The present invention provides methods for preparation of metallic amino acid chelates that are electrically neutral and free of interfering ions, by reacting a metal carbonate and an acidic amino acid in an aqueous solution, and the uses of said metallic amino acid chelates. The metallic amino acid chelates can be added to a product such as medical supplies, foods, beverages, cosmetics, feeds, etc., with maintaining the stability of the product at a variety of temperature and pH ranges and also having no effect on the properties of the product, including taste and appearance.