In the present study, we show for the first time the presence of calcitriol-specific binding sites in hypertonic extracts of cells isolated from human fetal small intestine and colon from 13–21 weeks of gestation. Woolf plot analysis of the binding characteristics revealed the presence of a single class of high affinity receptors. The presence of specific receptors for calcitriol in fetal intestine and colon opens interesting possibilities as to the role of this hormone in human gut development.
