Intestinal absorption of calcium and phosphorus: Experiments on interaction between vitamin D and adrenocortical hormone

1975 ◽  
Vol 42 (1) ◽  
pp. 1-9 ◽  
Author(s):  
M. Teotia ◽  
S. P. S. Teotia ◽  
T. Raman ◽  
N. L. Sharma ◽  
R. K. Singh
Keyword(s):  
Vitamin D ◽  
Intestinal Absorption ◽  
Calcium And Phosphorus ◽  
Adrenocortical Hormone

Effect of metabolic acidosis in intestinal absorption of calcium and phosphorus

1980 ◽  
Vol 239 (6) ◽  
pp. G480-G484 ◽  
Author(s):  
U. Gafter ◽  
J. A. Kraut ◽  
D. B. Lee ◽  
V. Silis ◽  
M. W. Walling ◽  
...  
Keyword(s):  
Vitamin D ◽  
Metabolic Acidosis ◽  
Plasma Level ◽  
Intestinal Absorption ◽  
Metabolic Balance ◽  
Vitamin D Metabolism ◽  
Calcium And Phosphorus ◽  
Control Plasma ◽  
P Absorption

To investigate the effect of metabolic acidosis on intestinal calcium (Ca) and phosphorus (P) absorption and vitamin D metabolism, metabolic balance studies and in vitro gut sac uptake of 45Ca and [32P]phosphate were performed in rats maintained on low-Ca and moderately low-P diet and fed NH4Cl for 3 or 9 days and pair-fed controls. Plasma 1,25(OH)2D concentration was measured in the rats fed NH4Cl for 9 days and their controls. Net Ca and P absorption was 87–92% in the acidotic rats and did not differ from control. Moreover, gut sac uptakes of 45Ca and [32P]phosphate were not different from control. Plasma 1,25(OH)2D was higher in the ammonium chloride-fed rats than in controls (213 +/- 44 vs. 110 +/- 12 pg/ml), and serum P was lower in the acidotic animals (4.6 +/- 0.7 vs. 7.6 +/- 0.3 mg/dl). These data indicate that metabolic acidosis does not depress the augmented intestinal absorption of calcium and phosphorus noted during their dietary deprivation nor reduce the plasma level of 1,25(OH)2D.

scholarly journals More Than Bone Health: The Many Roles for Vitamin D

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2388
Author(s):  
Emma Beckett
Keyword(s):  
Vitamin D ◽  
Intestinal Absorption ◽  
Calcium Homeostasis ◽  
Bone Health ◽  
Bone Mineralization ◽  
Calcium Mobilization ◽  
Renal Reabsorption ◽  
Calcium And Phosphorus ◽  
The Many

Vitamin D is well known for its important roles in maintaining calcium homeostasis and bone mineralization via the regulation of calcium mobilization and renal reabsorption, and the intestinal absorption of both calcium and phosphorus [...]

Effect of Bicarbonate Feeding on Intestinal Absorption of Calcium and Vitamin D Metabolism in Rats

1985 ◽  
Vol 68 (1) ◽  
pp. 97-100 ◽  
Author(s):  
U. Gafter ◽  
S. Edelstein ◽  
J. Levi
Keyword(s):  
Vitamin D ◽  
Plasma Level ◽  
Intestinal Absorption ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Phosphorus Absorption ◽  
Calcium And Phosphorus

1. The effect of bicarbonate (NaHCO3) feeding on intestinal absorption of calcium and phosphorus and vitamin D metabolism was investigated. Gut sac uptake of 45Ca and [32P]phosphate in vitro, as well as the plasma level of vitamin D metabolites, was determined in rats fed with NaHCO3 for 9 days and their pair-fed controls. 2. Duodenal uptake of 45Ca and [32P]phosphate by alkalotic rats was less than duodenal uptake by controls. 1,25(OH)2D plasma level was much higher in alkalotic rats than in their controls, and 25(OH)D slightly higher than in controls. 3. These data suggest that NaHCO3 feeding causes a substantial increase in 1,25(OH)2D plasma level, but interferes with calcium and phosphorus absorption in the duodenum.

Vitamin D Deficiency and Intoxication - A concern either way

JMS SKIMS ◽  
2011 ◽  
Vol 14 (2) ◽  
pp. 40-42
Author(s):  
Muzafar Maqsood Wani ◽  
Imtiaz Ahmed Wani
Keyword(s):  
Vitamin D ◽  
Cell Growth ◽  
Bone Turnover ◽  
Secondary Hyperparathyroidism ◽  
Vitamin D Deficiency ◽  
Bone Mineralization ◽  
Normal Blood ◽  
Blood Levels ◽  
Calcium And Phosphorus ◽  
Biologic Function

Major biologic function of activated vitamin D is to maintain normal blood levels of calcium and phosphorus, thus regulating bone mineralization. Research suggests that vitamin D may help in immunomodulation, regulating cell growth and 1,4 differentiation as well as some diverse unspecified functions. Overt vitamin D deficiency leads to hypocalcaemia, secondary hyperparathyroidism and increased bone turnover, which in prolonged and severe cases may cause rickets in children and osteomalacia in elderly.... JMS 2011;14(2):40-42

Intestinal absorption of calcium: role of dietary phosphate and vitamin D

1981 ◽  
Vol 241 (1) ◽  
pp. G49-G53
Author(s):  
N. Brautbar ◽  
B. S. Levine ◽  
M. W. Walling ◽  
J. W. Coburn
Keyword(s):  
Vitamin D ◽  
Intestinal Absorption ◽  
Vitamin D3 ◽  
Control Groups ◽  
Dihydroxyvitamin D3 ◽  
Dietary Phosphorus ◽  
P Concentration ◽  
Dietary Phosphate ◽  
Intestinal Ca Absorption

The intestinal absorption of calcium (Ca) has been shown to depend on vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], and dietary phosphorus (P) concentration. This study was designed to evaluate the role of dietary P independent of vitamin D3 or 1,25(OH)2D3. Vitamin D-deficient rats were studied during dietary P restriction and were compared with control groups raised on a normal-phosphorus diet (NP). Balance studies were sued. Net intestinal Ca absorption was significantly lower with dietary P restriction compared with the NP group. This malabsorption of Ca was corrected by the administration of either D3 for 1,25(OH)2D3, despite hypophosphatemia. Everted gut sacs showed a marked reduction in the uptake of 45Ca in the duodenum, jejunum, and ileum during dietary P restriction. We concluded that dietary P concentration plays a major role in intestinal Ca absorption in the vitamin D-deficient rats. These findings suggest an effect of the low-phosphate diet on the vitamin D-dependent, Ca-transport mechanism.

scholarly journals High stocking density alters bone-related calcium and phosphorus metabolism by changing intestinal absorption in broiler chickens

2018 ◽  
Vol 97 (1) ◽  
pp. 219-226 ◽  
Author(s):  
Z.W. Sun ◽  
Q.H. Fan ◽  
X.X. Wang ◽  
Y.M. Guo ◽  
H.J. Wang ◽  
...  
Keyword(s):  
Intestinal Absorption ◽  
Broiler Chickens ◽  
Stocking Density ◽  
Phosphorus Metabolism ◽  
Calcium And Phosphorus

scholarly journals The effect of disodium ethane-1-hydroxy-1,1-diphosphonate on the metabolism of calcitriol in chicks

1987 ◽  
Vol 243 (1) ◽  
pp. 75-78 ◽  
Author(s):  
C Lidor ◽  
M S Meyer ◽  
R H Wasserman ◽  
S Edelstein
Keyword(s):  
Vitamin D ◽  
Urinary Excretion ◽  
Intestinal Absorption ◽  
Binding Protein ◽  
Sole Source ◽  
Treated Group ◽  
Response To Treatment ◽  
Vitamin D Metabolism ◽  
Calbindin D28k ◽  
25 Hydroxycholecalciferol

Decreased intestinal absorption of Ca2+ occurs in response to treatment with disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP). The effect is due to decreased 1-hydroxylation of calcidiol (25-hydroxycholecalciferol) in the kidney. In an attempt to establish whether impairment of vitamin D metabolism at steps beyond kidney hydroxylation occurs due to treatment with EHDP, chicks were depleted of vitamin D and were treated with calcitriol (1,25-dihydroxycholecalciferol) as their sole source of the vitamin. The chicks were then divided into two groups, one being treated with EHDP while the second group served as control. Intestinal absorption of Ca2+ in the EHDP-treated group was found to be impaired, along with decreases in concentrations of calbindin D28K (the 28,000-Mr vitamin D-dependent Ca2+-binding protein). When the chicks were dosed with [3H]calcitriol, significantly lower concentrations of the sterol were detected in the duodena of EHDP-treated birds. Measurement of levels of receptors for calcitriol in duodena showed no difference between groups, but levels of calcitriol in sera were considerably lower in the EHDP-treated group along with the elevated biliary and urinary excretion of glucuronidated conjugates. It is therefore concluded that treatment with EHDP results in increased catabolism of calcitriol in addition to the known suppression of the renal production of the hormone.

scholarly journals Characteristics of the rat liver microsomal enzyme system converting cholecalciferol into 25-hydroxycholecalciferol. Evidence for the participation of cytochrome p-450

1979 ◽  
Vol 184 (3) ◽  
pp. 491-499 ◽  
Author(s):  
T C Madhok ◽  
H F DeLuca
Keyword(s):  
Vitamin D ◽  
White Light ◽  
Microsomal Fraction ◽  
Enzyme System ◽  
Initial Reaction ◽  
Microsomal Enzyme ◽  
Reaction Velocity ◽  
Calcium And Phosphorus ◽  
Cytochrome P 450 ◽  
25 Hydroxycholecalciferol

Properties of the rat hepatic cholecalciferol 25-hydroxylase have been studied. An assay system has been developed in which 25-hydroxycholecalciferol production is linear for at least 2h in both homogenates and microsomal fraction. Furthermore, the initial reaction velocity is linearly related to the amount of liver tissue or microsomal fraction. This enzyme system also metabolizes an analogue of cholecalciferol, namely dihydrotachysterol 3, into 25-hydroxydihydrotachysterol 3. The 25-hydroxylase is in the microsomal fraction and not in mitochondria. It has a Km of 44 nM for cholecalciferol and 360 nM for dihydrotachysterol 3. Its activity is not altered by dietary concentrations of calcium and phosphorus. Vitamin D-deficient rats have higher activities of the hepatic 25-hydroxylase than those receiving 25 ng of cholecalciferol daily. The 25-hydroxylase is inhibited by metyrapone. An atmosphere of CO/O2 (9:1, v/v) inhibits the reaction by 87%. This inhibition is partially reversed by white light. Additionally, cholecalciferol and 25-hydroxycholecalciferol competitively inhibit aminopyrine demethylase. These results support the idea that the cholecalciferol 25-hydroxylase is a cytochrome P-450-dependent mono-oxygenase.

Sign in / Sign up

Export Citation Format

Share Document