Food, water and oxygen are the substances upon which life on this planet is based. Food provides us with both the energy and the nutrients required to build, maintain and repair all our body cells. The study of nutrition is the study of these foods and their nutrients, what they consist of, how the human body digests, absorbs and utilises them and what they do to support life and health.

Vitamins and minerals are essential for life and for optimal human physical and mental health and wellbeing. Deficiencies of these nutrients develop through various stages. With increasing deficiency, the symptoms become more noticeable and specific and therefore easier to define and classify.

Lifestyle and dietary choices influence requirements significantly. Those who drink alcohol, tea or coffee, smoke or take various drugs (prescription or otherwise) or who participate in high levels of exercise will have greater requirements of specific nutrients. For example, drinking alcohol requires larger amounts of B vitamins, zinc and magnesium for metabolism; because these are water-soluble nutrients they are also excreted more quickly with alcohol’s diuretic effect.

Many believe that eating a fresh, well-balanced diet provides all the vitamins and minerals necessary for good health. In ideal circumstances this is the case. However, there are many reasons vitamin and mineral supplements are necessary to cope with living in the twenty-first-century environment. In addition to the foodgrowing and processing issues mentioned above, the following is a selection of reasons as to why supplementation may be necessary.

Poor digestion

Poor digestion is a major issue as even if food intake is adequate, poor digestion can limit the body’s absorption of vitamins and minerals. Eating too quickly can result in larger than normal food particles (macromolecules) which are too large to allow for the complete action of digestive enzymes. Many people with dentures also are unable to chew efficiently. Consuming foods or drinks (or drugs such as aspirin) that can cause inflammation of the digestive lining can result in a lowering of digestive enzymes and decreased extraction of vitamins and minerals from food.

Alcohol consumption

Alcohol in excess is known to damage the liver and pancreas, which are vital to digestion and metabolism. Alcohol can also damage the lining of the intestinal tract, adversely affecting the absorption of nutrients and leading to subclinical malnutrition. Regular heavy use of alcohol increases the body’s needs for the B group vitamins, particularly B1 (thiamine), B3 (niacin), B6 (pyridoxine), folic acid and vitamin B12, and vitamin C. Alcohol also increases the need for the minerals zinc, magnesium and calcium and affects the availability, absorption, metabolism and excretion of all these nutrients.

Tobacco smoking

Smoking tobacco is an irritant to the mucous membranes of both the digestive tract and lungs, and increases metabolic requirements of vitamin C. Each cigarette uses up 25 mg of vitamin C and smokers need 30 per cent more than non-smokers. Smokers also have greater requirements for vitamin A, zinc and lecithin to repair lung membranes.

Laxatives

Laxatives (or chronic diarrhoea) can result in poor absorption of vitamins and minerals from food, by hastening the intestinal transit time. Paraffin and other mineral oils increase losses of the fat-soluble vitamins A, D, E and K and essential fatty acids. Other laxatives used in excess can cause losses of minerals/electrolytes such as potassium, sodium and magnesium.

Fad diets

Fad ‘diets’ that leave out whole groups of foods can be seriously lacking in vitamins and minerals. Even the popular low-fat diets, if used too often or for too long a time, can generate a significant deficiency of the fat-soluble vitamins A, D, E and K and essential fatty acids. Vegan (and many vegetarian) diets must be very well planned to avoid iron, vitamin B12 and zinc deficiencies.

Antibiotics

Antibiotics, although valuable in fighting severe infections, also kill off the friendly bacteria in the gut, adversely affecting digestion. It is always important to take a lengthy course of B group vitamins and acidophilus or bifidobacteria for up to six weeks after antibiotics. Hormone replacement and the pill also decrease absorption of folic acid and increase the need for the vitamin B group, vitamin C, magnesium and zinc.

Drugs use

Many people are on prescription drugs for a variety of conditions. While these may sometimes be lifesaving they can also increase the need for a variety of nutrients. For example, taking antacids will lower levels of calcium, iron, potassium, vitamin A and vitamin B1. Anti-inflammatory drugs increase the need for vitamins B6, C and E and iodine. Antihypertensive medication increases the need for vitamins B6 and B12, potassium and magnesium. Steroid medication increases the need for calcium, iron, zinc and vitamins B6, C and D. Even the humble aspirin increases the need for vitamin C.

Burn

Burns lead to a loss of protein and essential trace nutrients. Surgery increases the need for zinc, vitamin E and other nutrients involved in the cellular repair mechanism. Vitamin C is vital to detoxify anaesthetics and prevent surgical shock (adrenal exhaustion). The repair of broken bones will be slowed by a deficiency of calcium, boron and vitamin C. The challenge of infection places a high demand on resources of zinc, magnesium and vitamins B3, B6, A, C and E.

Stress

Chemical, physical and emotional stresses can increase the body’s requirements for vitamins B2, B3, B5, B6 and C. Air pollution increases the requirements for vitamins A and E and the mineral zinc.

Elderly

The elderly have been shown to have a consistently low intake of nutrients, particularly protein, calcium, zinc and magnesium. Folic acid deficiency and vitamin B12 deficiency are common. Fibre intake is often low. Riboflavin (B2) and pyridoxine (B6) deficiencies have also been observed. Possible causes are low sense of taste and smell (a sign of zinc deficiency), reduction of digestive enzyme secretion, chronic disease and regular prescription drug use.

Sunlight

Invalids, shift workers and those whose exposure to sunlight may be minimal can suffer from insufficient amounts of vitamin D, which is required for calcium metabolism, increasing the risk of osteoporosis.

Ultraviolet

Ultraviolet light is the stimulus for vitamin D production in the skin. Melatonin levels may also be lowered inducing insomnia and depression. This can be exacerbated by long hours on the computer or in a room with electromagnetic radiation (EMR).

Deficient trace elements in food sources

Many agricultural soils are deficient in trace elements. Decades of intensive monocultures can overwork and deplete soils unless all the soil nutrients are replaced. Unfortunately only the ones known to produce larger crops are usually added. From the Earth Summit Report in Rio in 1992, figures showed that in the United States levels of essential minerals in crops were found to have declined over a 100- year period by up to 85 per cent, and Australian soils had (on average) a 55 per cent mineral depletion in that same timeframe.