Fig. 3. Individual responses in calcitropic hormones at day 4 in response to graded intakes of dietary protein (n = 8 healthy young women). The order of treatments was randomized. The upper limits of normal are represented by horizontal dashed lines. NcAMP = nephrongenous cyclic adenosine monophosphate, a bioindicator of PTH activity. GF = glomerular filtration. (Reproduced with permission from [241].)