The body’s defences; viruses

Illnesses are often caused by invisible particles — viruses and germs. Preventing them is easier than curing them. The body has its own defenders — leukocytes in the blood. When they meet a foreign bacterium or virus they attack and destroy it, and remember it, so next time they fight it faster. The body’s ability to resist disease is called immunity. A newborn first gets some protective substances from its mother’s milk. Immunity is helped by helpful gut bacteria, proper food, vitamins, sleep and activity. Vitamin A supports eyesight and skin, B supports the nervous system, C supports the body’s defences, and D strengthens bones. Long ago sailors on long voyages got scurvy from a lack of vitamin C; lemons, oranges, cabbage and peppers are rich in it. Do not take vitamins or medicines without an adult and a doctor’s advice.