What Vitamin Deficiency Causes Blood Bruises? An In-Depth Look

November 15, 2025 •

3 min read

While not common in developed nations, severe vitamin C deficiency, known as scurvy, is a well-established cause of easy bruising and other bleeding symptoms. However, it is not the only nutritional culprit, as a lack of vitamin K also plays a critical role in blood-related issues.

Quick Summary

Easy bruising can indicate a vitamin deficiency, with vitamins C and K being the most common causes. Vitamin C strengthens blood vessels, while vitamin K is essential for proper blood clotting.

Key Points

Vitamin C Deficiency: A lack of vitamin C weakens blood vessels by hindering collagen production, leading to easy bruising and bleeding gums.
Vitamin K Deficiency: Insufficient vitamin K impairs the blood's ability to clot properly due to its role in creating clotting proteins.
Scurvy: The severe form of vitamin C deficiency is called scurvy and is characterized by easy bruising and poor wound healing.
Newborns at Risk: Newborns are particularly vulnerable to vitamin K deficiency and are often given a prophylactic injection at birth to prevent a bleeding disorder called VKDB.
Other Causes: Factors like aging, certain medications (especially blood thinners), liver disease, and bleeding disorders can also cause easy bruising.
Dietary Sources: To prevent deficiencies, increase your intake of leafy greens (for Vitamin K) and citrus fruits (for Vitamin C).
When to See a Doctor: Persistent, unexplained, or widespread bruising, especially with other bleeding symptoms, warrants a medical evaluation.

Bruising, also known as a contusion, is a common occurrence resulting from damage to small blood vessels called capillaries under the skin. Normally, this happens after a physical impact, causing blood to leak into the surrounding tissue and leading to the characteristic discoloration. For some individuals, however, bruises appear with little to no explanation, suggesting a potential underlying issue. While factors like aging and certain medications can cause easy bruising, a nutritional deficiency is a notable cause. The two primary vitamins linked to blood bruises are Vitamin C and Vitamin K, each affecting the body's vascular system in different ways.

The Role of Vitamin C in Preventing Bruises

Vitamin C, or ascorbic acid, is vital for collagen synthesis, a structural protein that provides strength to blood vessel walls. Deficiency weakens capillaries, making them prone to rupture and bruising. Severe deficiency can lead to scurvy, characterized by easy bruising and other symptoms.

Symptoms of Vitamin C Deficiency

Easy bruising and petechiae (tiny red or purple spots)
Bleeding gums
Poor wound healing
Fatigue
Joint pain

The Connection Between Vitamin K and Blood Clotting

Vitamin K is essential for producing clotting factors in the liver, which are crucial for blood coagulation. Deficiency impairs this process, increasing the risk of bleeding and bruising. Risk factors include poor diet, malabsorption issues, and long-term antibiotic use.

Symptoms of Vitamin K Deficiency

Easy bruising or bleeding
Prolonged clotting time
Heavy menstrual periods
Blood in the urine or stool
Vitamin K Deficiency Bleeding (VKDB) in newborns

Comparing Vitamin C and Vitamin K Deficiencies


Feature	Vitamin C Deficiency	Vitamin K Deficiency
Primary Role	Collagen synthesis for strong blood vessels	Production of blood clotting proteins
Bruising Cause	Weakened blood vessel walls prone to rupture	Impaired blood clotting process
Other Symptoms	Bleeding gums, poor wound healing, fatigue	Excessive bleeding, prolonged clotting time
Key Food Sources	Citrus fruits, bell peppers, broccoli, berries	Green leafy vegetables, vegetable oils, some fermented foods
Who is at Risk?	Elderly, those with restrictive diets, malabsorption issues	Newborns, malabsorption issues, long-term antibiotic users

Other Causes of Easy Bruising

Beyond vitamin deficiencies, easy bruising can be caused by:

Aging: Thinner skin and less protective fat layer.
Medications: Blood thinners and certain pain relievers can increase bruising.
Bleeding Disorders: Genetic conditions affecting blood clotting.
Liver Disease: Reduced production of clotting proteins.
Cancers: Conditions like leukemia affecting platelet counts.
Alcohol Consumption: Impact on liver function and clotting.

How to Address a Vitamin Deficiency

Dietary changes are key. Increase intake of vitamin C-rich foods like citrus fruits and vitamin K-rich foods like leafy greens. Supplementation may be recommended by a healthcare provider. More information on vitamin K is available from the National Institutes of Health. [^1]

When to Consult a Healthcare Provider

Seek medical attention for:

Frequent, large, or unexplained bruising.
Bruising that worsens or spreads.
Numbness or loss of function in a bruised limb.
Signs of infection around a bruise.
Bruises with other symptoms like bleeding gums or excessive bleeding.

Conclusion

Deficiencies in Vitamin C and Vitamin K are significant causes of easy bruising. Vitamin C supports strong blood vessels through collagen, while Vitamin K is vital for blood clotting. A balanced diet is crucial for prevention. Consult a doctor for persistent, unexplained bruising to identify and address underlying issues.

[^1]: Vitamin K: Fact Sheet for Health Professionals

Frequently Asked Questions

Deficiencies in both vitamin C and vitamin K are primary causes of blood bruises. Vitamin C deficiency weakens blood vessels, while vitamin K deficiency prevents proper blood clotting.

Vitamin C is necessary for producing collagen, a protein that maintains the strength of blood vessel walls. When vitamin C levels are low, blood vessels become fragile and more susceptible to rupturing and bruising.

Vitamin K is essential for the liver to produce proteins called clotting factors. Without enough vitamin K, your blood's ability to clot is impaired, which can lead to excessive bleeding and easy bruising.

For most healthy adults, a balanced diet is sufficient. Foods rich in vitamin C include citrus fruits, bell peppers, and broccoli, while leafy greens like kale and spinach are excellent sources of vitamin K.

You should see a doctor if you experience frequent, large, or unexplained bruising, or if your bruising is accompanied by other symptoms like bleeding gums, joint pain, or excessive bleeding from minor cuts.

Other common causes include aging, certain medications (such as blood thinners), liver disease, bleeding disorders like hemophilia, and various cancers or other medical conditions.

Severe vitamin C deficiency (scurvy) is rare in developed countries but can still occur in individuals with poor dietary habits, malabsorption issues, or certain medical conditions.