title: Serum electrolytes and skeletal mineralization in hard- and soft-water areas.
abstract: Serum levels of calcium and magnesium were measured in two Ontario cities that differ widely in the hardness of their local water-supply. The hypothesis being tested was that residents of the city with the hard water-supply (and a low cardiovascular death-rate) would show relatively high serum levels of calcium and/or magnesium. In addition, a comparison was made of the cortical thickness of the second metacarpal bone in the two areas to see if there was any evidence of increased skeletal mineralization in the hard-water area. The results obtained did not support either of these hypotheses, but it is suggested that the failure to demonstrate differences in body-levels of calcium or magnesium may not be incompatible with one (or both) of these water-borne elements functioning as the "water-factor" in cardiovascular disease.
mesh_terms: D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000097:blood* / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood* / Q000378:metabolism; D008297:Male; D008663:Metacarpus / Q000378:metabolism; D008875:Middle Aged; D009864:Ontario; D012737:Sex Factors; D014881:Water Supply / Q000032:analysis*
chemical_list: D008274:Magnesium; D002118:Calcium