Beta-carotene supplements are not advised among healthy individuals, unless they suffer from or are at risk of vitamin A deficiency. Beta-carotene supplementation results in a greater increase of beta-carotene blood concentration than beta-carotene rich foods. A 20 mg/d supplement of beta-carotene is associated with blood concentrations high enough to increase a patient’s risk of lung cancer, while the same quantity obtained from foods was not associated with lung cancer risk. Additionally, 30 mg/d of beta-carotene supplement was associated with blood concentrations 5 times greater than that of 29 mg/d of beta-carotene from carrots.
The consumption of 5 or more daily servings of fruits and vegetables is recommended by “National Cancer Institute’s Five-A-Day for a Better Health program” and “Canada’s Food Guide for Healthy Eating.” Eating a variety of 5 fruits and vegetables per day provides the individual with about 5.2 to 6 mg/day of food based beta-carotene. This allows plasma carotenoid levels to rise above a range represented in studies which were associated with a lower risk of cancer and all-cause mortality compared to those with a lower food based carotenoid levels.