Nutrition and Diet: What Vitamin Deficiency Causes Bleeding and Bruising?

October 13, 2025 •

5 min read

According to research from the National Institutes of Health, clinically significant vitamin K deficiency is rare in healthy adults but is a concern for infants and individuals with certain health conditions. This can lead to uncontrolled bleeding and bruising, highlighting precisely what vitamin deficiency causes bleeding and bruising and why it is so critical for proper nutrition.

Quick Summary

Severe lack of vitamins K or C can lead to bleeding and bruising issues. Vitamin K is essential for blood clotting, while vitamin C helps form collagen, which supports blood vessel integrity. Dietary choices, malabsorption, and specific health conditions increase risk.

Key Points

Vitamin K is Vital for Blood Clotting: Deficiency in Vitamin K impairs the body's ability to produce necessary clotting factors, leading to excessive bleeding and easy bruising.
Vitamin C Strengthens Blood Vessels: A severe lack of Vitamin C causes scurvy, a disease where compromised collagen leads to weakened, fragile blood vessels that bleed easily.
Newborns are High-Risk for Vitamin K Deficiency: Due to low placental transfer and minimal levels in breast milk, newborns are highly susceptible and routinely receive a vitamin K shot.
Malabsorption and Medications Increase Risk: Conditions that prevent fat absorption, like celiac disease, and certain medications, including antibiotics and anticoagulants, can lead to Vitamin K deficiency.
Diagnosis is Key for Treatment: Unexplained bruising and bleeding warrant a medical evaluation, with blood tests like PT/INR helping to diagnose Vitamin K deficiency.
Dietary Changes and Supplements Correct Deficiencies: Both vitamin K and C deficiencies are treatable with targeted dietary changes and, in some cases, supplements, leading to a quick resolution of symptoms.
Prevention is Achieved Through a Balanced Diet: A diet rich in a variety of fruits and green leafy vegetables is the most effective way to prevent deficiencies in both vitamins.

The Crucial Role of Vitamins in Blood Health

Bleeding and bruising are common occurrences, often resulting from minor bumps or injuries. However, when they happen without a clear cause or become frequent, they can be a sign of an underlying nutritional issue. Vitamins are essential micronutrients that play critical roles in various bodily functions, including the integrity of blood vessels and the complex process of blood clotting. Deficiencies in specific vitamins, most notably K and C, can compromise these processes, leading to an increased risk of hemorrhage (bleeding) and easy bruising. A balanced diet is therefore paramount for maintaining proper blood and vascular health.

Vitamin K Deficiency and Impaired Blood Clotting

How Vitamin K Supports Clotting

Vitamin K, a fat-soluble vitamin, is best known for its vital role in blood coagulation, or clotting. It is necessary for the liver to produce several key proteins, known as clotting factors (specifically factors II, VII, IX, and X). Without sufficient vitamin K, these factors are not synthesized correctly, and the blood's ability to clot is severely compromised. This can result in excessive bleeding from wounds, internal hemorrhaging, and easy bruising.

Signs of Vitamin K Deficiency

The symptoms of vitamin K deficiency can be subtle at first but may escalate to life-threatening issues, especially in newborns. Signs include:

Easy bruising
Excessive bleeding from minor wounds, injections, or surgical incisions
Nosebleeds and bleeding from the gums
Blood in the urine or stool, which may appear dark and tarry
Heavy menstrual bleeding in women

Who is at Risk for Vitamin K Deficiency?

While rare in healthy adults with a balanced diet, certain groups and conditions increase the risk. Newborn infants are particularly susceptible because vitamin K does not cross the placenta well, and breast milk contains very low levels. This is why a vitamin K injection is routinely administered to newborns to prevent life-threatening bleeding. Other risk factors include:

Malabsorption disorders: Conditions like celiac disease, cystic fibrosis, and other small bowel diseases can interfere with the absorption of fat-soluble vitamins, including vitamin K.
Medications: Long-term use of antibiotics can destroy the gut bacteria that produce vitamin K. Anticoagulant drugs like warfarin also work by blocking vitamin K activity.
Poor diet: An extremely restrictive diet, or one lacking in green leafy vegetables, can lead to deficiency.
Liver disorders: The liver is where clotting factors are produced, so liver disease can impair their synthesis even if vitamin K intake is adequate.

Vitamin C Deficiency and Compromised Vessel Walls

The Link Between Vitamin C and Collagen

Vitamin C (ascorbic acid) is a water-soluble vitamin essential for the synthesis of collagen, a key protein that forms the structure of connective tissues, including those in blood vessel walls. A severe lack of vitamin C, leading to the disease known as scurvy, results in weak blood vessel walls that easily break, causing bleeding and bruising. The integrity of skin, gums, and other tissues depends heavily on adequate vitamin C levels.

Symptoms of Scurvy

While rare in modern society, scurvy can manifest after several months of insufficient vitamin C intake. Its symptoms are distinct and include:

Swollen, spongy, and bleeding gums
Easy bruising and small red or blue skin spots (petechiae)
Dry, rough, or scaly skin and coiled body hair
Poor wound healing and the re-opening of old wounds
Joint and muscle pain
General weakness, fatigue, and irritability

Good Dietary Sources of Vitamin C

Since the body doesn't store large amounts of vitamin C, regular dietary intake is vital. The good news is that many common foods are excellent sources. Some of the best include:

Fruits: Oranges, strawberries, kiwi, cantaloupe, and papaya
Vegetables: Bell peppers (especially red and yellow), broccoli, Brussels sprouts, kale, and tomatoes

A Comparison of Vitamin K and Vitamin C Deficiencies


Feature	Vitamin K Deficiency	Vitamin C Deficiency (Scurvy)
Primary Function	Produces clotting factors for blood coagulation.	Synthesizes collagen for connective tissue, including blood vessels.
Symptom Cause	Inability of blood to form clots effectively.	Fragile and weak blood vessel walls.
Key Symptoms	Easy bruising, excessive bleeding, hemorrhage.	Bleeding gums, skin spots (petechiae), rough skin, joint pain.
Associated Bleeding	Can range from mild bruising to life-threatening internal hemorrhage.	Typically presents as mucosal bleeding (gums) and widespread skin bruising.
Primary Risk Groups	Newborns, individuals with malabsorption disorders, those on specific medications.	People with poor dietary habits lacking fresh fruits and vegetables.
Food Sources	Green leafy vegetables, vegetable oils, fermented foods.	Citrus fruits, berries, peppers, broccoli.

Diagnosis and Treatment of Deficiencies

If you experience unexplained bleeding or bruising, it is important to consult a healthcare professional. A thorough medical history, including dietary habits, is the first step. Blood tests can confirm a diagnosis. For vitamin K deficiency, a prothrombin time (PT) test is used to measure how long it takes for blood to clot. For vitamin C, a diagnosis is often based on symptoms and dietary history, with confirmation coming from a rapid improvement after supplementation. Treatment for both deficiencies is straightforward and effective.

Vitamin K: Treatment typically involves oral or injectable vitamin K supplements (phytonadione). In addition, addressing any underlying malabsorption issue and adjusting medications that interfere with vitamin K are critical.
Vitamin C: Scurvy is treated with high doses of oral or intravenous vitamin C. Symptoms of fatigue and pain often improve within 24-72 hours, while other signs like bruising and gum healing take longer to resolve. Long-term prevention involves incorporating vitamin C-rich foods into the daily diet.

Conclusion: Preventing Bleeding and Bruising Through a Balanced Diet

Unexplained bleeding and bruising are not something to be ignored. While not always linked to a nutritional issue, deficiencies in vitamins K and C are well-documented causes that can lead to serious health complications if left untreated. A balanced diet rich in a variety of fruits and vegetables is the best preventative strategy. Regular checkups with a doctor, especially for individuals with risk factors like malabsorption or certain medical conditions, are also key to early detection and treatment of any deficiency. A consistent, diverse nutrient intake ensures the body has all the tools it needs to maintain proper blood clotting and vascular integrity.

For more dietary information, a helpful resource is the Harvard Health Publishing article on how diet affects overall vitamin and mineral intake.

A Focus on Nutrient-Rich Diets for Prevention

Beyond treating a diagnosed deficiency, focusing on a nutrient-dense diet is the cornerstone of long-term prevention. Combining sources of vitamin K from leafy greens with healthy fats (like those found in olive oil or nuts) can improve absorption. For vitamin C, since it is water-soluble and can be destroyed by heat, consuming a mix of both raw and lightly cooked fruits and vegetables is recommended. Simple diet swaps, like having a salad with spinach for lunch or adding berries to your breakfast, can significantly boost your intake of these vital nutrients and keep bleeding and bruising issues at bay.

Frequently Asked Questions

Deficiencies in both Vitamin K and Vitamin C can cause bleeding and bruising. Vitamin K deficiency impairs blood clotting, while severe Vitamin C deficiency (scurvy) weakens blood vessel walls.

Newborns have low vitamin K reserves at birth because only small amounts pass through the placenta from the mother. Additionally, breast milk contains very little vitamin K, increasing the risk, which is why a vitamin K shot is recommended at birth.

Scurvy is a disease caused by a severe, long-term Vitamin C deficiency. Vitamin C is needed to produce collagen, which gives structure to blood vessels. Without it, the vessels become fragile and break easily, causing bleeding and bruising.

Symptoms of vitamin K deficiency include easy bruising, excessive bleeding from minor cuts, nosebleeds, and blood in the urine or stool. In severe cases, internal hemorrhage can occur.

A doctor can diagnose vitamin K deficiency by evaluating your symptoms and medical history. A blood test, such as a prothrombin time (PT) test, measures how long it takes for your blood to clot and can confirm the diagnosis.

Good sources of Vitamin K include green leafy vegetables like kale and spinach, as well as broccoli and vegetable oils. Excellent sources of Vitamin C are citrus fruits, strawberries, bell peppers, and broccoli.

Yes, some medications can interfere with vitamin K metabolism, leading to bleeding issues. This includes long-term use of certain antibiotics and anticoagulant drugs like warfarin, which specifically block vitamin K's activity.

If you notice frequent or unexplained bleeding and bruising, you should consult a healthcare professional. They can conduct tests to determine the cause, which may be a vitamin deficiency or another medical condition.