages and weaken bones.

What is The Main Cause of Vitamin K Deficiency?

• In adults, vitamin K deficiency can occur due to a diet that lacks vitamin K or due to a very low-fat diet because vitamin K is best absorbed when eaten with fat. 
• It could also occur in people who have taken antibiotics for a long period because these drugs inhibit the growth of gut bacteria that synthesise vitamin K. 
• It can also be a result of disorders that decrease the production or obstruct the flow of bile, which is needed for intestinal absorption of vitamin K.
• New-born babies carry an increased risk of developing vitamin K deficiency because they have very minute quantities stored in their bodies.

What are The 4 Signs of Vitamin K Deficiency?

Excessive bleeding is the main symptom of vitamin K deficiency. It may manifest in the following ways:

• frequent bruising, small clots beneath the nails
• spontaneous bleeding from the nose, mouth, lungs, or stomach lining
• dark stool, blood in the urine
• Heavy menstrual bleeding in women

In infants, there could be:

• prolonged bleeding after the umbilical cord is cut
• bleeding after circumcision
• haemorrhage inside the brain

What is Vitamin K Deficiency Called?

In infants, vitamin K deficiency is called Vitamin K Deficiency Bleeding (VKDB). It occurs when there isn’t enough vitamin K in the baby’s body and they do not receive a vitamin K shot at birth. 

Which Fruits are High in Vitamin K?

Although fruits contain lesser amounts of vitamin K than green leafy vegetables, kiwifruit contains a decent amount of the vitamin. A single cup (180 gm) of kiwifruit provides 60% of the daily value (the approximate amount needed to prevent deficiency). Some of the following fruits also contain moderate amounts of the vitamin:

• yellow plantains
• avocados 
• blackberries
• blueberries 
• pomegranate

Who is Most at Risk for Vitamin K Deficiency?

Vitamin K deficiency is rare in adults since the diet typically provides sufficient amounts of the vitamin. It primarily affects individuals with malabsorption disorders, those on specific medications or those who have undergone weight-loss surgery.

Infants and newborn babies, particularly those who are breastfed, are at higher risk of vitamin K deficiency.