Low Vitamin D May Worsen Dengue Outcomes, Global Study Raises Concerns for India

There is a very strong link between low vitamin D levels and severe dengue outcomes, a new study has revealed. The research, published in the Indian Journal of Medical Research, carries significant implications

for India, considering the high prevalence of both dengue fever and vitamin D deficiency across all age groups and genders.Scientists suggest clinicians must recognize that poor Vitamin D Dengue Severity outcomes are correlated with micronutrient status. The research from Colombia supports earlier evidence, but moreover, it sheds light on a possible mechanistic pathway Dengue is one of the major public health challenges in India, especially during the monsoon season, when hospitals across the country see sharp rises in cases of high fever, falling platelet counts, and complications related to bleeding. Even though most people recover with supportive care, a significant proportion deteriorate rapidly, and predicting severity remains difficult.

How was the study conducted?

For the study, researchers from Colombia analysed blood samples from nearly 100 laboratory-confirmed dengue patients, classified by disease severity, and compared them with those of healthy individuals. Serum vitamin D levels, along with miRNA-155 - a molecule that regulates immune and inflammatory responses, were measured, and it was found that those with milder dengue had higher vitamin D levels, while those with warning signs or severe disease showed significant deficiency. Also, the miRNA-155 levels rose steadily with increasing severity, which indicated an exaggerated immune response. The study also found an inverse relationship between vitamin D and other inflammatory markers, which are closely linked to severe dengue and complications like dengue haemorrhagic fever – a life-threatening complication. “What this study adds is a possible disease mechanism through microRNA-155, which is involved in immune dysregulation via Th1 and Th2 pathways,” Dr. R. Goswami, professor of endocrinology at the All India Institute of Medical Sciences, told the Economic Times. There are other reports too that have found that 66.7 per cent of dengue patients were vitamin D-deficient. Another report from Eastern India showed that vitamin D sufficiency offers a protective effect against disease progression in pediatric cases. Consequently, deficiency acts as a significant modifiable risk factor in a country facing an enormous dengue burden.

Dengue is a big problem for India

India continues to grapple with a significant dengue burden, with nearly 1.13 lakh cases and 95 deaths reported up to November 2025, and far higher case numbers seen during peak outbreak years such as 2023. At the same time, national surveys indicate that vitamin D deficiency is widespread in India, cutting across age groups and socio-economic backgrounds. While experts strongly caution against self-medication or unsupervised supplementation, they say the findings highlight the need for India-specific research to determine whether addressing this widespread deficiency could help identify patients at higher risk earlier and potentially reduce the severity of dengue-related complications.Also read: How to Maintain Healthy Vitamin D Levels During Short Winter Days

What is dengue?

Dengue is a viral infection transmitted by Aedes mosquitoes, causing high fever, severe headache, joint/muscle pain, and rash, with symptoms lasting 2 to 7 days. Common in tropical regions, it is caused by four dengue virus serotypes. While most cases are mild, severe dengue can be fatal. Prevention relies on avoiding mosquito bites, as no specific treatment exists.