Vitamin D and Calcium Homeostasis in Infants with Urolithiasis

2019 ◽  
pp. 75-81
Author(s):  
Agnieszka Szmigielska ◽  
Małgorzata Pańczyk-Tomaszewska ◽  
Małgorzata Borowiec ◽  
Urszula Demkow ◽  
Grażyna Krzemień
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis

scholarly journals Prevalence of Vitamin D Deficiency and Calcium Homeostasis in Saudi Children

2016 ◽  
Vol 8 (4) ◽  
pp. 461-467 ◽  
Author(s):  
Adnan M. Al Shaikh ◽  
Bahaa Abaalkhail ◽  
Ashraf Soliman ◽  
Ibrahim Kaddam ◽  
Khalid Aseri ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Calcium Homeostasis

Bone turnover, calcium homeostasis, and vitamin D status in Danish vegans

2018 ◽  
Vol 72 (7) ◽  
pp. 1046-1054 ◽  
Author(s):  
Tue H. Hansen ◽  
Marie T. B. Madsen ◽  
Niklas R. Jørgensen ◽  
Arieh S. Cohen ◽  
Torben Hansen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Bone Turnover ◽  
Calcium Homeostasis ◽  
Vitamin D Status

scholarly journals Transgenic Mice Overexpressing Human Fibroblast Growth Factor 23 (R176Q) Delineate a Putative Role for Parathyroid Hormone in Renal Phosphate Wasting Disorders

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 5269-5279 ◽  
Author(s):  
Xiuying Bai ◽  
Dengshun Miao ◽  
Jiarong Li ◽  
David Goltzman ◽  
Andrew C. Karaplis
Keyword(s):  
Vitamin D ◽  
Growth Factor ◽  
Transgenic Mice ◽  
Fibroblast Growth Factor ◽  
Calcium Homeostasis ◽  
Fibroblast Growth Factor 23 ◽  
Fibroblast Growth ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D3 ◽  
Circulating Levels

Abstract Fibroblast growth factor 23 (FGF23) is a recently characterized protein likely involved in the regulation of serum phosphate homeostasis. Increased circulating levels of FGF23 have been reported in patients with renal phosphate-wasting disorders, but it is unclear whether FGF23 is the direct mediator responsible for the decreased phosphate transport at the proximal renal tubules and the altered vitamin D metabolism associated with these states. To examine this question, we generated transgenic mice expressing and secreting from the liver human FGF23 (R176Q), a mutant form that fails to be degraded by furin proteases. At 1 and 2 months of age, mice carrying the transgene recapitulated the biochemical (decreased urinary phosphate reabsorption, hypophosphatemia, low serum 1,25-dihydroxyvitamin D3) and skeletal (rickets and osteomalacia) alterations associated with these disorders. Unexpectantly, marked changes in parameters of calcium homeostasis were also observed, consistent with secondary hyperparathyroidism. Moreover, in the kidney the anticipated alterations in the expression of hydroxylases associated with vitamin D metabolism were not observed despite the profound hypophosphatemia and increased circulating levels of PTH, both major physiological stimuli for 1,25-dihydroxyvitamin D3 production. Our findings strongly support the novel concept that high circulating levels of FGF23 are associated with profound disturbances in the regulation of phosphate and vitamin D metabolism as well as calcium homeostasis and that elevated PTH levels likely also contribute to the renal phosphate wasting associated with these disorders.

Calcium homeostasis

2015 ◽  
Author(s):  
Francesco Trepiccione ◽  
Giovambattista Capasso
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Calcium Homeostasis ◽  
Calcineurin Inhibitors ◽  
Blood Levels ◽  
Active Vitamin ◽  
Active Vitamin D

Ca2+ homeostasis is achieved through a fine balance among three main organs: the intestine, the kidney, and bone. Blood levels of Ca2+ are accurately tuned through the Ca2+ sensing receptors and regulated by several hormones, including parathyroid hormone (PTH), active vitamin D, and calcitonin. The most recent findings in Ca2+ handling are described. The role of the Ca2+ sensing receptor, as well as Klotho, a new player participating in Ca2+ homeostasis, are described. Finally, the effects of diuretics, calcineurin inhibitors, and the link between hypertension and Ca2+ metabolism are reviewed.

scholarly journals Evidence for a Role of Prolactin in Calcium Homeostasis: Regulation of Intestinal Transient Receptor Potential Vanilloid Type 6, Intestinal Calcium Absorption, and the 25-Hydroxyvitamin D3 1α Hydroxylase Gene by Prolactin

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 2974-2984 ◽  
Author(s):  
Dare V. Ajibade ◽  
Puneet Dhawan ◽  
Adam J. Fechner ◽  
Mark B. Meyer ◽  
J. Wesley Pike ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis ◽  
Calcium Transport ◽  
Transient Receptor Potential ◽  
Prolactin Receptor ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Calbindin D9k ◽  
Intestinal Calcium Transport ◽  
Transient Receptor

Increased calcium transport has been observed in vitamin D-deficient pregnant and lactating rats, indicating that another factor besides 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is involved in intestinal calcium transport. To investigate prolactin as a hormone involved in calcium homeostasis, vitamin D-deficient male mice were injected with 1,25(OH)2D3, prolactin, or prolactin + 1,25(OH)2D3. Prolactin alone (1 μg/g body weight 48, 24, and 4 h before termination) significantly induced duodenal transient receptor potential vanilloid type 6 (TRPV6) mRNA (4-fold) but caused no change in calbindin-D9k. Combined treatment with 1,25(OH)2D3 and prolactin resulted in an enhancement of the 1,25(OH)2D3 induction of duodenal TRPV6 mRNA, calbindin-D9k mRNA, and an induction of duodenal calcium transport [P < 0.05 compared with 1,25(OH)2D3 alone]. Because lactation is associated with an increase in circulating 1,25(OH)2D3, experiments were done to determine whether prolactin also has a direct effect on induction of 25-hydroxyvitamin D3 1α hydroxylase [1α(OH)ase]. Using AOK B-50 cells cotransfected with the prolactin receptor and the mouse 1α(OH)ase promoter −1651/+22 cooperative effects between prolactin and signal transducer and activator of transcription 5 were observed in the regulation of 1α(OH)ase. In addition, in prolactin receptor transfected AOK B-50 cells, prolactin treatment (400 ng/ml) and signal transducer and activator of transcription 5 significantly induced 1α(OH)ase protein as determined by Western blot analysis. Thus, prolactin, by multiple mechanisms, including regulation of vitamin D metabolism, induction of TRPV6 mRNA, and cooperation with 1,25(OH)2D3 in induction of intestinal calcium transport genes and intestinal calcium transport, can act as an important modulator of vitamin D-regulated calcium homeostasis.

scholarly journals Impact of intercurrent illness on calcium homeostasis in children with hypoparathyroidism: a case series

2017 ◽  
Vol 6 (8) ◽  
pp. 589-594 ◽  
Author(s):  
A Chinoy ◽  
M Skae ◽  
A Babiker ◽  
D Kendall ◽  
M Z Mughal ◽  
...  
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Homeostasis ◽  
Calcium Supplementation ◽  
Case Series ◽  
Close Monitoring ◽  
Oral Calcium ◽  
Calcium Supplements ◽  
Intercurrent Illness ◽  
The Impact

Background Hypoparathyroidism is characterised by hypocalcaemia, and standard management is with an active vitamin D analogue and adequate oral calcium intake (dietary and/or supplements). Little is described in the literature about the impact of intercurrent illnesses on calcium homeostasis in children with hypoparathyroidism. Methods We describe three children with hypoparathyroidism in whom intercurrent illnesses led to hypocalcaemia and escalation of treatment with alfacalcidol (1-hydroxycholecalciferol) and calcium supplements. Results Three infants managed with standard treatment for hypoparathyroidism (two with homozygous mutations in GCMB2 gene and one with Sanjad-Sakati syndrome) developed symptomatic hypocalcaemia (two infants developed seizures) following respiratory or gastrointestinal illnesses. Substantial increases in alfacalcidol doses (up to three times their pre-illness doses) and calcium supplementation were required to achieve acceptable serum calcium concentrations. However, following resolution of illness, these children developed an increase in serum calcium and hypercalciuria, necessitating rapid reduction to pre-illness dosages of alfacalcidol and oral calcium supplementation. Conclusion Intercurrent illness may precipitate symptomatic hypocalcaemia in children with hypoparathyroidism, necessitating increase in dosages of alfacalcidol and calcium supplements. Close monitoring is required on resolution of the intercurrent illness, with timely reduction of dosages of active analogues of vitamin D and calcium supplements to prevent hypercalcaemia, hypercalciuria and nephrocalcinosis.

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