Dietary vitamin A and the risk of invasive cervical cancer.

The relation between dietary vitamin A and the risk of invasive cervical cancer was evaluated using data from a hospital-based case-control study of 191 women with cervical cancer and 191 age-matched controls. There was no association between dietary retinoids and cervical cancer risk. Intake of dietary beta-carotene, on the other hand, was inversely and strongly related to the risk of cervical cancer. Compared to risks for women reporting a monthly intake of 150,000 or more international units (IU) of beta-carotene, the estimated relative risks for those with 100,000 to 149,000 and those with less than 100,000 IU per month were 2.8 and 6.1 respectively. The inverse association was not explained by any of the major identified risk factors for cervical cancer (including indicators of socio-economic status or sexual habits), or by differences in general characteristics and other lifestyle habits between cases and controls. Thus, although the uncertainties of the vitamin A measurements used are substantial, these findings support the hypothesis that dietary beta-carotene-or some related aspect of a vegetable-rich diet-is protective against invasive cervical cancer.