The purpose of this study was to investigate the possible contribution of d
ifferent dietary nutrients in the development of esophageal cancer (EC) in
the Caspian littoral of Iran. Forty-one cases and 145 members of their hous
eholds were matched for age and gender with 40 non-blood-relative controls
and 130 members of their households for their nutrient intake. A standard 2
4-hour dietary recall questionnaire was used to estimate the daily intake o
f energy, protein, P, Fe, Na, K, vitamins C and A, thiamin, riboflavin, and
niacin. Dietary nutrient deficiency was defined as less than 75% of the Wo
rld Health Organization human nutritional requirements, except for P, Na, a
nd K, for which the United States Recommended Dietary Allowances were follo
wed. The results indicate the following: (1) The mean daily intake of all n
utrients, except for riboflavin, was significantly lower in cases than in c
ontrol subjects (P < .05); (2) with the exception of protein, riboflavin, a
nd phosphorus, significant correlation was observed between the pattern of
nutrient intake and health status of the study subjects (P < .05); and (3)
dietary deficiency of niacin and phosphorus was associated significantly wi
th the risk of EC development among case and control households (P < .01-.0
01), indicating that persons living in case households with dietary deficie
ncies of these nutrients have more than twice the risk of developing EC tum
ors than those living in control households. In conclusion, apparently some
nutrients, such as P and niacin, may play a role in the etiology of esopha
geal cancer, and the status of these nutrients may be used eventually as an
epidemiologic predictive marker for EC in the Caspian littoral of Iran and
perhaps other regions.