2HMTBa = 2-hydroxy-4-methylthio butanoic acid. The Zn(HMTBa)2,
Cu(HMTBa)2, and Mn(HMTBa)2 are chelates of 1 molecule of mineral
and 2 molecules of HMTBa (MINTREX; Novus International) and FeGly
is a chelate of 1 molecule of Fe and 1 molecule of glycine (MAAC; Novus
International). The molecular weight of Zn(HMTBa)2, Cu(HMTBa)2,
Mn(HMTBa)2, and FeGly are 366, 364, 355, and 131 g/mol, respectively