New Delhi: A clinical study from Colombia, published in the Indian Journal of Medical Research, the peer-reviewed journal of the Indian Council of Medical Research (ICMR), has found that low vitamin D levels are linked to more severe dengue, a finding with clear relevance for India, where both dengue and vitamin D deficiency are widespread.
Dengue remains a recurring public health challenge in the country, especially during the monsoon, when hospitals see sharp rises in patients with high fever, falling platelet counts and bleeding complications. While many recover with supportive care, a significant proportion deteriorate rapidly, and predicting severity remains difficult.
In the Colombian study, researchers analysed blood samples from nearly 100 laboratory-confirmed dengue patients, classified by disease severity, and compared them with healthy individuals. They measured serum vitamin D levels along with miRNA-155, a molecule that regulates immune and inflammatory responses. Patients with milder dengue had higher vitamin D levels, while those with warning signs or severe disease showed significant deficiency.
At the same time, miRNA-155 levels rose steadily with increasing severity, indicating an exaggerated immune response. The study also found an inverse relationship between vitamin D and inflammatory markers such as TNF-alpha and interleukin-6, both linked to severe dengue and complications like dengue haemorrhagic fever.
Commenting on the findings, Dr R. Goswami, professor of endocrinology at the All India Institute of Medical Sciences, said the study strengthens earlier evidence linking low vitamin D with severe dengue, particularly dengue haemorrhagic fever. “What this study adds is a possible disease mechanism through microRNA-155, which is involved in immune dysregulation via Th1 and Th2 pathways,” he said, adding that it is prudent to maintain normal levels.
Doctors say the findings resonate with Indian clinical experience. Dr Pankaj Soni, principal director (internal medicine) at Fortis Escorts Heart Institute, said low vitamin D is associated with bleeding and complications and may worsen inflammation and viral replication, making it a modifiable risk factor but not a treatment. Dr Atul Gogia, head of infectious diseases at Sir Ganga Ram Hospital, said severe dengue is often driven by a cytokine storm, and correcting deficiency could help reduce complications, though larger, well-controlled trials are needed.
India continues to face a heavy dengue burden, with about 1.13 lakh cases and 95 deaths reported till November 2025, and much higher numbers recorded in peak years such as 2023. At the same time, national studies show vitamin D deficiency affects a large majority of Indians across age and income groups. Experts caution against self-medication but say the study highlights the need for India-specific research to examine whether correcting widespread deficiency could help identify high-risk patients early and reduce dengue-related complications.
