holick has been involved in several medical controversies. while at boston university, he was asked to leave the division of dermatology because of his promoting the medical benefits of sun exposure. he accepted research funding for this work from a non-profit tanning bed company, considered by many to be an important potential bias. barbara gilchrest, then head of the department at boston university, called holick's book "shlock science" and holick "a poster boy for the tanning industry".