The Reference Nutrient Intake in Britain is 7 mg for women and 9.5 mg for men (in the USA the RDA is 8 mg and 11 mg respectively).
Zinc is an essential mineral involved in more enzyme reactions than any other mineral.
Zinc dissolves in water, so cooking in water will wash some of it away.
Where do you get zinc?
Most animal foods contain zinc, including shellfish, red meat, eggs, fish, poultry, milk, yoghurt and cheese. It is also in shiitake mushrooms, whole grains, nuts, ginger, mustard, chilli powder and black pepper.
It is necessary for a healthy immune system, wound healing, maintenance of the senses of taste and smell, for DNA synthesis and for the proper function of many hormones such as insulin, growth and sex hormones. Every cell needs zinc to allow it to multiply.
Too much zinc
Toxicity is rare, but in recent studies supplements of 100 mg of zinc a day and more have shown a link to prostate cancer in men. Normal doses are not nearly as high as this.
Too little zinc
Low zinc levels can result from a vegetarian diet, during calorie-controlled diets, if you drink too much and when you are older.
Symptoms include appetite loss, no sense of taste or smell, skin problems, slow wound healing, mouth or leg ulcers, diarrhoea, menstrual problems in women and low sperm count in men.
Zinc deficiency is probably widespread. Our diet has too much processed and refined foods, fat and sugar. Improving the diet will improve the zinc level.
Supplements should be as multi-mineral products, although short-term use in 'immune boosting' products for colds and flu are safe and effective.