Vitamin K Level Determination: A Clinical Situation That Revealed a Hidden Problem

Case: bruises for no reason

Anna, 43 years old, went to the doctor with complaints of frequent bruising on the legs and arms, which appear without strokes. She was also worried about bleeding gums while brushing teeth. Complete blood count — no changes. Clotting time is prolonged. The doctor prescribed blood test for vitamin K levels.

What did the analysis show?

Vitamin K1 (phylloquinone) level — 0.08 ng/ml, that below the lower limit of normal. Additionally, it turned out that Anna does not eat green vegetables and has been taking a tetracycline antibiotic for several months after chronic sinusitis.

What does this mean?

Vitamin K is key for synthesis of blood clotting factors. Its deficiency may remain unnoticed for years, but with a combination of diet, medication, and gut condition leads to bleeding and the threat of hemorrhage.

What do you need to know about vitamin K?

• Vitamin K1 comes with green vegetables (spinach, broccoli, lettuce).

• Vitamin K2 (menaquinone) is produced by bacteria in the intestine.

• He does not accumulate in large quantities, therefore, deficiency develops rapidly when absorption or synthesis is impaired.

Who is most at risk of having a deficiency?

• People on high-fat diets or poor nutrition

• Patients with pathology of the liver, biliary tract

• Those who accept antibiotics for more than 10 days

• People who use anticoagulants (e.g., warfarin)

• Newborns, who were not given vitamin K prophylactically

How to check the level?

The analysis requires venous blood sampling. on an empty stomach. It is advisable to combine it with coagulogram or INR, to assess the functional impact of the deficit.

Normal values of phylloquinone (vitamin K1):
Adults — 0.1–2.2 ng/ml
Newborns — <0.1 (without prophylaxis — always reduced)

What to do if the level is low?

• Enter dietary changes — eat more broccoli, spinach, cabbage, soy, parsley.

• Avoid excessive use of antibiotics, especially without probiotics.

• If necessary - prescribing vitamin K in the form of a drug or complex.

• If you are taking anticoagulants — do not change your diet abruptly without consulting your doctor.

Doctor's comment

“We often underestimate the role of vitamin K. Unlike iron or vitamin D, its deficiency does not have classic symptoms, but it increases the risk unexpected bleeding, especially in patients with chronic liver disease or on long-term treatment. This is a marker that should be paid attention to even in a routine examination.”

How is Anna doing?

After correcting the diet and prescribing vitamin K1 (10 mg/week), the level stabilized after just 2 weeks. The bruises disappeared, blood clotting normalized., and the doctor advised to repeat the control in 3 months - in dynamics.