Data Views Plants (>= 1 Chemical): 548 All Chemicals: 22 CSV Excel PDF Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column Chemical Dosage References TANNIC-ACID --* ZINC 50 mg/man/3x/dayMartindale's 28th *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.