Dietary data for this study were pr

Dietary data for this study were provided by a nursing home in Niigata, Japan. Diet records, written by the nursing home’s dietitian, for 122 consecutive days between September and December 1999, were used. The amount of food for an individual was weighed before cooking and recorded on the diet record. Vitamin D–containing foods, including fish, eggs, meat, and mushrooms, were selected from the diet records, and their vitamin D (vitamin D2 plus D3) per day was calculated by referring to the Standard Tables of Food Composition in Japan.