associated reproductive abnormalities is consistent and is biologically plausible. Liver risk is biologically plausible but less consistent given the negative animal data, but lack of observed effects is not considered as important as observation of effects (see Chapter 10). Overall, the weight of the evidence indicates higher concern with NDGA consumption—a concern that is then applied to chaparral consumption, with the possible exception of chaparral tea.

Chromium picolinate was flagged for review because secondary sources mentioned that its use has been reported in cases of renal toxicity, and because secondary sources discussed its purported effect on insulin regulation and theoretical risk when used with insulin by persons with diabetes (NMCD, 2002). Other signals could have brought this dietary supplement ingredient to the attention of FDA as well. For example, the SN/AEMS documented serious adverse events in individuals ingesting chromium picolinate, including severe seizure, ventricular tachyarrhythmia, and jaundice. These adverse events would have been considered a strong indication that chromium picolinate warranted attention. Chromium picolinate’s widespread prevalence of use, including its common inclusion in many combination dietary supplements, also suggests value in devoting attention to the risk of the use of chromium picolinate as a supplement ingredient.

The renal toxicity cases that signaled chromium picolinate as needing attention were evaluated following the description outlined in Chapter 4. As described in the chromium picolinate prototype monograph, confounders existed, such as concomitant drug consumption and pre-existing conditions, and there was no information about persons experiencing adverse effects ending and then resuming chromium picolinate intake (challenge/ rechallenge). Thus, using the criteria from Chapter 4, the concern level about the signal would be relatively low based on the available information.

More context was provided by reviewing additional adverse event reports from the SN/AEMS, which showed two deaths in individuals taking two or more supplements containing chromium. Again, these reports showed that the users consumed a multitude of supplements and did not include information that led to a strong association (see Chapter 4) with