Which Vitamin Deficiency Causes Excessive Bleeding?

November 26, 2025 •

4 min read

According to the CDC, Vitamin K Deficiency Bleeding (VKDB) can be life-threatening in newborns. Understanding which vitamin deficiency causes excessive bleeding is crucial for identifying and addressing the underlying health issues related to the blood’s ability to clot effectively.

Quick Summary

Excessive bleeding is most commonly caused by a severe lack of vitamin K, which hinders the production of crucial clotting proteins. Less frequently, extreme vitamin C deficiency (scurvy) results in bleeding from weakened blood vessel walls. Certain anemias linked to vitamin B12 deficiency can also affect clotting.

Key Points

Vitamin K is key for clotting: Vitamin K deficiency is the most direct vitamin-related cause of excessive bleeding, as it prevents the liver from synthesizing essential blood clotting proteins.
Scurvy causes bleeding differently: A severe lack of vitamin C (scurvy) can cause bleeding gums and bruising by weakening blood vessel walls, not by disrupting clotting factors directly.
Newborns are at high risk: Infants are particularly susceptible to Vitamin K Deficiency Bleeding (VKDB) and are routinely given a vitamin K shot at birth for prevention.
Malabsorption is a major factor: In adults, deficiency often stems from conditions that affect vitamin absorption in the gut or liver, rather than diet alone.
B12 deficiency can contribute indirectly: A severe vitamin B12 deficiency can lead to anemia and indirectly impact clotting by affecting platelet levels.
Excessive bleeding is a serious symptom: Any instance of excessive or unexplained bleeding warrants immediate medical attention to identify the underlying cause.

The Role of Vitamin K in Blood Coagulation

Vitamin K is a fat-soluble nutrient essential for producing key proteins in the liver that are vital for blood clotting. These are known as coagulation factors, specifically II, VII, IX, and X. A deficiency in this vitamin directly impairs the body's ability to form clots, leading to a higher risk of prolonged or excessive bleeding.

Common signs of vitamin K deficiency include:

Easy bruising
Nosebleeds
Bleeding gums
Excessive bleeding from wounds or injection sites
Blood in the urine or stool
Heavy menstrual bleeding

Vitamin K Deficiency in Newborns (VKDB)

Newborns are especially vulnerable to vitamin K deficiency because only small amounts cross the placenta, and their gut bacteria (which produce some vitamin K) are not yet fully developed. This can lead to Vitamin K Deficiency Bleeding (VKDB), a serious condition that can cause life-threatening internal bleeding. To prevent VKDB, a single vitamin K injection is routinely recommended for newborns at birth.

Risk Factors for Vitamin K Deficiency in Adults

While rare in healthy adults, several factors can increase the risk of vitamin K deficiency:

Malabsorption disorders: Conditions like cystic fibrosis, celiac disease, or inflammatory bowel diseases can hinder the absorption of fat-soluble vitamins, including vitamin K.
Poor diet: An extremely low intake of leafy green vegetables, the primary dietary source of vitamin K1, can cause a deficiency over time.
Antibiotic use: Prolonged use of antibiotics can disrupt the gut bacteria responsible for synthesizing vitamin K.
Liver disease: Since clotting factors are produced in the liver, liver disorders can impact vitamin K metabolism and synthesis.
Anticoagulant medications: Drugs like warfarin interfere with vitamin K's function, which is why individuals on these medications must maintain a consistent vitamin K intake.

Vitamin C Deficiency and Bleeding (Scurvy)

Vitamin C deficiency, also known as scurvy, can cause bleeding, but the mechanism is different from that of vitamin K. Vitamin C is necessary for the synthesis of collagen, a protein that strengthens blood vessel walls and connective tissues. A severe deficiency weakens these blood vessels, making them fragile and prone to rupture, which leads to bleeding.

Symptoms of advanced vitamin C deficiency (scurvy) include:

Swollen, bleeding gums
Bruising easily
Pinpoint red or blue spots under the skin from burst blood vessels
Poor wound healing
Loosened teeth
Joint pain

Other Deficiencies and Blood-Related Issues

Vitamin B12 and Anemia

Severe vitamin B12 deficiency can cause a type of anemia where the body cannot produce enough healthy red blood cells. While not directly impacting the clotting factors like vitamin K, severe anemia can lead to a condition where the number of platelets (which help with clotting) is low. This can manifest as increased bruising and a tendency for bleeding. This is an indirect cause of bleeding compared to the direct impact of vitamin K on coagulation factors.

Comparing Bleeding Caused by Vitamin K vs. Vitamin C Deficiency


Feature	Vitamin K Deficiency	Vitamin C Deficiency (Scurvy)
Mechanism of Bleeding	Impaired production of blood clotting factors in the liver.	Weakening of blood vessel walls due to insufficient collagen production.
Associated Bleeding Symptoms	Easy bruising, nosebleeds, internal bleeding, blood in stool/urine.	Bleeding gums, easy bruising, pinpoint skin hemorrhages.
Primary Cause	Poor diet, malabsorption, liver disease, certain medications.	Long-term, inadequate intake of fresh fruits and vegetables.
Associated Non-Bleeding Symptoms	Possible bone issues.	Fatigue, joint pain, poor wound healing, hair changes.
Targeted Treatment	Vitamin K supplementation, often via injection or oral supplements.	High-dose vitamin C supplementation and dietary changes.

How to Increase Vitamin K Intake

Boosting your vitamin K levels, if deficient, often involves a combination of dietary adjustments and, in some cases, supplements. Vitamin K exists in two main forms: phylloquinone (K1) from plants and menaquinones (K2) from fermented foods and animal products.

Dietary Sources of Vitamin K

Leafy Greens: Excellent sources include kale, spinach, Swiss chard, collard greens, and mustard greens.
Vegetables: Broccoli, Brussels sprouts, and cabbage also contain good amounts of vitamin K.
Vegetable Oils: Canola and soybean oils are notable sources.
Fermented Foods: Natto (fermented soybeans) is a particularly rich source of vitamin K2.
Animal Products: Meat, eggs, and dairy also contain menaquinones (K2).

For better absorption of the fat-soluble vitamin K from plant sources, it is recommended to consume these foods with some fat.

Conclusion: When to Seek Medical Advice

While dietary changes can address nutritional deficiencies, excessive or unexplained bleeding should always be evaluated by a healthcare professional. Bleeding disorders can have various causes, and a doctor can perform tests to determine the correct diagnosis, which may include blood tests to check clotting function and vitamin levels. Prompt medical attention is vital to prevent serious complications, especially in cases of severe or internal bleeding. Always consult a professional for a proper diagnosis and treatment plan if you have concerns about excessive bleeding.

CDC Information on VKDB

Note: Medical information in this article is for informational purposes only and does not constitute professional medical advice. Always consult a healthcare provider for any health concerns.

Frequently Asked Questions

The primary vitamin deficiency that causes excessive bleeding is vitamin K deficiency. This is because vitamin K is essential for producing the proteins in the liver responsible for blood clotting.

Yes, a severe vitamin C deficiency, known as scurvy, can cause bleeding. Unlike vitamin K, it does not affect clotting factors but instead weakens the walls of blood vessels and connective tissues due to inadequate collagen synthesis, leading to bruising and bleeding gums.

Newborns are susceptible because they have limited vitamin K reserves at birth, and the bacteria in their gut that produce vitamin K have not yet been established. This increases their risk for Vitamin K Deficiency Bleeding (VKDB).

Key symptoms include easy bruising, nosebleeds, bleeding from gums or wounds, and blood found in the urine or stool. Severe cases can lead to internal bleeding.

You can increase your vitamin K intake by eating more leafy green vegetables like kale and spinach, as well as broccoli, Brussels sprouts, and fermented foods such as natto. Consuming these with some dietary fat aids absorption.

While less direct, a severe deficiency in vitamin B12 can cause anemia, which can in turn be associated with bleeding and easy bruising due to a low platelet count. This is a potential complication of the anemia itself.

You should see a doctor immediately for any unexplained or persistent bleeding, bruising, or other concerning symptoms. Excessive bleeding can have various causes, and a healthcare professional can provide a proper diagnosis and treatment plan.