Our bodies need a certain amount of the mineral zinc (usually 10-15 mgs daily) for healthy bone growth, reproduction, healing of wounds and the health of the skin and nervous tissues. It is associated with the good functioning of the senses of taste and smell - so vital in aromatherapy. Zinc deficiency can lead to partial or complete loss of the sense of smell, which will return with adequate supplementation if this is the cause.

Many environmental and other factors in modern life destroy zinc, or impair our ability to utilise it in the body. These include car exhaust fumes, food refining, the contraceptive pill and other drugs, so many people have far less than the optimum level of zinc in their bodies. Good food sources are fish and shellfish, eggs, wholegrains, peas and yeast, but supplementation is probably necessary if there are symptoms of deficiency, such as loss of the sense of smell or taste, brittle nails or white spots or lines under the nails.

People with certain skin diseases often respond well to an increase in the amount of zinc in their diet. Psoriasis, which is a notoriously difficult condition to treat, is often helped by upwards of 15 mg of zinc a day, so you should bear this in mind when treating a psoriasis sufferer with aromatherapy.