Phosphate, Calcium, and Vitamin D: Key Regulators of Fetal and Placental Development in Mammals

Uptake of Phosphate, Calcium, and Vitamin D by the Pregnant Uterus of Sheep in Late Gestation: Regulation by Chorionic Somatomammotropin Hormone

“…Findings from studies across eutherian mammals suggest a critical role for the utero-placental transport of minerals for the establishment and maintenance of pregnancy and for the regulation of fetal-placental growth and development [ 1 , 18 ]. Despite the wide acceptance that phosphate, calcium, and vitamin D are essential during pregnancy, few details exist regarding the hormonal regulation of mechanisms required for transport and metabolism of these fundamental nutrients.…”

“…The utilization of real-time, steady-state quantification of the abundance of calcium in relation to uterine and umbilical blood flow provides a reliable assessment of calcium flow through the feto-placental unit. Phosphate, calcium, and vitamin D signaling pathways are intimately interrelated [ 18 ] and, therefore, placental transport and utilization of these nutrients must not be considered in isolation. Our real-time calcium measurements, in combination with the quantification of phosphate and 25(OH)D in uterine and umbilical samples by colorimetric methods and ELISA, respectively, provide important insights into mineral transport during late gestation in pregnant ewes.…”

“…Prolactin and CSH have been suggested to regulate intestinal calcium absorption, reduce urinary calcium excretion [ 29 ], and stimulate synthesis of PTHrP [ 30 ]. Regulation of intestinal mineral absorption is a critical adaptation to increase the availability of minerals from the maternal circulation [ 18 ], thereby preventing hypocalcemia during periods of high demands of the fetus for minerals, particularly during late gestation. Intrauterine infusions of ovine CSH increase the abundance of STC1 in progestinized ewes [ 31 ], demonstrating important roles for P4 and CSH in the regulation of calcium transport by the ovine uterus.…”

“…Emerging evidence suggests that many of these molecules with important roles in the regulation of mineral transport postnatally are expressed at the ovine maternal-conceptus interface throughout gestation [ 16 , 17 ]. As such, these molecules regulate the active transport of minerals from the maternal circulation to the fetal-placental circulation where they are essential for the appropriate regulation of fetal development [ 1 , 18 ].…”

Associations between maternal vitamin D status and porcine litter characteristics throughout gestation

“…Evidence from multiple species has proven unequivocally that phosphate, calcium, and vitamin D are essential during pregnancy for the appropriate regulation of foetal growth (reviewed by [ 8 , 9 ]). Yet, the understanding of how maternal vitamin D status changes across gestation, and the association between this and pregnancy outcome and foetal development in the pig remains poorly understood.…”