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Vitamins & Minerals Explained

The term 'vitamin' is derived from 'vital amine'. They are a group of substances required in small amounts for growth and development but which cannot be manufactured by the body.

Without vitamins the human body would not survive. We all need vitamins in order to live a long and healthy life. Most of us get sufficient quantities of vitamins from our food, but it may be necessary for some people to take a vitamin supplement (eg pregnant women and the elderly).

How easy is it to get all the vitamins we need from our diet?

A varied diet is essential if we are to obtain the nutrients we need. However, this is not always easy: fruit and vegetables age (an apple in a bowl loses vitamins hour by hour) and deep frozen products may often contain more vitamins than vegetables stored for a long time at room temperature. Therefore, it is especially important to eat a wide variety of fresh foods.

Too little of just one vitamin may disturb the body's balance and cause health problems. But taking too many vitamins can also be dangerous. This is especially true of the fat-soluble vitamins A, D, E and K: it is harder to get rid of excess of these vitamins through urine - the most common way for us to eliminate body waste products.

Where do vitamin supplements come from?

Most vitamin supplements have been extracted from natural foods. For instance, vitamin A comes from fish-liver oil. Vitamin B comes from yeast or liver. Vitamin C is often extracted from small berries in roses, and vitamin E is extracted from soy beans or maize. Vitamins may also be synthetically manufactured, but synthetic vitamins are not always as effective as their naturally derived equivalent.

How should vitamins be stored?

It is important to keep vitamins in a dark, cool place, or they will 'go off', just like apples in a bowl. The best place to store vitamins is in the refrigerator - make sure there is a lid on the container. A few grains of rice in the container will prevent moisture getting into the tablets.

When should you take vitamin supplements?

The best time to take vitamins is during the day, after a meal. Never take vitamins on an empty stomach - they will quickly passed out in your urine. This is especially true for the B and C vitamins that dissolve in water. The fat-soluble vitamins A, D, E and K can be stored in the body for up to 24 hours and can sometimes be stored in the liver for even longer.

Are vitamins and minerals the same thing?

Vitamins and minerals are two completely different things: minerals help the vitamins work. The 10 most important minerals are: calcium, iodine, iron, magnesium, phosphorus, copper, manganese, chromium, selenium and zinc. There is a specific recommended daily allowance for each of these, as well as for each of the vitamins.



This mineral is essential for strong healthy bones and teeth and plays an active role in the body's immune system. A lack of calcium in the diet is a contributing factor to osteoporosis, a condition that causes brittle bones in adults. High levels of calcium are found in dairy products such as milk and yoghurt. On average 250ml or half a pint of cow's milk or 150g/5oz of yoghurt contains 300mg of calcium.

In addition, calcium is available in the following non-dairy food sources: almonds, brazil nuts, broccoli calcium enriched soya cheeses, calcium enriched soya milks, curly kale, dried apricot and figs, hazelnuts, mackerel, okra, oysters, pilchards, pulses, salmon, sardines, sesame seeds, spinach, tofu, watercress.

Some dairy products are high in fat so you should meet your body's calcium needs by eating a diet containing a balance of dairy and non-dairy foods.


Iron is needed by the body to produce healthy blood and muscles. It plays an essential role in the production of the body's white blood cells and in the activities of the immune system. An adult female needs 12-15mg of iron a day, a male around 8-15mg.

There are two types of iron in food:

  • 'haem iron' found in lean red meat and offal (essentially the iron from blood and muscle)
  • 'non-haem iron' derived from some plants, grains and nuts.

Vegetable sources of iron also contain salts (oxalates and phytates) that unfortunately impair the efficient absorption of the iron. This results in the need to eat a lot more to obtain the iron that your body requires.

Both oily fish and egg yolks are quite rich in iron, but they also contain substances that impair the body's ability to absorb the iron effectively.

The body can absorb 20 to 40 per cent of the iron found in meat, but only 5 to 20 per cent of the iron found in vegetable sources. Therefore a mixture of iron sources should be included in the diet. The absorption of iron by the body is also dependent upon the presence of vitamin C and folic acid, which improve its efficiency and are an integral part of the absorption process.

Cutting down on the intake of tannin and caffeine that are found in tea, coffee, chocolate and cola-based drinks helps iron absorption.

Sources of iron include: apricots, beans - (including baked beans), blackcurrants - canned, broccoli, curly kale, eggs, figs, kidney, lean red meat, lentils, liquorice, liver, mackerel, nuts, oysters, peas, prunes, poultry or game, raisins, sardines, savoy cabbage, spinach, tuna, watercress, wholegrain cereals, wholemeal bread.


Small but regular amounts of this nutrient are needed for the maintenance of a healthy liver and as one of the body's antioxidants. Selenium is found in the soil and hence the amount found in foods is dependent upon the farming methods used to produce them. Over-cultivation of the land results in a depletion of its selenium levels and hence a reduction in the selenium content of the crop.

However, a diet that includes a combination of the following foods will ensure an adequate intake of selenium: Brazil nuts, cashew nuts, cheese, chicken, eggs, garlic, green vegetables, lean meat, liver, mackerel, milk, onion, salmon, sunflower seeds, tuna, whole wheat bread.


Magnesium is involved in the regulation of the potassium and sodium levels within the body and hence the control of blood pressure. It is also important in the release of energy, building strong bones, teeth and muscles, and regulating body temperature. In addition, magnesium helps the body absorb and metabolise various other vitamins and minerals, eg calcium and vitamin C.

Including the following foods will ensure adequate intake: apricots, bananas, brown rice, courgettes, figs, granary bread, green leafy vegetables, lean meat, milk, nuts, okra, parsnips, peas, prunes, pulses, raisins, sweet corn, wholemeal bread, whole wheat pasta, yoghurt.


This mineral together with sodium is active in the regulation of the body's water balance mechanisms. Potassium is also important in the transmission of nerve impulses, heart rhythm and muscle function.

It is found in most foods except oils, fats and sugars, but can be lost if food is overcooked. Most fruit and vegetables contain potassium, with bananas, strawberries, fresh orange juice, apricots, prunes, potatoes and green leafed vegetables providing the best sources.

The recommended daily intake of potassium is 3500mg which is easily achieved with a mixture of the following foods: almonds, apricots - dried, apricots - fresh, artichoke, asparagus, bananas, barley, beetroot, blackcurrant, brown rice, brussels sprout, carrots, cauliflower, chicken, chick peas, corn, cranberries, cucumber, fennel, figs, garlic, ginger, grapefruit, kidney beans, kiwi fruit, leeks, lemons or limes, lettuce, melon, okra, onion, orange, parsnips, peaches, pear, peas, peppers, pineapple, potatoes, prunes, radishes, raspberries, spinach, strawberries, sweet potato, tofu, turnip.


Zinc is an antioxidant and important for the maintenance of a healthy immune system. Deficiency in zinc levels may be associated with skin problems, slow healing of wounds and low sexual libido.

The recommended daily allowance for zinc is 15mg, which is not difficult to achieve with a diet containing the following: brown rice, cheese, crab, duck, goose, kidney, lean red meat, lobster, mussels, oysters, sardines, turkey, venison, wholegrain breads.

Vitamins & Minerals - Putting Into Action

  • Include three to five servings of fruit and vegetables daily.
  • If possible eat vegetables raw and include them as part of a mid-morning snack or lunch.
  • When cooking vegetables, lightly steam them or use a salad as part of your main course.
  • Try to include oily fish two to three times a week.
  • Start the day with a wholegrain cereal; these are often fortified with vitamins and minerals. Try eating with enriched soya milk and substituting Marmite for marmalade.
  • Try to include fresh fruit juices at breakfast or as a mid-morning drink instead of tea or coffee.
  • If you need to have a snack, eat Brazil or cashew nuts or small quantities of dried fruit.
  • Take a boiled egg as part of your packed lunch. If possible, use wholegrain bread to make your sandwich, including salad as part of its filling.
  • Cut down on caffeine intake as this has an impact on the activity of vitamins and minerals.

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