Researchers examined the tolerably daily intake (TDI) of coumarin, a naturally occurring substance found in a wide variety of plants (tonka bean, vanilla) with hepatotoxic (causing damage to the liver) and carcinogenic (cancer causing) properties. An analysis of clinical data on hepatoxicity from patients treated with coumarin as a medicinal drug was analyzed and resulted in a derived TDI of 0.1mg/kg. Authors suggest that dietary exposure to coumarin is considerable and may be attributable to the popular spice used for cookies and sweet dishes known as cassia cinnamon. Data in this study suggests that Cassia (Chinese) cinnamon may cause hepatotoxicity therefore it may be better to consume Ceylon cinnamon for supplementation. (50)
