Interrelationship among vitamin D metabolism, true calcium absorption, parathyroid function, and age in women: Evidence of an age-related intestinal resistance to 1,25-dihydroxyvitamin D action

2009 ◽  
Vol 6 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Richard Eastell ◽  
Alfred L. Yergey ◽  
Nancy E. Vieira ◽  
Sandra L. Cedel ◽  
Rajiv Kumar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Age Related ◽  
Parathyroid Function

Vitamin D and Calcitonin Treatment in Patients with Femoral Neck Fracture: A Prospective Controlled Clinical Study

1989 ◽  
Vol 17 (3) ◽  
pp. 226-242 ◽  
Author(s):  
E. Harju ◽  
R. Punnonen ◽  
R. Tuimala ◽  
J. Salmi ◽  
I. Paronen
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Serum Levels ◽  
Serum Calcitonin ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Age Related ◽  
Neck Fracture ◽  
25 Hydroxyvitamin D

The effects on general and bone metabolism of femoral neck fracture patients of 0.25 μg α-calcoid given orally twice daily ( n=9) and 25 μg calcitonin given subcutaneously 30 times ( n=10) in 10 weeks were studied against a control ( n=ll). Bone histology and histomorphometry showed non-age related osteoporosis in 30% and osteomalacia in 22% of the patients studied. Impaired serum vitamin D status was found in 47 – 88% of patients, secondary hyperparathyroidism and increased serum parathyroid hormone in 59% and decreased serum calcitonin levels in 69%. On histology, normal findings and non-age related osteoporosis on histology were associated with low serum levels of 25-hydroxyvitamin D3,1,25- and 24,25-dihydroxy vitamin D3. Very high serum levels of 1,25-dihydroxyvitamin D3 and low levels of 25-hydroxyvitamin D3 occurred in fracture patients with osteomalacia. Calcitonin improved calcium balance, reduced osteoporosis and increased the serum 1,25- and 24,25-dihydroxyvitamin D3 levels but had no effect on osteomalacia. Vitamin D reduced osteomalacia, slightly increased the serum 1,25-dihydroxyvitamin D3 concentration and decreased serum levels of parathyroid hormone. Both treatments gave a similar slight decrease in serum calcitonin concentrations. A mechanism of action for the treatments is suggested.

scholarly journals Combined Treatment with Omega-3 Fatty Acid and Cholecalciferol Increases 1,25-Dihydroxyvitamin D Levels by Modulating Dysregulation of Vitamin D Metabolism in 5/6 Nephrectomy Rats

Nutrients ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2903
Author(s):  
Su Mi Lee ◽  
Mi Hwa Lee ◽  
Young Ki Son ◽  
Seong Eun Kim ◽  
Won Suk An
Keyword(s):  
Vitamin D ◽  
Fatty Acid ◽  
Combined Treatment ◽  
Omega 3 ◽  
Sprague Dawley ◽  
Vitamin D Metabolism ◽  
Omega 3 Fatty Acid ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

The protein 1α-hydroxylase (CYP27B1) was expressed in liver and omega-3 fatty acid (FA) elevated 1,25-dihydroxyvitamin D [1,25(OH)2D] levels in dialysis patients. The aim of this study was to determine whether omega-3 FA and cholecalciferol have effects on vitamin D metabolism related to CYP27B1 and 24-hydroxylase (CYP24) activities in the kidney and liver of 5/6 nephrectomy (Nx) rats. Male Sprague–Dawley rats were divided into the following groups: sham control, 5/6 Nx, 5/6 Nx treated with cholecalciferol, 5/6 Nx treated with omega-3 FA, and 5/6 Nx treated with cholecalciferol/omega-3 FA. CYP27B1 and CYP24 expression were measured in the liver and kidney. Further, 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] levels were measured in serum. Among Nx groups, 1,25(OH)2D and 25(OH)D levels were lowest in the 5/6 Nx group. CYP24 expression was increased in the kidney of the 5/6 Nx rat model, which was found to be reversed by omega-3 FA or cholecalciferol/omega-3 FA supplementation. Decreased CYP27B1 expression was observed in the liver of the 5/6 Nx rats and its expression was recovered by supplementation with cholecalciferol/omega-3 FA. In conclusion, omega-3 FA and cholecalciferol may synergistically increase 1,25(OH)2D levels by inhibiting CYP24 expression in the kidney and liver and activating CYP27B1 expression in the liver of 5/6 Nx rats.

Effect of Parathyroid Hormone on Vitamin D Metabolism in Osteopetrosis

PEDIATRICS ◽  
1981 ◽  
Vol 68 (1) ◽  
pp. 109-112
Author(s):  
Dagfinn Aarskog ◽  
Lage Aksnes ◽  
Trond Markestad
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Serum Levels ◽  
Target Cells ◽  
Normal Range ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Basal Serum ◽  
Parathyroid Extract

Indices of vitamin D metabolism were studied before and after infusion of bovine parathyroid hormone extract in three children with osteopetrosis. Basal serum concentrations of calcium, alkaline phosphatase, and 25-hydroxyvitamin D tended to be low. Serum immunoreactive parathyroid hormone levels were in the upper normal range in two patients. A marked increase in urinary cyclic adenosine 3': 5'-monophosphate(cAMP) in all patients was solely due to an increase in the nephrogenous cAMP. The basal concentration of 1,25-dihydroxyvitamin D was clearly more than the upper limit of normal range in all three patients and increased after parathyroid extract infusion in one patient. The basal serum levels of 24,25-dihydroxyvitamin D were within normal limits and tended to decrease after parathyroid extract infusion in two of the patients. Parathyroid hormone and 1,25-dihydroxyvitamin D act in concert to increase calcium resorption from bone, and the increased serum levels of both these factors may reflect lack, or unresponsiveness, of target cells in bone.

Growth hormone increases serum 1,25-dihydroxyvitamin D levels and decreases 24,25-dihydroxyvitamin D levels in children with growth hormone deficiency

1997 ◽  
Vol 136 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Shi Wei ◽  
Hiroyuki Tanaka ◽  
Toshihide Kubo ◽  
Taeko Ono ◽  
Susumu Kanzaki ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Vitamin D ◽  
Renal Tubules ◽  
Vitamin D Metabolites ◽  
Gh Therapy ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Igf I ◽  
Phosphorus Levels

Abstract The influence of growth hormone (GH) on calcium–phosphorus metabolism and modulation of vitamin D metabolism has been demonstrated, but the mechanism remains unclear. We investigated the effect of a 6-month course of GH therapy on vitamin D and mineral metabolism in twelve GH-deficient children. Before GH therapy, levels of vitamin D metabolites and other biochemistry data were within normal ranges. All patients responded to GH therapy with increased growth velocity. 1,25-Dihydroxyvitamin D levels increased after 1 month of treatment and remained at these higher levels, with a significant increase found at 3 months (P < 0·05), whereas 24,25-dihydroxyvitamin D levels were decreased at 1 and 3 months, the latter being a significant decrease (P < 0·05), and then returned to the baseline levels at 6 months. 25-Hydroxyvitamin D levels did not change significantly. A significant increase in serum insulin-like growth factor-I (IGF-I) levels occurred during the 6 months of treatment (1 month, P < 0·01; 3 and 6 months, P < 0·001). Serum parathyroid hormone (PTH) levels decreased significantly at 3 and 6 months (3 months, P < 0·01; 6 months, P < 0·05). Serum calcium and phosphorus levels did not change significantly. Significant increases were found in the urinary calcium/urinary creatinine ratio (3 and 6 months, P < 0·05) and the percent tubular reabsorption of phosphorus levels (1 and 3 months, P 0·05). The results of this study confirmed the actions of GH on renal tubules with increases in calcium excretion and phosphorus reabsorption, and indicate that the action of GH on modulating vitamin D metabolism may be IGF-I mediated, not PTH mediated. European Journal of Endocrinology 136 45–51

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