Iron

http://classyfire.wishartlab.com/tax_nodes/C0000001
http://classyfire.wishartlab.com/tax_nodes/C0000422
http://classyfire.wishartlab.com/tax_nodes/C0000426
http://classyfire.wishartlab.com/tax_nodes/C0000426
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:82664
http://www.hmdb.ca/metabolites/HMDB0015531
http://www.genome.jp/dbget-bin/www_bget?cpd:C00023
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=23925
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46509190
https://www.chemspider.com/Chemical-Structure.22368.html
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=262150
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=18248
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP001313
http://www.pharmgkb.org/drug/PA450087
http://www.rxlist.com/cgi/generic/fedex.htm
https://www.drugs.com/mtm/ferrous-gluconate.html
http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/iro_0149.shtml
https://en.wikipedia.org/wiki/Iron