Boost your immune system: Evidence-based strategies for your defences

Dr. Charalampos Romanos · April 14, 2026 · 5 min read

The immune system is our defence against infection and disease. In my practice, I experience daily that a well-functioning immune system is the key to long-term health. The good news: the immune system can be deliberately strengthened — with evidence-based measures.

The role of vitamin D

Vitamin D is not just important for bones — it is an immune modulator. Low vitamin D status is associated with more frequent infections. I measure vitamin D levels (25-OH vitamin D) and optimise them to 60-80 ng/ml for optimal immune function.

Zinc: The underestimated mineral

Zinc is essential for T cell and natural killer cell function. Zinc deficiency leads to increased susceptibility to infection. In my health check-up, I test zinc status and recommend targeted optimisation.

Sleep is immune training

During sleep, immune cells are trained and multiplied. Too little or poor sleep weakens the immune system systematically. 7-9 hours of high-quality sleep is not a luxury — it is prevention.

Exercise and stress relief

Regular moderate exercise strengthens the immune system, while chronic stress weakens it. I recommend 150 minutes of moderate endurance exercise per week plus strength training to my patients, combined with stress-relief techniques.

Diet for immune health

An anti-inflammatory diet with sufficient antioxidants strengthens immune response. High-quality proteins, vegetables, fruits, nuts, and fish are central. This is part of my approach in preventive medicine.

Nutrient optimisation and supplementation

In addition to vitamin D and zinc, vitamin C, selenium, vitamin A, and probiotics are important. I develop customised nutrient profiles for each patient to optimally support their immune system.