Vitamin K is a nutrient whose importance is often only recognized when problems with blood clotting or bone health arise. This small vitamin plays major roles in the body; it participates in forming proteins responsible for stopping bleeding, supports calcium balance, and maintains bone strength. According to a report published on the Vinmec website, maintaining a balance in vitamin K levels is crucial, as an excess is just as risky as a deficiency.

Vitamin K is vital for liver function, helping produce clotting factors that prevent bleeding from wounds or surgeries. It is a fat-soluble vitamin, meaning it requires fat presence for effective absorption by the body.

There are two main types of vitamin K:

• Vitamin K1 (Phylloquinone): the natural form found in leafy plants such as spinach, broccoli, and celery.
• Vitamin K2 (Menaquinone): produced inside the body by beneficial gut bacteria.

In addition to these natural forms, synthetic forms are sometimes used in medical preparations but can be harmful if overused or unsupervised.

Usually, vitamin K excess does not occur from diet alone, as the body naturally eliminates excess amounts. Problems arise when supplements or injections are taken in high doses over long periods, especially when vitamin K is used to treat bleeding or aid clotting after surgeries.

This excess can disrupt blood balance by stimulating liver cells to produce large amounts of clotting proteins, increasing the risk of blood clots inside vessels. Accumulation of vitamin K may also strain the liver and kidneys.

Experts point to several symptoms that may indicate the body has exceeded normal vitamin K levels, including:

• Paleness of the skin and general fatigue due to blood cell imbalance.
• Enlarged liver and discomfort in the right side of the abdomen.
• Increased sweating and shortness of breath due to vitamin effects on the neuromuscular system.
• Swollen eyelids and skin redness due to fluid retention.
• In rare cases, hemolysis or jaundice caused by liver damage.

Any of these signs require immediate blood tests to assess vitamin and liver enzyme levels.

Vitamin K injections are given to all newborns immediately after birth to prevent brain hemorrhage, as the placenta does not transfer sufficient amounts to the fetus, and breast milk contains limited amounts. However, this dose is carefully calculated.

The report warns against giving additional doses without medical supervision, as excessive amounts at this critical age may cause blood cell damage, severe jaundice, or even cerebral palsy in extreme cases.

Some medications—especially anticoagulants like warfarin—work by inhibiting vitamin K’s effect in the body to maintain blood fluidity. Therefore, consuming excessive vitamin K through food or supplements may reduce the drug’s effectiveness.

Patients on these medications are advised to maintain a consistent diet and avoid excessive intake of vitamin K-rich foods such as spinach, cabbage, and parsley, with regular monitoring of blood clotting levels.

The best way to avoid vitamin K deficiency or excess is nutritional balance. The recommended daily intake varies by age and gender but generally ranges between 90 and 120 micrograms for adults.

Foods rich in vitamin K include:

• Leafy vegetables (spinach, parsley, cabbage).
• Vegetable oils, such as olive and soybean oils.
• Eggs and some dried fruits.

Supplement intake should only be under medical supervision.

Deficiency leads to impaired blood clotting, causing frequent bleeding in gums, nose, or under the skin, and severe cases may develop internal bleeding.

This deficiency is rare in healthy adults but common among those with digestive problems or long-term antibiotic use that kills beneficial gut bacteria responsible for producing vitamin K.

Prevention of vitamin K excess depends on nutritional awareness and regular medical monitoring, especially for patients taking anticoagulants or multiple supplements.

• Eat a varied diet including fresh vegetables and fruits.
• Avoid excessive supplements unless prescribed by a doctor.
• Monitor liver function in routine tests.
• Consult a doctor immediately if any abnormal symptoms appear, such as yellowing of the eyes or changes in urine color.