Poisonous reasons for mixing shallots with tofu: calcium in tofu and oxalic acid in shallots will combine to form a white precipitate-calcium oxalate, which makes it difficult for the human body to absorb calcium. Comments: If you don't eat it with tofu, the oxalic acid in shallots will be directly absorbed by the human body and then combined with calcium in the body to form stones. Instead of increasing the risk of stones, it is better to waste a little calcium in tofu. In addition, there is more than one kind of food containing oxalic acid, and most vegetables contain oxalic acid, such as bamboo shoots, water bamboo, spinach, amaranth, etc ... Compared with them, shallots contain limited oxalic acid and will not have a great impact on calcium in tofu.