Although fish contain less iron than the amount found in red meat, iron in white fish is well absorbed and so is a useful source of iron. However, on a weight for weight basis, shellfish contain as much iron as lean meat. Iron is important in the body to prevent anaemia. Women with heavy periods and those that avoid red meat can sometimes go short of iron, especially if they don’t look out in particular for iron rich foods in their diet. Iron is essential for carrying oxygen around the body and a shortage of it will make you feel very weak and tired.

Small fish, like sardines, which contains small bones that can be eaten, are a very rich source of calcium. Calcium is important for bone health and teenagers and young people who have not reached their peak bone mass sometimes go short of this mineral.

Fish is a particularly good source of the mineral selenium. Selenium is a component of some of the enzymes which reduce the risk of free radical damage. It is also necessary for the use of iodine in thyroid hormone production and for immune system function. Intakes of selenium fall far short of the recommended intake. A typical portion of cod would give you over half of your daily recommended intake.

Fish is one of the few reliable sources of the mineral iodine and can provide a significant proportion of our recommended daily intake. Meat contains very little iodine. Iodine is used to make thyroid hormones, which control many of the body’s processes. If there is insufficient iodine in the diet, we can feel lethargic. Iodine is also required for normal neurological development and for energy metabolism.

High-protein foods contain the highest amount of zinc, i.e. meat and fish, and it is easily absorbed from these sources. Oysters provides more zinc than any other food and other types of fish and seafood provides a significant amount too such as skate, anchovies, herring, sardines, crab, prawns, shrimps,mussels, and winkles.

Zinc is needed for the body's defense (immune) system to properly work. It plays a role in cell division, cell growth, wound healing, and the break down of carbohydrates. Zinc is also needed for the senses of smell and taste.

Fish is a great source of vitamins A, D, E and the B vitamins. Oily fish is a better source of the fat soluble vitamins: A, D and E , than white fish or red meat. Indeed oily fish is the best natural dietary source of vitamin D. Vitamin D is not found in many foods and tends to be a vitamin that many vulnerable groups go short of, such as teenage girls and the elderly. Although vitamin D can be made in the body by the action of sufficient sunlight on the skin, many still do not get enough of this vitamin in the UK. Alongside calcium, vitamin D is essential for bone health, but it also plays a role in immune function.

Fish is also a good source of the B vitamins and can provide a useful contribution to the diet for this group of vitamins. The B group of vitamins is responsible for converting food to energy in the cells of your body and they help with the function of nerve tissue.