Adaptation to dietary calcium and phosphorus restriction changes with age in the rat

1980 ◽  
Vol 239 (5) ◽  
pp. E322-E327 ◽  
Author(s):  
H. J. Armbrecht ◽  
T. V. Zenser ◽  
C. J. Gross ◽  
B. B. Davis
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Active Transport ◽  
Intestinal Adaptation ◽  
Tubular Reabsorption ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Calcium And Phosphorus ◽  
F344 Rats ◽  
Male F344 Rats

The purpose of this study was to characterize the changes that take place in adaptation to chronic calcium (Ca) or phosphorus (P) restriction with age. Adaptation in male F344 rats aged 1.5, 3, 12, and 18 mo was studied by feeding rats either a low-Ca diet, a low-P diet, or a high-Ca-P diet for 14 days. Plasma Ca remained relatively constant with age, but plasma P markedly decreased between 3 and 12 mo regardless of diet. Intestinal adaptation was determined by measuring the active transport of Ca by the intestine and by measuring the production of vitamin D-dependent calcium-binder protein. There was significant intestinal adaptation to Ca or P restriction at 1.5 mo, but there was none thereafter because Ca transport declined rapidly with age regardless of diet. The kidney adapted to the low-P diet by significantly reducing P excretion at all ages. In rats on a low-P diet, there was an increase in urinary P, which was due to a decrease in the tubular reabsorption of P and a decrease in urinary Ca with age. These changes in adaptation may reflect a decrease in serum 1,25-dihydroxyvitamin D levels and an increase in parathyroid hormone levels with age.

scholarly journals Vitamin D Status among Thai School Children and the Association with 1,25-Dihydroxyvitamin D and Parathyroid Hormone Levels

PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e104825 ◽  
Author(s):  
Lisa A. Houghton ◽  
Andrew R. Gray ◽  
Michelle J. Harper ◽  
Pattanee Winichagoon ◽  
Tippawan Pongcharoen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
School Children ◽  
Vitamin D Status ◽  
Hormone Levels ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs

1987 ◽  
Vol 65 (8) ◽  
pp. 2111-2112 ◽  
Author(s):  
Ajai K. Srivastav ◽  
L. Rani ◽  
K. Swarup
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Vitamin D Analogs ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Rana Tigrina ◽  
Calcium Deposits ◽  
25 Hydroxyvitamin D ◽  
Calcium And Phosphorus

Intraperitoneal injections of either vitamin D3 (4 IU/100 g body wt.), 25 hydroxyvitamin D3 (100 ng/100 g body wt.), or 1,25 dihydroxyvitamin D3 (100 ng/100 g body wt.) for 15 days induced hypercalcemia, hyperphosphatemia, and depletion of calcium deposits in the paravertebral lime sacs in an anuran, Rana tigrina.

scholarly journals Vitamin D status: effects on parathyroid hormone and 1,25-dihydroxyvitamin D in postmenopausal women

2000 ◽  
Vol 71 (6) ◽  
pp. 1577-1581 ◽  
Author(s):  
Allan G Need ◽  
Michael Horowitz ◽  
Howard A Morris ◽  
BE Christopher Nordin
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Postmenopausal Women ◽  
Vitamin D Status ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

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 IDIOPATHIC INFANTILE HYPERCALCEMIA . DESCRIPTION OF CLINICAL CASES AND REVIEW.

2017 ◽  
Vol 63 (1) ◽  
pp. 51-57
Author(s):  
Yulia V. Tikhonovich ◽  
Anna A. Kolodkina ◽  
Kristina S. Kulikova ◽  
Yulia Yu. Golubkina ◽  
Natalia Yu. Kalinchenko ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Family Counseling ◽  
Compound Heterozygous ◽  
Loss Of Function ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Low Calcium Diet ◽  
Idiopathic Infantile Hypercalcemia ◽  
Vitamin D Supplements

Vitamin D plays a central role in calcium homeostasis. Impaired degradation  of 1,25-dihydroxyvitamin D due to loss-of-function mutations in CYP24A1 leads to significant hypercalcemia, hypercalciuria,  suppressed level of parathyroid hormone (PTH),  nephrocalcinosis and nephrolithiasis.  This condition has been called Idiopathic infantile hypercalcemia. Treatment includes low calcium diet, rehydration, furosemid,  avoidance of vitamin D supplements  and sun protection.   In severe  cases   glucocorticoids, ketoconazole,  bisphosphonates  and  hemodiafiltration may be used. Early diagnosis of the disease allows to develop an individual plan for managing these patients to prevent the formation of kidney disease, to conduct a genetic family counseling. Here, we describe the cohort of  patients (3  children, 2 adults)  with significant hypercalcemia due to  homo- and compound heterozygous mutations in CYP24A1, describe  the main clinical and laboratory characteristics, diagnosis, principles and foundations of the management of patients with this pathology.

Effect of Parathyroid Hormone on cAMP and 1,25-Dihydroxyvitamin D Formation and Renal Handling of Phosphate in Vitamin D-Dependent Rickets

PEDIATRICS ◽  
1983 ◽  
Vol 71 (1) ◽  
pp. 59-63
Author(s):  
Dagfinn Aarskog ◽  
Lage Aksnes ◽  
Trond Markestad
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Serum Concentration ◽  
Urinary Excretion ◽  
Serum Levels ◽  
Renal Handling ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Control Subjects

Studies were carried out to compare the effects of parathyroid extract (PTE) on the serum concentration of 1,25-dihydroxyvitamin D (1,25[OH]2D), 24,25-dihydroxyvitamin D (24,25[OH]2D), 25,26-dihydroxy vitamin D (25,26[OH]2D) and cAMP, and the urinary excretion of calcium, phosphorus, and cAMP in two normal adult subjects, and in a girl with vitamin D-dependent rickets. The concentration of 1,25[OH]2D was markedly decreased even when she was receiving a daily dose of 25,000 IU of ergocalciferol. PTE infusion resulted in a prompt and distinct increase in the serum levels and the urinary excretion of cAMP in the patient and control subjects. In the control subjects the serum concentration of 1,25[OH]2D increased after the PTE infusion, whereas there was no response in the patient with vitamin D-dependent rickets. The two other dihydroxylated metabolites of vitamin D showed no consistent response to the PTE infusion in the control subjects or the patient. The patient showed no phosphaturic response to PTE while she was receiving high-dosage ergocalciferol treatment. By contrast, when the patient was re-studied after therapy with lα-hydroxyvitamin D, PTE infusion resulted in an increase in urinary phosphate excretion. These findings might lend support for the notion that 1,25[OH]2D has an effect on tubular phosphate resorption and has a permissive role in the phosphaturic effect of parathyroid hormone. The present findings also confirm that the formation of 1,25[OH]2D is impaired in vitamin D-dependent rickets and indicate that the renal 25-hydroxyvitamin D-lα-hydroxylase is unresponsive to the stimulatory effect of parathyroid hormone in this condition.

1,25-Dihydroxyvitamin D increases the gene expression of enzymes protecting from glucolipotoxicity in peripheral blood mononuclear cells and human primary endothelial cells

2016 ◽  
Vol 7 (6) ◽  
pp. 2537-2543 ◽  
Author(s):  
Katarina Kuricova ◽  
Anna Pleskacova ◽  
Lukas Pacal ◽  
Katerina Kankova
Keyword(s):  
Gene Expression ◽  
Vitamin D ◽  
Endothelial Cells ◽  
Mononuclear Cells ◽  
Peripheral Blood Mononuclear ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Blood Mononuclear Cells ◽  
Classical Function ◽  
Calcium And Phosphorus

Besides its classical function as an orchestrator of calcium and phosphorus homeostasis, vitamin D also affects insulin secretion and tissue efficiency.

scholarly journals Diurnal rhythm of plasma 1,25-dihydroxyvitamin D and vitamin D-binding protein in postmenopausal women: relationship to plasma parathyroid hormone and calcium and phosphate metabolism

2002 ◽  
pp. 635-642 ◽  
Author(s):  
L Rejnmark ◽  
AL Lauridsen ◽  
P Vestergaard ◽  
L Heickendorff ◽  
F Andreasen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Postmenopausal Women ◽  
Diurnal Rhythm ◽  
Plasma Levels ◽  
Diurnal Variations ◽  
Vitamin D Binding Protein ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Pattern Of Variation

OBJECTIVE: Diurnal variations in plasma levels of 1,25-dihydroxyvitamin D (1,25(OH)(2)D) have previously only been investigated in young individuals, and these studies have failed to demonstrate a diurnal rhythm. We have studied whether plasma levels of 1,25(OH)(2)D and vitamin D-binding protein (DBP) vary in a diurnal rhythm in postmenopausal women. METHODS: Blood and urine were sampled with 2- and 4-h intervals in order to assess diurnal variations in plasma levels of 1,25(OH)(2)D, DBP and parathyroid hormone (PTH), as well as in plasma levels and urinary excretion rates of calcium and phosphate. Additionally, the free 1,25(OH)(2)D index was calculated (the molar ratio of 1,25(OH)(2)D to DBP). RESULTS: Plasma 1,25(OH)(2)D exhibited a diurnal rhythm (P<0.01) with a nadir in the morning (99+/-12 pmol/l), followed by a rapid increase to a plateau during the day (113+/-13 pmol/l, i.e. 14% above nadir level; P=0.005). A similar pattern of variation was found in plasma levels of DBP with peak levels 15% above nadir levels (P<0.01). The free 1,25(OH)(2)D index did not vary in a diurnal rhythm. PTH and plasma levels and urinary excretions of calcium and phosphate exhibited a diurnal pattern of variation. The diurnal rhythm of DBP was correlated with the rhythm of 1,25(OH)(2)D (r=0.47, P<0.01) and plasma albumin (r=0.76, P<0.01). Moreover, the rhythm of plasma calcium and PTH varied inversely (r=-0.36, P=0.02). CONCLUSIONS: With the disclosure of a diurnal rhythm of total plasma 1,25(OH)(2)D, all major hormones and minerals related to calcium homeostasis have now been shown to exhibit diurnal variations. In clinical studies, the diurnal variations of 1,25(OH)(2)D and DBP must be considered, i.e. blood sampling must be standardised according to the time of day.

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.

Hypercalciuric Hypophosphatemic Rickets, Mineral Balance, Bone Histomorphometry, and Therapeutic Implications of Hypercalciuria

PEDIATRICS ◽  
1989 ◽  
Vol 84 (2) ◽  
pp. 276-280
Author(s):  
C. Chen ◽  
T. Carpenter ◽  
N. Steg ◽  
R. Baron ◽  
C. Anast
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Hypophosphatemic Rickets ◽  
Balance Study ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Study Results ◽  
Calcium And Phosphorus

A 14-year-old Turkish boy had severe rickets that had been clinically evident since he was 2 years of age. When he was 5 years of age, he had normal serum calcium and phosphorus levels and increased alkaline phosphatase activity. Treatment with modest dosages of vitamin D (5000 U/d for 3 weeks) resulted in hypercalcemia. At 10 years of age, high-dose vitamin D (40 000 U/d) plus phosphorus (1.1 g/d) therapy for 20 days resulted in symptomatic nephrolithiasis. When, 14 years of age, he had normocalcemia, hypophosphatemia, increased alkaline phosphatase activity, and normal circulating parathyroid hormone concentration. Levels of 25-hydroxyvitamin D were normal but those of 1,25-dihydroxyvitamin D were markedly increased. Rickets and osteopenia were evident on radiographs, and osteomalacia was present on trabecular bone obtained at biopsy. Balance study results showed increased intestinal absorption of calcium and phosphorus, hypercalciuria, and increased urinary phosphorus excretion. This patient manifests an unusual form of hypophosphatemic rickets in which hypercalciuria is a cardinal feature. In contrast with most varieties of hypophosphatemia, this disorder is characterized by appropriately increased production of 1,25-dihydroxyvitamin D in response to hypophosphatemia. It is recommended that urinary calcium excretion be assessed in all patients with hypophosphatemic rickets so that appropriate therapy will be instituted.

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