EXHIBIT 32.1


           CERTIFICATE PURSUANT TO 18 U.S.C. SECTION 1350, AS ENACTED
                BY SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


         I, Paul L. Berns, the President and Chief Executive Officer of Bone
Care International, Inc. (the "Company"), certify, pursuant to 18 U.S.C. Section
1350, that (i) the Quarterly Report on Form 10-Q of the Company for the quarter
ended December 31, 2003 (the "Form 10-Q") fully complies with the requirements
of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and (ii) the
information contained in the Form 10-Q fairly presents, in all material
respects, the financial condition and results of operations of the Company.


                                    /S/  PAUL  L. BERNS
                                    -------------------------------------
                                    Paul L. Berns
                                    President and Chief Executive Officer
February 10, 2004






                                      -18-