I add 1 teaspoon of ceylon cinnamon powder to oats cereal everyday.heard coumarin in cinnamon affects liver. is my intake of cinnamon safe quantity?

YES-ceylon form safe: There are 2 forms of cinnamon, Ceylon (called true cinnamon),which has little coumarin,and Cassia,which has higher amounts of coumarin which in large quantities can cause liver damage in a subset of those who are sensitive. I can't find any info on whether 1 tsp of Cassia is considered a large quantity, but there's absolutely no reason to worry about Ceylon cinnamon.See http://tinyurl.com/cwmgeeh