Use of a composition comprising a compound of any of formulae I, II, Ila, III and Illa; or a combination thereof wherein each R<;SUB>;1 <;/SUB>;is independently C<;SUB>;7-11 <;/SUB>;alkyl; A and B are independently H or CO-R<;SUB>;1<;/SUB>;; R<;SUB>;2 <;/SUB>;is H or C<;SUB>;1-4 <;/SUB>;alkyl; M is a metal monocation (k=1) or dication (k=2); Y is 0 or NH; and Z is 0, NH, CH<;SUB>;2<;/SUB>;O or a bond; for the manufacture of a medicament for stimulating erythropoiesis. Preferably, the composition further comprises human erythroporietin.