Sunscreen May Promote Skin Cancer Growth Because many products contain vitamin A By Kate Seamons, Newser Staff Posted May 24, 2010 7:13 AM CDT Updated May 29, 2010 6:35 AM CDT 20 comments Comments On the Beach (©di_the_huntress) (Newser) – Sunscreen may not be the great protector it's cracked up to be: A study of 500 of the most popular sunscreen products found that nearly half may actually promote the growth of skin cancer. That's because they contain some form of vitamin A, which may accelerate the rate at which malignant cells develop when used on skin exposed to sunlight. In their annual report, researchers at Environmental Working Group point to a decade-old FDA study they discovered on the vitamin's photocarcinogenic properties. "In that year-long study, tumors and lesions developed up to 21% faster in lab animals coated in a vitamin A-laced cream than animals treated with a vitamin-free cream," the report said. AOL News notes that the FDA has denied knowing about vitamin A-related dangers, but EWG maintains that "there was enough evidence 10 years ago for FDA to caution consumers against the use of vitamin A in sunscreens." EWG dubbed a paltry 39 of those reviewed safe and effective; view them here.