Vitamin and provitamin A levels in epithelial cancers: a preliminary study.

A major physiological role of retinoids is the regulation of epithelial and epidermal cell differentiation. A total of 285 patients with clinically and histopathologically confirmed diagnosis of various carcinomas (untreated) were selected for the study. The control values of serum beta-carotene and vitamin A levels were established from 50 subjects free of any known pathology. The controls were matched for age and sex. The mean serum levels of beta-carotene and vitamin A have shown a significant difference (p less than 0.001) in all the cancers compared with the controls. In cancer of the oral cavity, the males showed significantly lower levels (p less than 0.01) compared with their female counterparts. In cancer of the lung, however, the mean serum levels of beta-carotene and vitamin A were higher in males compared with females (p less than 0.02). Our results suggest a possible association between vitamin A and epithelial cancer, but whether the deficiency is the cause of the disease or if it is due to the tumor remains unknown.