Dietary vitamin intake and cancer

We collected information on dietary intake from 9230 participants aged 40 years old or more by means of self-administered food frequency questionnaire in Fujieda city in order to conduct prospective study to examine the relationship between dietary VA, C and carotene intakes and subsequent risk of cancer in August 1985. To estimate VA, C, and carotene intakes from this questionnaire we multiplied food frequency scores for individual items (25 foods rich in VA, C, and carotene) by the nutrient contents of the standard portion, after adjustments were made for the seasonal availability of some foods.