A survey was conducted on age‐related changes in various measures of calcium metabolism in 609 men and women over the age of 30 (more than half were over the age of 60) in two communities of the Kii Peninsula at the central southern tip of the Japanese mainland. One community was on Oshima Island, with adequate nutritional intake; the other community was in the mountainous Shichikawa district, with a low intake of calcium and protein. The subjects of the Shichikawa study showed shorter stature, higher prevalence of lumbago, thinner clavicular cortex, lower serum levels of phosphorus, total protein and cholesterol, and a higher level of alkaline phosphatase than did the subjects of the Oshima study. There was no difference in the serum calcium levels.