Vitamins and Minerals
Small quantities of a range of vitamins and minerals are an essential part of our diet. Vitamins are complex molecules made by living things. Minerals are simple molecules also present in rocks and soil. Each of the different vitamins and minerals has a specific role to play in keeping us healthy.
Vitamins control the chemical reactions in our bodies, for example vitamin B1 controls some of the chemical reactions that release energy from nutrients in food.
Vitamins are only needed in tiny quantities and these are usually supplied by a balanced diet. Plants make many of the vitamins we need and we can produce a few for ourselves, for example, we make vitamin D from cholesterol.
If you don't get enough of any of the vitamins you will fall ill, for example, if you don't get enough vitamin A your eyesight will deteriorate.
Vitamin supplements will help if your diet is deficient in vitamins. However, just as vitamin deficiencies lead to poor health so too can excesses. In an extreme example, after taking 10 000 times the recommended daily dose of vitamin A for 10 days an English man turned bright yellow and died of liver damage.
Minerals. We need at least 20 different mineral elements including sodium and calcium for good health. All of these minerals are found in our food.
Sodium is one of the minerals that is essential for controlling the fluid balance in our bodies. Water is drawn in and out of our cells to balance the amount of sodium in our blood. Salt is nearly pure sodium and chlorine. Most people consume enough salt each day to provide more than 10 times the amount of sodium they need. Too much sodium can result in high blood pressure and put a strain on the heart.
Calcium hardens our bones and teeth. Our bodies contain nearly 100g of calcium and we need to replace the calcium we lose through excretion. We get calcium from milk and some green vegetables. If we don't get enough our bones become weak and fracture easily.
Iron is important in transporting oxygen around our bodies. Sources of iron include red meats, green vegetables and beans. Our bodies are not very efficient at absorbing iron. A shortage of iron leads to paleness and a feeling of fatigue.