Nutrient deficiencies are surprisingly common. There are several reasons for this.

Intensive farming depletes the soil of nutrients, particularly minerals such as selenium, copper and zinc. Fruits and vegetables derive their nutrients from the soil and their nutrient content suffers as a result.

Modern food processing removes vital nutrients. White flour, for example, has lost 60% of its calcium, 85% of magnesium, 77% of zinc and 98% of its chromium. Modern diets that rely on highly refined convenience foods, and lack fruits and vegetables, simply cannot provide enough nutrients to support optimum health.

Most diets are high in sugar , whether directly from sweets, chocolate or cakes, or indirectly from sugar-enriched breakfast cereals and packet foods. Many so-called 'healthy' fruit bars are loaded with sugar. But, sugar has to be metabolised in the body along with all other foods and it takes nutrients to do that. Sugar does not provide any nutrients - it just eats them up as it passes through the body leaving a shortage of nutrients for other vital processes. The immune system is particularly susceptible and can be the first to suffer.

Many substances are ' anti-nutrients ' i.e. they take nutrients out of the body or cause an imbalance. Sugar can be placed in this category along with excess alcohol, cigarette smoke and heavy metals e.g. lead from pollution. Stress might also feature here because it depletes nutrients.