A City Guide To Fuxin for Vitamin supplements are a growth industry. However, what is the evidence base as to their effectiveness? Do vitamin supplements work in the same way as vitamins contained in dietary foods do? To address the first question, the United States Preventive Services Task Force USPSTF an expert group formed to review research evidence in order to make informed health recommendations conducted two largescale reviews of studies of vitamin supplements published between and One reviewed the evidence regarding reduced risk of cardiovascular disease USPSTF and the other reviewed evidence in relation to reduced risk of breast, lung, colon and prostate cancer Morris and Carson They found that even well-designed randomised controlled trials comparing vitamin supplements with an identical-looking placebo pill, in terms of subsequent development of disease, were inconclusive in their findings. Worryingly, they report compelling evidence’ that beta-carotene supplements were associated with increased lung cancer risk, and subsequent death in smokers. The reviewers noted that it tended to be poorly designed studies that claimed to have found associations between vitamin supplementation and reduced disease risk. For example, observational studies reporting reduced breast cancer risk and vitamin A intake generally failed to control for other aspects of their sample’s behaviour, such as their general dietary intake or exercise behaviour. Other evidence, such as reduced risk of colon cancer among those taking folic acid supplements, was based on retrospective reports of those affected/not affected, rather than on long-term prospective follow-up studies of initially healthy individuals. Such findings therefore also need to be interpreted with caution. A City Guide To Fuxin 2016.