Plants are the main source of nickel. Plants growing in soil contaminated with nickel can contain large amounts of nickel.
The richest nickel foods are nuts, peas, beans, chocolate, soy, lentils, oats, buckwheat, barley, corn. Fruits that contain nickel are in bananas and pears. Food of animal origin is a poor with nickel, but nickel can be also found in drinking water.
In addition to nickel in food, non-food souces of nickel are coins, jewelry, glasses frame, various household appliances, etc. A certain amount of nickel enters the body through the skin.