A randomized, 12-year primary-prevention trial of beta carotene supplementation for nonmelanoma skin cancer in the physician's health study.

Regular intake of beta-carotene supplements may have no preventive effect on nonmelanoma skin cancer, including basal and squamous cell carcinoma.

This study investigated the association between supplementation with beta-carotene and the risk of developing first non-melanoma skin cancer, including basal cell carcinoma and squamous cell carcinoma. Researchers administered either placebo or beta-carotene supplements to 22,071 healthy male subjects between the ages of 40-84 years for 12 years. The nonmelanoma skin cancer odds ratio was also estimated in each participant in this study.

Researchers observed that the use of beta-carotene supplements had no effect on the risk of developing first nonmelanoma skin cancer. The results of this study do not support the hypothesis that supplementation with beta-carotene may protect individuals against nonmelanoma skin cancer.