Influence of estrogen on renal vitamin D hydroxylases and serum 1alpha,25-(OH)2D3 in chicks.

1978 ◽  
Vol 235 (3) ◽  
pp. E338 ◽  
Author(s):  
J W Pike ◽  
E Spanos ◽  
K W Colston ◽  
I MacIntyre ◽  
M R Haussler
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Vitamin D3 ◽  
Steroid Treatment ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D3 ◽  
Chick Kidney ◽  
24,25 Dihydroxyvitamin D3

The influence of estrogen on the metabolism of 25-hydroxyvitamin D3 was studied in 2- to 5-wk-old chicks. Single injections of at least 500 microgram diethylstibestrol (DES) increased the conversion of 25-hydroxyvitamin D3 to 1alpha,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3) and suppressed the production of 24,25-dihydroxyvitamin D3 in chick kidney homogenates. Acute (one 5-mg) injections of testosterone or progesterone did not enhance the 25-hydroxyvitamin D3-1alpha-hydroxylase, indicating specificity. However, chronic pretreatment with DES appeared to allow the potentiation of previously unstimulatory steroids such as progesterone and testosterone. In addition, the hormonal metabolite of vitamin D3, 1alpha,25-(OH)2D3, was measured in 4- to 6-wk chick plasma after steroid treatment. Greater than 1 mg DES per day for 5 days was necessary to enhance the circulating level of 1alpha,25-(OH)2D3; testosterone alone had no effect. This elevation was rapid, occurring within 12--24 h after injection. These data suggest that estrogen (as evidenced by DES treatment) is a modulator of vitamin D metabolism along with other known regulators such as parathyroid hormone, phosphate, and 1alpha,25-(OH)2D3. The mechanism of the regulation is as yet unknown.

The Effect of Vitamin D and Its Metabolites on Fracture Repair in Chicks

1983 ◽  
Vol 65 (4) ◽  
pp. 429-436 ◽  
Author(s):  
S. Dekel ◽  
R. Salama ◽  
S. Edelstein
Keyword(s):  
Vitamin D ◽  
Bone Formation ◽  
Vitamin D3 ◽  
Fracture Repair ◽  
Control Group ◽  
Clinical Implications ◽  
Torsional Stress ◽  
Active Vitamin ◽  
Dihydroxyvitamin D3 ◽  
24,25 Dihydroxyvitamin D3

1. One-day-old chicks were depleted of vitamin D. At 3 weeks their right tibiae, and those of a control group given vitamin D3, were fractured and pinned. After fracture the controls were kept on vitamin D3. Another group was left vitamin D-deficient. The remaining depleted chicks, divided into four groups, were given vitamin D3, 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or a combination of 24,25(OH)2D3 and 1,25(OH)2D3. 2. The callus obtained after 9 and 14 days was subjected to torsional stress. The callus of chicks given vitamin D continuously showed the greatest resistance, whereas that of vitamin D-deficient chicks showed the smallest resistance. Repletion with either vitamin D3 or its metabolites increased the strength of the callus. Repletion with the combination of 24,25(OH)2D3 and 1,25(OH)2D3 produced the most marked results, in that the callus was even stronger than that of chicks replete with vitamin D3. 3. It is concluded that 24,25(OH)2D3 is essential for bone formation in addition to the known active vitamin D metabolite 1,25(OH)2D3, and the possible clinical implications of these findings are discussed.

Effects of vitamin D and diet magnesium on magnesium metabolism

1980 ◽  
Vol 239 (6) ◽  
pp. E515-E523 ◽  
Author(s):  
B. S. Levine ◽  
N. Brautbar ◽  
M. W. Walling ◽  
D. B. Lee ◽  
J. W. Coburn
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Tubular Reabsorption ◽  
Transport Processes ◽  
Separate Experiment ◽  
Dihydroxyvitamin D3 ◽  
Magnesium Metabolism ◽  
1,25 Dihydroxyvitamin D3 ◽  
24,25 Dihydroxyvitamin D3

Effects of 6-9 days of vitamin D3 (D3), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], or 1,24,25-trihydroxyvitamin D3 [1,24,25(OH)3D3] on Mg metabolism were studied in vitamin D-deficient (-D) rats. Mg absorption expressed as percent intake increased with 1,25(OH)2D3 and 1,24,25(OH)3D3. Urinary Mg (UMg) increased with no change in serum Mg (SMg) or Mg balance. 1,25(OH)2D3 was threefold more potent than 1,24,25(OH)3D3 in raising serum Ca and Mg absorption. In a separate experiment in pair-fed rats given D3, 1,25-(OH)2D3, or 1,24,25(OH)3D3, the diet contained either 0.03 or 0.2% Mg; 1,25(OH)2D3 and D3 lowered SMg after 3 days; UMg increased after 24 h to remain elevated. D3 and 1,25(OH)2D3 augmented Mg absorption; feeding 0.2% Mg lowered Mg absorption in -D animals. All sterols augmented Mg absorption in -D rats; both the earlier action of 1,25(OH)2D3 and 1,24,25(OH)3D3 suggests that 1-hydroxylation is necessary. Suppressed Mg absorption with 0.2% Mg in -D rats suggests two transport processes, with one vitamin D dependent. Higher UMg with decreased SMg with 1,25(OH)2D3 suggests reduced tubular reabsorption.

scholarly journals Differential Effects of Oral Boluses of Vitamin D2 vs Vitamin D3 on Vitamin D Metabolism: A Randomized Controlled Trial

2019 ◽  
Vol 104 (12) ◽  
pp. 5831-5839 ◽  
Author(s):  
Adrian R Martineau ◽  
Kenneth E Thummel ◽  
Zhican Wang ◽  
David A Jolliffe ◽  
Barbara J Boucher ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Bolus Dose ◽  
Total Serum ◽  
Vitamin D2 ◽  
Serum Concentrations ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D3 ◽  
Differential Effects ◽  
The Mean

Abstract Context Vitamin D2 and vitamin D3 have been hypothesized to exert differential effects on vitamin D metabolism. Objective To compare the influence of administering vitamin D2 vs vitamin D3 on metabolism of vitamin D3. Methods We measured baseline and 4-month serum concentrations of vitamin D3, 25-hydroxyvitamin D3 [25(OH)D3], 25-hydroxyvitamin D2, 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3], 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], and 4β,25-dihydroxyvitamin D3 [4β,25(OH)2D3] in 52 adults randomized to receive a total of four oral bolus doses of 2.5 mg vitamin D2 (n = 28) or vitamin D3 (n = 24) over four months. Metabolite-to-parent compound ratios were calculated to estimate hydroxylase activity. Pairwise before vs after comparisons were made to evaluate effects of vitamin D2 and vitamin D3 on metabolism of vitamin D. Mean postsupplementation metabolite-to-parent ratios were then compared between groups. Results Vitamin D2 was less effective than vitamin D3 in elevating total serum 25(OH)D concentration. Vitamin D2 suppressed mean four-month serum concentrations of 25(OH)D3, 24R,25(OH)2D3, 1α,25(OH)2D3, and 4β,25(OH)2D3 and mean ratios of 25(OH)D3 to D3 and 1α,25(OH)2D3 to 25(OH)D3, while increasing the mean ratio of 24R,25(OH)2D3 to 25(OH)D3. Vitamin D3 increased mean four-month serum concentrations of 25(OH)D3, 24R,25(OH)2D3, 1α,25(OH)2D3, and 4β,25(OH)2D3 and the mean ratio of 24R,25(OH)2D3 to 25(OH)D3. Participants receiving vitamin D2 had lower mean postsupplementation ratios of 25(OH)D3 to vitamin D3 and 1α,25(OH)2D3 to 25(OH)D3 than those receiving vitamin D3. Mean postsupplementation ratios of 24R,25(OH)2D3 to 25(OH)D3 and 4β,25(OH)2D3 to 25(OH)D3 did not differ between groups. Conclusions Bolus-dose vitamin D2 is less effective than bolus-dose vitamin D3 in elevating total serum 25(OH)D concentration. Administration of vitamin D2 reduces 25-hydroxylation of vitamin D3 and 1-α hydroxylation of 25(OH)D3, while increasing 24R-hydroxylation of 25(OH)D3.

Effect of vitamin D3, 25-hydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 on parathyroid hormone secretion

1987 ◽  
Vol 41 (1) ◽  
pp. 48-51 ◽  
Author(s):  
Larry K. Cantley ◽  
John B. Russell ◽  
Deborah S. Lettieri ◽  
Louis M. Sherwood
Keyword(s):  
Parathyroid Hormone ◽  
Vitamin D3 ◽  
Hormone Secretion ◽  
Dihydroxyvitamin D3 ◽  
24,25 Dihydroxyvitamin D3

Effect of vitamin D3 metabolites on calcium and phosphorus metabolism in chick embryos

1985 ◽  
Vol 248 (3) ◽  
pp. E281-E285 ◽  
Author(s):  
L. E. Hart ◽  
H. F. DeLuca
Keyword(s):  
Vitamin D ◽  
Embryonic Development ◽  
Vitamin D3 ◽  
Chorioallantoic Membrane ◽  
Sole Source ◽  
Chick Embryos ◽  
Dihydroxyvitamin D3 ◽  
Total Body Calcium ◽  
1,25 Dihydroxyvitamin D3 ◽  
24,25 Dihydroxyvitamin D3

The biochemical nature of the physiological defect found in chick embryos from hens supported on 1,25-dihydroxyvitamin D3 as their sole source of vitamin D is described. Vitamin D-deficient hens (44-wk-old) were divided into six groups of five and dosed daily for 19 wk with either 2.0 micrograms of 25-hydroxyvitamin D3, 2.0 micrograms of 24,24-difluoro-25-hydroxy-vitamin D3, 0.4 micrograms of 1,25-dihydroxyvitamin D3, 2.0 micrograms of 24,25-dihydroxyvitamin D3, 0.4 micrograms of 1,25-dihydroxyvitamin D3 plus 2.0 micrograms of 24,25-dihydroxyvitamin D3, or vehicle only. Normal embryonic development was found in eggs from hens given 25-hydroxyvitamin D3 or 24,24-difluoro-25-hydroxyvitamin D3, whereas embryos from hens given 1,25-dihydroxyvitamin D3, 24,25-dihydroxyvitamin D3, or their combination were abnormal and failed to hatch. Embryos from hens fed 1,25-dihydroxyvitamin D3 and/or 24,25-dihydroxyvitamin D3 had vitamin D deficiency: low bone ash, low plasma calcium, low total body calcium, and extremely high plasma phosphorus. Because the shell is the major source of calcium for the developing embryo, calcium transport from the shell to the embryos across the chorioallantoic membrane apparently fails, giving rise to the observed defects in embryonic development.

Adaptation of vitamin D metabolism to calcium challenge: is it dependent on parathyroid hormone?

1989 ◽  
Vol 120 (3_Suppl) ◽  
pp. S122-S123
Author(s):  
S. H. SCHARLA ◽  
H. W. MINNE ◽  
U. G. LEMPERT ◽  
C. OSWALD ◽  
H. SCHMIDT-GAYK ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Vitamin D Metabolism

scholarly journals Metabolism and pharmacokinetics of 24,25-dihydroxyvitamin D3 in the vitamin D3-replete rat.

1985 ◽  
Vol 260 (25) ◽  
pp. 13625-13630
Author(s):  
K Jarnagin ◽  
S Y Zeng ◽  
M Phelps ◽  
H F DeLuca
Keyword(s):  
Vitamin D3 ◽  
Dihydroxyvitamin D3 ◽  
24,25 Dihydroxyvitamin D3

Metabolism of vitamin D in patients with primary biliary cirrhosis and alcoholic liver disease

1985 ◽  
Vol 69 (5) ◽  
pp. 561-570 ◽  
Author(s):  
E. Barbara Mawer ◽  
H. J. Klass ◽  
T. W. Warnes ◽  
Jacqueline L. Berry
Keyword(s):  
Vitamin D ◽  
Liver Disease ◽  
Primary Biliary Cirrhosis ◽  
Alcoholic Liver Disease ◽  
Vitamin D3 ◽  
Control Group ◽  
Biliary Cirrhosis ◽  
Vitamin D2 ◽  
Dihydroxyvitamin D3 ◽  
Poor Renal Function

1. The metabolism of isotopically labelled vitamin D2 and D3 has been investigated in eight patients with primary biliary cirrhosis and in five controls. The concentration of labelled vitamin D2 was lower than that of vitamin D3 in serum of patients with primary biliary cirrhosis on days 1 and 2 after intravenous injection (P < 0.005 and P < 0.05, respectively) but no difference was seen in controls. 2. Similar amounts of labelled 25-hydroxyvitamin D2 and D3 were seen in serum of the control group; the same pattern was observed in the primary biliary cirrhosis group, and no significant differences were observed between the two groups. 3. In both control and primary biliary cirrhosis groups, the serum concentration of labelled 24,25-dihydroxyvitamin D2 exceeded that of 24,25-dihydroxyvitamin D3 (significant for controls on day 2, P < 0.02) but concentrations in the two groups were not different. 4. Concentrations of labelled 25,26-dihydroxyvitamin D3 were significantly higher than those of 25,26-dihydroxyvitamin D2 in the primary biliary cirrhosis group at all times and in the control group on days 2 and 3. Both 25,26-dihydroxyvitamin D2 and D3 were higher in the serum of patients with primary biliary cirrhosis than in controls (significant on day 1, P < 0.05). 5. Urinary excretion over days 0–3 of radioactivity from both vitamins D2 and D3 was significantly higher in the primary biliary cirrhosis group than in controls: 12.03 vs 1.80% for vitamin D2 and 8.98 vs 1.76% for vitamin D3(P < 0.005). Vitamin D2-derived urinary radioactivity in primary biliary cirrhosis correlated strongly with serum bilirubin (P = 0.005). 6. The metabolism of labelled vitamin D3 was studied in seven patients with alcoholic liver disease, three of whom showed low serum concentrations of labelled 25-hydroxyvitamin D3 suggesting impaired hepatic synthesis. The 25-hydroxylation response was quantified as the relative index of 25-hydroxylation and was significantly related to two other indices of liver function. It is concluded that impaired 25-hydroxylation of vitamin D may occur in alcoholic liver disease and results from hepatocellular dysfunction. 7. Less than the predicted amounts of 1,25-dihydroxyvitamin D3 were produced in four of the seven patients with alcoholic liver disease; this defect may be attributable in part to decreased precursor 25-hydroxyvitamin D and to poor renal function.

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