Tropical fruits and nuts. A selection of tropical fruits and nuts rich in vitamins and minerals. Fruits such as pineapple, melon, citrus fruits, bananas, plums, dates and mangos are seen. Nuts seen include Brazil nuts and almonds. Vitamins and minerals are an essential part of a nutritional diet. Minerals are particularly important in the functioning of enzymes, substances that promote biochemical reactions in the body. Vitamins regulate metabolism in the body. The fruits seen here are a source of vitamin C and biotin, a vitamin of the B complex. Nuts are a good source of minerals such as iron, zinc, magnesium and potassium.