Which Vitamin Deficiency Can Cause Fever? An Expert Guide

October 29, 2025 •

4 min read

While it is not a common cause, research has confirmed that certain severe nutritional deficits can lead to fever, particularly in rare cases of megaloblastic anemia caused by a vitamin B12 deficiency. Understanding which vitamin deficiency can cause fever requires delving into the body's immune response and how specific vitamins support its function.

Quick Summary

This guide explains the connection between certain vitamin deficiencies, such as B12 and C, and the onset of fever. It details how severe nutritional gaps can impair immune function and lead to conditions like megaloblastic anemia or scurvy, which present with fever as a rare symptom.

Key Points

Vitamin B12 Deficiency: Severe B12 deficiency can cause fever, often linked to megaloblastic anemia, where intense bone marrow activity may release inflammatory signals.
Advanced Vitamin C Deficiency (Scurvy): Fever can be a symptom of advanced scurvy, resulting from a severely weakened immune system that makes the body susceptible to secondary infections.
Indirect Link via Weakened Immunity: Deficiencies in vitamins like A, C, and D compromise the immune system's function, increasing the risk of infections that trigger a fever response.
Fever Resolution: In cases where vitamin deficiency is the cause, fever typically resolves rapidly after appropriate vitamin repletion therapy begins.
Diagnostic Consideration: Though rare, nutritional deficiencies should be considered in the diagnosis of pyrexia of unknown origin, especially when paired with other signs of malnutrition.
Not a Direct Cause: Vitamin D deficiency itself does not directly cause fever but increases vulnerability to infections which can lead to fever.

Severe Vitamin B12 Deficiency and Megaloblastic Anemia

Severe vitamin B12 deficiency is one of the most documented nutritional causes of pyrexia (fever). The mechanism is not fully understood, but it is believed to be linked to the profound changes that occur within the bone marrow during megaloblastic anemia, a condition where red blood cells are abnormally large and immature. This rapid turnover of bone marrow cells is thought to release inflammatory cytokines into the bloodstream, triggering a fever. In many case studies, the fever, which can sometimes be quite high, resolves rapidly once parenteral vitamin B12 therapy is initiated, reinforcing the link. This form of fever, often labeled as a Pyrexia of Unknown Origin (PUO), is a rare but treatable manifestation that should not be overlooked by healthcare professionals.

Other Symptoms of B12 Deficiency

In addition to fever, a severe B12 deficiency can manifest with a variety of other symptoms, some of which are neurological and others hematological. Patients may experience fatigue, weakness, shortness of breath, a sore tongue, and neurological issues like numbness or tingling.

Advanced Vitamin C Deficiency (Scurvy)

While notoriously associated with fatigue and bleeding gums, the advanced stages of vitamin C deficiency, known as scurvy, can also cause fever. Scurvy can severely compromise the body's immune function, making it vulnerable to secondary infections that trigger a fever response. In very rare and severe cases, untreated scurvy can lead to more serious complications, including infections that elevate body temperature significantly.

The Immune Role of Vitamin C

Vitamin C is a powerful antioxidant crucial for immune system function, particularly in supporting white blood cell production and activity. A severe lack of this vitamin impairs the body's ability to fight off pathogens effectively. Therefore, any febrile episode in a person with advanced scurvy is likely a result of an opportunistic infection taking hold due to a compromised immune system.

The Role of Vitamin D in Immune Modulation

Vitamin D deficiency is linked to a weakened immune system and a higher susceptibility to infections, though it is not a direct cause of fever. Low vitamin D levels have been associated with an increased risk of respiratory tract infections and other illnesses, which can naturally lead to fever. While correcting a vitamin D deficiency is important for overall immune health and can reduce the incidence of infections, the deficiency itself does not typically cause a fever. Its role is more indirect, influencing the body's susceptibility rather than being the primary fever-inducing agent.

How Vitamin Deficiencies Compromise Immune Function

An inadequate intake of key vitamins weakens the body's immune response, paving the way for infections that cause fever.

Effects on immune cells: Deficiencies in vitamins like B12, C, D, and others can negatively affect the function and number of immune cells, including T-lymphocytes, B-cells, and neutrophils. Impaired physical barriers: For instance, a deficiency in Vitamin A can compromise the integrity of the epithelial tissue in the respiratory and intestinal tracts, which are the body's first line of defense against pathogens. Inadequate cytokine response: The production of cytokines, which are crucial for immune communication, can be impaired by deficiencies, leading to a less effective immune response.

Comparison of Vitamin Deficiencies and Associated Fever


Feature	Severe Vitamin B12 Deficiency	Advanced Vitamin C Deficiency (Scurvy)	Severe Vitamin D Deficiency
Direct Cause of Fever	Yes, though rare. Mechanism potentially linked to bone marrow activity (megaloblastic anemia).	Yes, though rare and typically due to secondary infections.	No, not a direct cause. Linked to increased susceptibility to infections.
Immune System Impact	Impairs immune cell function, particularly phagocytic capacity of neutrophils.	Significantly compromises general immune response; crucial for white blood cell function.	Modulates adaptive and innate immunity; lower levels associated with higher infection risk.
Fever Resolution	Rapid resolution with parenteral vitamin B12 treatment.	Resolution with repletion of vitamin C and treatment of any secondary infection.	No specific resolution of fever, but supplementation boosts overall immune health.
Associated Symptoms	Fatigue, weakness, neurological issues, sore tongue, shortness of breath.	Malaise, lethargy, bleeding gums, easy bruising, poor wound healing, joint pain.	Fatigue, bone pain, muscle weakness, mood changes.

Conclusion

While a direct causal link between vitamin deficiency and fever is rare, it is an important consideration in specific, severe cases. Severe vitamin B12 deficiency, typically through its role in megaloblastic anemia, and advanced vitamin C deficiency (scurvy), can both manifest with fever as a symptom. These instances are not common and are usually accompanied by other more characteristic signs of deficiency. For less severe deficiencies, such as vitamin D, the link to fever is indirect; it stems from a weakened immune system that becomes more prone to infections, which then cause the febrile response. It is crucial to remember that a fever is a symptom, not a diagnosis, and should always prompt a thorough medical evaluation to determine the underlying cause. Nutritional deficiencies, though rare causes, should be part of the differential diagnosis in cases of unexplained fever, especially if other signs of malnutrition are present. Correcting the deficiency, as demonstrated with B12 and C repletion, is often key to resolving the fever and other symptoms.

Understanding a nutritional deficiency and its impact on the immune system is vital for maintaining overall health. The National Institutes of Health provides extensive information on various nutrients and their functions.

Frequently Asked Questions

Low vitamin D does not directly cause a fever. However, a deficiency in vitamin D can weaken the immune system, making a person more susceptible to infections that can then cause a fever.

No, fever is a very rare symptom of vitamin deficiency and typically only occurs in severe, untreated cases, such as with megaloblastic anemia due to a vitamin B12 deficiency or advanced scurvy (vitamin C deficiency).

In cases of severe B12 deficiency leading to megaloblastic anemia, the bone marrow's intense, ineffective blood cell production may release inflammatory substances. This heightened internal activity is believed to cause the body's temperature to rise, resulting in a fever.

Megaloblastic anemia is a blood disorder often caused by vitamin B12 or folate deficiency, characterized by large, immature red blood cells. In severe instances, the abnormal bone marrow activity associated with this condition can cause an inflammatory reaction, leading to fever.

Beyond fever, symptoms can include fatigue, weakness, a sore and red tongue, shortness of breath, and neurological issues like numbness or tingling in the hands and feet.

Yes, in the advanced stage known as scurvy, a severe vitamin C deficiency can cause fever. This is usually an indirect result of the immune system being so weakened that it cannot fight off opportunistic infections.

Fever caused by a nutritional deficiency is treated by addressing the underlying cause. For example, a fever from severe B12 deficiency typically resolves rapidly after treatment with vitamin B12 injections begins. For scurvy, replenishing vitamin C levels and treating any co-existing infections is necessary.