Global Study Says When Vitamin D Is Low, Dengue Hits Harder: What It Could Mean For India
The fear of a dengue outbreak has intensified in recent weeks, especially as cases of chikungunya have surged in Tamil Nadu. Understnad the role of Vitamin D in fighting infections.
Dengue is a mosquito-borne illness that has become a major public health crisis across the country. Despite many efforts to eradicate dengue by the health authory there has been a significant increase in the number of dengue cases over the years. As per data released by the Ministry of Health and Family Welfare (MOHFW), India estimated 1,13,450 cases and 95 deaths in the country till November 2025.
Low Vitamin D Worsens Dengue Severity
The fear of a dengue outbreak has intensified in recent weeks, especially as cases of chikungunya have surged in Tamil Nadu. Adding to the concern, a study published by the Indian Journal of Medical Research (IJMR), a peer-reviewed journal of the Indian Council of Medical Research (ICMR), revealed that low vitamin D can increase the severity of this mosquito-borne illness.
The Colombian study examined blood samples of 98 dengue patients, which were classified as dengue without warning signs, dengue with warning sign or severe dengue. Researchers then took the serum samples and compared 10 healthy individuals. Scientists further found that people with no sign of dengue had higher vitamin D levels compared to individuals who had severe dengue. The result concluded that people who had lower vitamin D are at increase risk of inflammation and severe dengue, and people who had higher vitamin D showed a lower risk of the disease and inflammation.
"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.
In a similar study published by the International Journal of Toxicological and Pharmacological Research (IJTPR), scientists examined 156 dengue patients, where the findings revealed that serum vitamin D was found deficient in 66.7% of the total participants. Later, researchers from the Dr. Ram Manohar Lohia Institute of Medical Sciences (Dr. RMLIMS) concluded that the severity of dengue patients was directly related to low vitamin D.
Why Vitamin D Matters?
Vitamin D is a fat-soluble vitamin found in a variety of foods, added to others and available as a dietary supplement. Interestingly, your body can also make vitamin D naturally when the ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis. There are many reasons why vitamin D is essential for living a healthy lifestyle. These include:
- Vitamin D improves the immune system and helps resist bacteria and viruses,
- Vitamin D is essential for building muscle and nerve functions,
- Vitamin D is important for building strong bones by allowing the body to absorb calcium,
- Vitamin D helps reduce inflammation,
According to the Centres for Disease Control and Prevention (CDC), the risk of vitamin D deficiency for an individual increases when they have limited exposure to sunlight which can generate natural vitamin D. Other factors that decrease vitamin D deficiency in a person include:
- Leaving at high altitude,
- Hazardous level of air pollution,
- Dense cloud covering,
- The degree to which clothing covers the skin,
- Excessive use of sunscreen,
- Darker skin types,
The US health agency further notes that a person living with insufficient vitamin D may experience certain health problems, such as:
- Obesity,
- Cardiovascular disease (CVD),
- Diabetes,
- Elevated hypertension,
- Low High-Density Lipoprotein Cholesterol (HDL C),
- Adding bones or frequent fractures,
- Depression,
- Mood swing,
- Frequent infections like cold and flu,
Role Of Vitamin D In Fighting Infections
Vitamin D is well known for its role in supporting a healthy lifestyle, but multiple studies have shown that deficiency or insufficiency of vitamin D is often associated with a greater risk of infections, particularly in the respiratory tract. The National Institute of Health (NIH) notes that the exact mechanism by which vitamin D may improve your immune response to infection is yet to be evaluated. However, given its influence on the immune system and inflammatory cascade, this vitamin may have an important role in the prevention and treatment of infection.
"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. Although originally recognized as a key regulator of bone and mineral homeostasis, which it clearly is, the influence of vitamin D on the immune system illustrates its role beyond bone," the NIH explains. "That said the immune system also plays a role in the skeleton, such that although this review focuses on infection, especially by COVID-19, it is equally certain that vitamin D influences skeletal metabolism at least in part as an important constituent in osteoimmunology."
Vitamin D Deficiency Vs Dengue: What Could Mean For India
According to the World Health Organisation (WHO), dengue has emerged as a rapidly spreading vector-borne disease across the globe. The global health organisation notes that it affects over 30 countries in the world, including India. At the same time, studies on Vitamin D deficiency in the country revealed that the majority of the population is not receiving enough sunlight. Combining these facts, a significant public health concerns rasies as many people in India are vitamin D deficient, allowing them to be more vulnerable to severe dengue outcomes.
Dengue Symptoms To Watch Out For
Amid the chikungunya outbreak in Tamil Nadu, Dr. RR Dutta, HOD, Internal Medicine, Paras Health, explains that dengue and chikungunya outbreaks can occur at the same time because the same mosquito can transmit both viruses, i.e. Aedes aegypti and Aedes albopictus. He says that the viruses could adapt to the urban environment and continue in a "chain of transmission when one mosquito population sustains the spread if the viruses are in the community." Dengue is a viral infection that is spread from mosquitoes to people, particularly in tropical and subtropical regions. According to healthcare professionals, many people who get this viral infection do not have symptoms, but for those who do, the most common symptoms include the following:
- High fever,
- Severe headache,
- Rash,
- Swollen glands,
- Vomiting,
- Pain behind eyes,
- Muscle and joint pains,
- Nausea,
WHO notes that individuals who are infected for the second time are at a greater risk of severe dengue with symptoms that include:
- Persistent vomiting,
- Severe abdominal pain,
- Rapid breathing,
- Bleeding gums or nose,
- Fatigue,
- Blood in the vomit or stool,
- Feeling weak,
- Restlessness,
- Being very thirsty,
- Pale and cold skin,
Tips To Prevent Dengue
As of now, there is no specific treatment for dengue apart from managing the pain with certain medications like paracetamol. The global health organisation outlines that there are two vaccines available to treat dengue, but it is only recommended for children who are living in areas where the mosquito-borne illness is very common, including Puerto Rico. Keeping this in mind and the risk associated with severe dengue, there is no better way to protect yourself from mosquito bites than by following these life-saving tips:
- Make sure to cover yourself properly when you are going out,
- Use EPA-registered insect repellents containing DEET, Picaridin or IR3535,
- Do not forget to remove standing water, as it could be a breeding ground for mosquitoes,
- Prevent mosquitoes from entering your indoor space by using window screens and sealing holes,
- Always use a mosquito net while sleeping during the day and night,
- If you are pregnant, then avoid travelling to areas where mosquitoes or dengue cases are being reported,
- To be always on the safe side, check with the health authorities to understand if there are any outbreaks of illness in your destination before you leave,
The NIH outlines that the course of dengue progresses through three phases, i.e. febrile, critical and recovery. It advises, "In the absence of specific antiviral treatment, the 2009 WHO guidelines recommend supportive care, including adequate hydration, analgesia (avoiding nonsteroidal anti-inflammatory drugs [NSAIDs] such as ibuprofen and naproxen due to the heightened risk of bleeding), rest, and close monitoring for severe signs like hypotension and bleeding."
