Jejunal and ileal adaptation to alterations in dietary calcium. Changes in calcium and magnesium absorption and pathogenetic role of parathyroid hormone and 1,25-dihydroxyvitamin D

D. A. Norman, J. S. Fordtran, L. J. Brinkley, J. E. Zerwekh, M. J. Nicar, S. M. Strowig, C. Y. Pak