In all groups, plasma PTH was relatively high. This is a common finding in this population and is likely to be due to their low calcium and high phytate intake [7, 17, 22]. In parallel to findings in Western women, NcAMP was relatively high for its
concurrent plasma PTH concentration in pregnant Gambian women, but both did respond significantly to an acute calcium load. This suggests that, as in Western women, the parathyroid gland in Gambian women adapted to a low calcium intake is responsive to change in plasma calcium, but that other regulatory factors such as PTHrP are involved in calcium and phosphate metabolism during pregnancy. There are several limitations of this study. Firstly, it included only ten women per group, and calcium-loading tests were performed on a cross-sectional basis. SIS3 mouse This will have limited the power of the statistical analyses and conclusions about changes that might be expected within individuals. In addition, during pregnancy,
expansion of the plasma volume may have confounded the observed response particularly of plasma calcium in this and previous studies. This may only partly be corrected for by the use of ptCaAlb. Comparability to the work by Gertner et al. [2] and Kent et al. [1] may be limited due to small differences between protocols. Gertner et al. [2] investigated women after 1 week on a standardized diet of 800 mg calcium per day. In addition, in the studies performed by Kent et al. [1] and Gertner et al. [2], no breakfast was reported as given during learn more the course of the calcium-tolerance test. The breakfast given in this study, although small and low in fat, protein, phytate, calcium and phosphorus content, may have influenced the post-loading response due to a delay in gastric
emptying. In conclusion, there were differences in pPTH, NcAMP and p1,25(OH)2D and bone markers between pregnant, lactating and NPNL Gambian women adapted to a low calcium intake similar to those described in Western women. There was no evidence of pregnancy-induced absorptive Chlormezanone hypercalciuria as observed in Western women with higher calcium intakes. The response to calcium loading indicates that there may be no differences in renal and intestinal calcium economy between pregnant, lactating and non-pregnant, non-lactating women, potentially due to a high degree of calcium conservation Sotrastaurin concentration associated with low intakes. Larger studies designed to assess calcium economy in the intestine and kidney are required to confirm these findings. Acknowledgments This study was supported by the UK Medical Research Council under Programmes U105960371 and U123261351. Ms Tsoi was in receipt of a travel award from The Nestlé Foundation. We thank the staff of MRC Keneba, The Gambia for their help with this study.