The fear of a dengue outbreak has intensified in recent weeks, particularly as cases of chikungunya surge in Tamil Nadu. A recent study highlights the critical role of Vitamin D in mitigating the severity of dengue, a mosquito-borne illness that has become a major public health crisis across India. Despite ongoing efforts to combat dengue, the Ministry of Health and Family Welfare (MOHFW) reported an estimated 113,450 cases and 95 deaths in the country as of November 2025.
A study published by the Indian Journal of Medical Research (IJMR) has revealed that low levels of Vitamin D can exacerbate the severity of dengue. This finding adds a new dimension to the public health challenge posed by the disease.
Low Vitamin D Worsens Dengue Severity
The study, conducted in Colombia, examined blood samples from 98 dengue patients, categorizing them based on severity. Researchers compared these samples to those from 10 healthy individuals and found that patients with severe dengue had significantly lower Vitamin D levels. The study concluded that individuals with lower Vitamin D are at increased risk of inflammation and severe dengue, whereas higher Vitamin D levels were associated with a reduced risk of the disease.
“These findings suggest a relationship between Vitamin D status, miRNA-155 expression, and immune activation during dengue infection. The inverse correlation between 25(OH)D and miRNA-155 highlights their potential as disease severity and progression biomarkers in patients infected by the dengue virus,” the study states.
Supporting these findings, a study published by the International Journal of Toxicological and Pharmacological Research (IJTPR) examined 156 dengue patients and found that 66.7% had deficient serum Vitamin D levels. Researchers from the Dr. Ram Manohar Lohia Institute of Medical Sciences (Dr. RMLIMS) concluded that the severity of dengue was directly related to low Vitamin D levels.
Why Vitamin D Matters
Vitamin D is a fat-soluble vitamin essential for various bodily functions. It can be obtained from certain foods, dietary supplements, and synthesized naturally when ultraviolet (UV) rays from sunlight trigger Vitamin D synthesis in the skin. The importance of Vitamin D extends beyond bone health, playing a crucial role in immune system function and inflammation reduction.
- Improves the immune system and helps resist bacteria and viruses
- Essential for muscle and nerve functions
- Important for building strong bones by aiding calcium absorption
- Helps reduce inflammation
According to the Centers for Disease Control and Prevention (CDC), the risk of Vitamin D deficiency increases with limited sunlight exposure. Other contributing factors include high altitude living, air pollution, dense cloud cover, excessive sunscreen use, and darker skin types. Deficiency can lead to health issues such as obesity, cardiovascular disease, diabetes, and frequent infections.
Role of Vitamin D in Fighting Infections
Vitamin D’s influence on the immune system is well-documented, with multiple studies linking its deficiency to an increased risk of infections, particularly in the respiratory tract. The National Institutes of Health (NIH) acknowledges that while the exact mechanisms are still being studied, Vitamin D’s impact on immune response and inflammation is significant.
“The impact that Vitamin D has on the immune system is a prime example of the broad spectrum of actions that Vitamin D has on physiologic and pathologic processes,” the NIH explains.
Vitamin D Deficiency vs. Dengue: Implications for India
According to the World Health Organization (WHO), dengue is a rapidly spreading vector-borne disease affecting over 30 countries, including India. Studies indicate that many Indians are Vitamin D deficient due to insufficient sunlight exposure, raising public health concerns about vulnerability to severe dengue outcomes.
Dengue Symptoms to Watch Out For
Amid the chikungunya outbreak in Tamil Nadu, Dr. RR Dutta, Head of Internal Medicine at Paras Health, explains that dengue and chikungunya outbreaks can occur simultaneously as the same mosquito species transmits both viruses. Dengue symptoms can vary, with some individuals experiencing no symptoms, while others may face:
- High fever
- Severe headache
- Rash
- Swollen glands
- Vomiting
- Pain behind the eyes
- Muscle and joint pains
- Nausea
WHO notes that those infected a second time are at greater risk of severe dengue, characterized by symptoms like persistent vomiting, severe abdominal pain, and bleeding.
Tips to Prevent Dengue
Currently, there is no specific treatment for dengue, apart from managing pain with medications like paracetamol. WHO outlines preventive measures, including:
- Covering up when outdoors
- Using EPA-registered insect repellents
- Removing standing water to prevent mosquito breeding
- Using window screens and mosquito nets
- Avoiding travel to areas with reported outbreaks
The NIH advises supportive care, including hydration and rest, while avoiding NSAIDs due to bleeding risks. As India grapples with dengue, addressing Vitamin D deficiency could be a vital step in reducing the disease’s impact.