Chromium, which is important for insulin function, is often used in weight loss supplements due to research suggesting modest weight loss benefit—although the evidence is mixed, ConsmerLab.com claims. Hexavalent chromium, which was at the center of the movie Erin Brockovich, should not normally be found in supplements. Legal limits have not been established for the amount of hexavalent chromium in supplements, but the state of California is considering an aggressive public health goal limiting hexavalent chromium in drinking water to only 0.06 ppb—about 0.12 mcg per day. The California limit is based on a one in 1 million lifetime cancer risk extrapolated from studies in mice.
ConsumerLab.com found that one widely sold weight loss pill delivered 26.4 mcg of hexavalent chromium per day, 220 times the maximum amount one could be exposed to from daily intake of water under California’s proposed limit. A chromium supplement delivered 10.9 mcg in a daily serving and another nationally known weight loss supplement contained up to 3.2 mcg per daily serving. The contaminant was confirmed in three independent laboratories using blinded samples. Although no legal limit has been established, ConsumerLab.com requires that the chromium in supplements be 99.9% pure. Its tests showed these three products contained 6%, 2% and 0.64%, respectively, of their total chromium as hexavalent chromium, all exceeding ConsumerLab.com’s limit. The specific risks associated with these amounts are not known, but it seems prudent to avoid such exposure, particularly as other chromium-containing products are available that passed ConsumerLab.com testing.