Nutrienta - Advanced Nutritional Supplements. A healthy, effective immune system has never been more important to help us to avoid and reduce the symptoms of colds and flu… and not just in winter months. Supporting our immune system is important all year round, because everyday factors such as stress, a poor diet, insufficient exercise or a lack of sleep can also compromise our natural immunity. Nutrienta Immune Defence has been expertly formulated to help maintain a healthy immune system, with Vitamin C, Vitamin D, Selenium and Zinc, which contribute to the normal function of the immune system.