Bests & Worsts Reviews from Amazon

Unfortunately, Vietnamese cinnamon has massive amounts of coumarin, the potentially liver-damaging substance found in cassia cinnamon. One table showing relative amounts of coumarin is in the middle of this article: [...] If you want daily high-doses of cinnamon for blood sugar control, use "True Cinnamon" otherwise known as "Ceylon Cinnamon". That gives you the benefits of cinnamon without the coumarin. Vietnamese cinnamon should probably be used sparingly, as a culinary treat on the occasional dish, and not in high doses with everything you drink. Edit: Unfortunately, Amazon edited out the URL which was the entire basis for this post. The linked web page contains a chart from a University of Mississippi study on coumarin that documents the following coumarin content of various cinnamons: Coumarin Content | Type of Cinnamon 0.017 g/kg | Ceylon Cinnamon, True Cinnamon. Mexican Cinnamon 2.15 g/kg | Indonesian Cinnamon, Korintje Cinnamon, Padang Cassia 6.97 g/kg | Saigon cinnamon, Vietnamese cassia. Vietnamese cinnamon 0.31 g/kg | Cassia Cinnamon or Chinese Cinnamon Note that Vietnamese cinnamon in this particular sample had almost 23 times as much coumarin as cassia cinnamon!!! Cassia is the one that is most commonly sold in the United States, and most health recommendations are to avoid ingesting large amounts of cassia in favor of "Ceylon / True Cinnamon". So the Vietnamese stuff is off the charts in terms of coumarin content, and I would guess it should be used sparingly for occasional cuisine, not as a daily source for large quantities. I purchased both the Ceylon and Vietnamese, and it's the Ceylon I will be using daily.