**2.1 Diet and nutrition**

Good nutrition is elemental to improving immunity and with ageing it is pivotal to supplement individual's diet with appropriate magnitude of nutrition. The first line of defence is to choose healthy diet packed with various micronutrients that supports optimal function of the immune system. Based on variety of systematic and evidence-based data, Vitamins: A, C, D, and minerals: Zinc and iron are particularly crucial to boosting immune response [5, 6]. Their details with main contribution, food sources and daily requirement is shown in **Box 1**.

