Calcium, magnesium and copper are acknowledged nutrients in the human body, whereas strontium, which acts in a similar way to calcium, is presently suspected of playing a part in mineralisation in bone and teeth. The four elements are not shown to be carcinogenic in animals or humans but evidence for carcinogenicity of certain compounds such as calcium arsenate, magnesium silicate in talc and copper in intrauterine contraceptive devices is discussed. Experimental models in animals and in vitro studies have not provided evidence for the carcinogenicity or mutagenicity of these metals.