Abstract Patients with multiple myeloma have transcortin levels lower than normal. This is due in essence to a subgroup of patients producing IGG heavy chains with lambda light chains. Patients producing IGG with predominantly kappa light chains have almost normal transcortin levels. On the other hand, the binding activity of the steroid binding beta globulin (SBβG) of the kappa type of multiple myeloma is significantly higher than the steroid binding of the lambda type of multiple myeloma. The serum levels of vitamin D binding protein (DBP) fall in the normal range.