- Low Vitamin D Worsens Dengue
- Immune Over Reaction Drives Severity
- A Special Interview with Prof Kiran Madala
Article Today, Hyderabad:
Dengue, a mosquito-borne viral infection, does not affect all patients in the same manner. While some recover with mild fever, others slip into life-threatening complications. Recent scientific evidence has thrown light on a crucial factor behind this difference — Vitamin D deficiency. In an exclusive interaction, Dr Kiran Madala, Professor at Gandhi Medical College, explains the findings of an ICMR-backed study and the biological mechanisms that link Vitamin D to dengue severity.
Article Today: Dengue does not appear severe in everyone. Why is that so?
Dr Kiran Madala: Dengue severity depends largely on how the immune system responds after the virus enters the body. In some patients, the immune response remains balanced. However, in others, excessive production of pro-inflammatory cytokines occurs. This immune overreaction leads to severe inflammation and worsens the disease.
Article Today: What role does Vitamin D play in reducing dengue severity?
Dr Kiran Madala: Vitamin D acts as a natural antiviral agent. It limits viral replication and helps regulate immune responses. Importantly, it controls inflammation triggered by monocytes and macrophages. By doing so, it protects blood vessels from damage and prevents complications.
Article Today: What are the key findings of the ICMR study?
Dr Kiran Madala: The study examined 98 dengue patients. It found that those with lower Vitamin D levels suffered from more severe disease. Patients with critical symptoms consistently showed very low Vitamin D levels compared to those with mild dengue.
Article Today: What exactly is microRNA-155?
Dr Kiran Madala: MicroRNA-155 is a small non-coding molecule that regulates gene expression. It plays a major role in immune regulation. During viral infections, it promotes inflammatory signaling, which increases immune-driven damage.
Article Today: Is there a link between Vitamin D and microRNA-155?
Dr Kiran Madala: Yes. The study confirms an inverse relationship. Adequate Vitamin D suppresses the expression of microRNA-155. As a result, harmful cytokine production reduces. This prevents dengue from progressing into a severe stage.
Article Today: How low were Vitamin D levels in severe dengue patients?
Dr Kiran Madala: In patients with severe dengue, average Vitamin D levels were around 20 nanograms per millilitre. In contrast, patients with uncomplicated dengue had levels close to 33 nanograms. This clear difference highlights the role of deficiency.
Article Today: What are normal Vitamin D levels in healthy individuals?
Dr Kiran Madala: Healthy individuals without infections generally show Vitamin D levels around 44 nanograms. Compared to dengue patients, their immune systems function more efficiently due to adequate Vitamin D availability.
Article Today: What happens inside the body during severe dengue?
Dr Kiran Madala: Severe dengue weakens blood vessel walls. Plasma leakage occurs, leading to low blood pressure and reduced blood supply to vital organs. In addition, patients may experience bleeding, loss of consciousness, and life-threatening shock.
Article Today: What is meant by a cytokine storm?
Dr Kiran Madala: A cytokine storm refers to the excessive release of chemicals such as TNF-alpha, IL-6, and IFN-gamma. Instead of protecting the body, they damage tissues and increase blood vessel permeability. This leads to endothelial dysfunction in dengue patients.
Article Today: How does Vitamin D control this cytokine storm?
Dr Kiran Madala: Vitamin D regulates inflammation-related genes through cellular receptors. It suppresses signalling pathways such as NF-kB. Consequently, the release of harmful cytokines reduces significantly, keeping inflammation under control.
Article Today: Does Vitamin D supplementation help dengue patients?
Dr Kiran Madala: Earlier studies suggest that Vitamin D supplementation reduces dengue viral replication. High doses appear to protect macrophages from infection. However, further clinical trials are required before formal treatment guidelines can be issued.
Article Today: How is dengue diagnosed?
Dr Kiran Madala: Dengue is diagnosed using NS1 antigen tests and IgM and IgG antibody tests. These help detect both the virus and immune response. Early testing during the initial days of fever improves treatment outcomes.
Article Today: What advice would you give to the general public?
Dr Kiran Madala: People at risk of dengue should check their Vitamin D levels in advance. Adequate Vitamin D strengthens immune defence and helps prevent dengue from turning severe. Early awareness can save lives.
