Understanding Vitamin K: Sources, Deficiency, and Excess

Sources, Deficiency, and Excess

Vitamin K plays a crucial role in blood clotting and bone health. While deficiency in this vitamin can lead to severe health issues, excess intake is rare but can also pose risks. Here’s a comprehensive overview of vitamin K, its sources, symptoms of deficiency, and potential hazards of excess consumption.

Sources of Vitamin K:

The primary dietary sources of vitamin K1 are green leafy vegetables such as spinach, kale, lettuce, broccoli, and parsley. Additionally, oils like canola oil, soybean oil, and olive oil are good sources. Vitamin K2 is synthesized by bacteria in the intestines and can be found in animal-derived products like poultry liver, chicken, beef, egg yolks, cheese, and fish.

Causes of Vitamin K Deficiency:

Vitamin K deficiency can occur due to serious intestinal and liver diseases, prolonged antibiotic therapy, anticoagulant and anti-epileptic drug use, and certain conditions like nutrient absorption disorders, celiac disease, cystic fibrosis, or chronic pancreatitis. Poor dietary intake, especially of green leafy vegetables, is also a common cause of vitamin K deficiency.

Symptoms of Vitamin K Deficiency:

Symptoms of vitamin K deficiency include abnormal blood clotting and bleeding, slow wound healing, prolonged and heavy menstrual periods in women, decreased blood mass, easy bruising, vascular calcification, susceptibility to infections, abnormal bone calcification, bleeding from mucous membranes (nose or gastrointestinal tract), and diarrhea.

Diagnosis of Vitamin K Deficiency:

Diagnosis of vitamin deficiencies typically involves blood tests to measure vitamin and mineral levels. Vitamin K deficiency can be diagnosed by measuring INR (International Normalized Ratio), which reflects the clotting protein’s clotting period.

Excess Intake of Vitamin K:

Excessive intake of vitamin K is rare but can lead to health issues and disrupt body balance. Symptoms of excess vitamin K intake include excessive sweating, feeling hot, anemia, heart pain, liver dysfunction and pain, hemolysis (destruction of red blood cells), and in infants, tissue necrosis and brain damage.


While vitamin K is essential for health, both deficiency and excess intake can have adverse effects. It’s crucial to maintain a balanced intake of vitamin K through a varied diet rich in green leafy vegetables and to avoid excessive supplementation unless prescribed by a healthcare professional. Regular monitoring of vitamin levels and prompt medical attention in case of symptoms is essential for maintaining optimal health.