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.

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

scholarly journals Plasma 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and parathyroid hormone in familial hypocalciuric hypercalcemia and primary hyperparathyroidism

2008 ◽  
Vol 159 (6) ◽  
pp. 719-727 ◽  
Author(s):  
Signe Engkjær Christensen ◽  
Peter H Nissen ◽  
Peter Vestergaard ◽  
Lene Heickendorff ◽  
Lars Rejnmark ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Plasma Levels ◽  
Familial Hypocalciuric Hypercalcemia ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D

IntroductionFamilial hypocalciuric hypercalcemia (FHH) is a lifelong, benign, inherited condition caused by inactivating mutations in the calcium-sensing receptor (CASR) gene. Both FHH and primary hyperparathyroidism (PHPT) are characterized by elevated P-calcium, normal or elevated plasma-parathyroid hormone (P-PTH), and typically normal renal function. In PHPT, vitamin D metabolism is typically characterized by low plasma levels of 25-hydroxyvitamin D (25OHD), and high plasma levels of 1,25-dihydroxyvitamin D (1,25(OH)2D). In FHH, the vitamin D metabolism is not very well known.ObjectiveTo compare and evaluate plasma 25OHD, 1,25(OH)2D, and PTH in FHH and PHPT.DesignCross-sectional study.MaterialsAbout 66 FHH patients with mutations in the CASR gene, 147 patients with surgically verified PHPT, and 46 controls matched to FHH patients according to age (±5 years), sex, and season. All patients had a P-creatinine <140 μmol/l.MethodsWe measured P-calcium, P-Ca2+, P-albumin, P-creatinine, P-phosphate, P-magnesium, and P-PTH by standard laboratory methods. P-25OHD and P-1,25(OH)2D were measured by RIA or enzyme immunoassay. In FHH, all protein-coding exons in the CASR gene were sequenced and aligned to GenBank reference sequence .ResultsPHPT patients had higher body mass index (2p<0.01), together with higher P-PTH (2p<0.01) and P-1,25(OH)2D (2p<0.01) compared with FHH patients. The groups had similar levels of P-Ca2+ and of P-25OHD. The phenotypic expression of the CASR mutations (as determined by the degree of hypercalcemia) did not influence the levels of P-1,25(OH)2D.ConclusionEven though P-calcium and P-25OHD were comparable, P-1,25(OH)2D and P-PTH differed between FHH and PHPT.

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

scholarly journals Regulation of 1,25-Dihydroxyvitamin D Synthesis by Intracellular Vitamin D Binding Protein-1

Endocrinology ◽  
2002 ◽  
Vol 143 (10) ◽  
pp. 4135-4135 ◽  
Author(s):  
Shaoxing Wu ◽  
Rene Chun ◽  
Mercedes A. Gacad ◽  
Songyang Ren ◽  
Hong Chen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Vitamin D Binding Protein ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

1,25-Dihydroxyvitamin D and Vitamin D-Binding Protein Are Both Decreased in Streptozotocin-Diabetic Rats*

Endocrinology ◽  
1985 ◽  
Vol 116 (6) ◽  
pp. 2483-2488 ◽  
Author(s):  
BULANGU L. NYOMBA ◽  
ROGER BOUILLON ◽  
WILLY LISSENS ◽  
HUGO VAN BAELEN ◽  
PIETER DE MOOR
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Diabetic Rats ◽  
Vitamin D Binding Protein ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Streptozotocin Diabetic Rats

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.

Early effects of ethinyloestradiol and norethisterone treatment in post-menopausal women on bone resorption and calcium regulating hormones

1985 ◽  
Vol 69 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Peter L. Selby ◽  
Munro Peacock ◽  
Stuart A. Barkworth ◽  
Wendy B. Brown ◽  
Geoffrey A. Taylor
Keyword(s):  
Bone Resorption ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
Vitamin D Binding Protein ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Menopausal Women ◽  
Early Effects ◽  
Post Menopausal ◽  
Free Plasma

1. The early effects of sex steroid therapy were assessed in 28 normal post-menopausal women, 18 treated with ethinyloestradiol and 10 with norethisterone. 2. There was a reduction in the fasting urinary excretion of both calcium and hydroxyproline with both treatments, indicating reduced bone resorption. This was apparent after 1 week of therapy but became more marked after 3 weeks. 3. These changes were not accompanied by any changes in plasma levels of calcitonin or parathyroid hormone. 4. Patients receiving ethinyloestradiol showed a marked increase in plasma 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentration but this was explicable entirely in terms of increased plasma levels of vitamin D binding protein. There was no change in the free plasma level of 1,25(OH)2D. Patients treated with norethisterone showed no increase in plasma concentrations of 1,25(OH)2D. 5. We conclude that both ethinyloestradiol and norethisterone have a rapid and similar effect in reducing bone resorption. This is not mediated via the plasma levels of the calcium regulating hormones.

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.

Perinatal parathyroid hormone, vitamin D metabolites, and calcitonin in man

1980 ◽  
Vol 239 (5) ◽  
pp. E385-E390 ◽  
Author(s):  
P. Wieland ◽  
J. A. Fischer ◽  
U. Trechsel ◽  
H. R. Roth ◽  
K. Vetter ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Plasma Levels ◽  
Maternal Blood ◽  
Sign Test ◽  
Blood Levels ◽  
Vitamin D Metabolites ◽  
Dihydroxyvitamin D ◽  
Umbilical Blood ◽  
Arteriovenous Difference

Plasma levels of calcium and of parathyroid hormone (PTH) were comparable in the mothers at delivery and in nonpregnant controls; magnesium was decreased (P < 0.001) in maternal blood; and phosphate (P < 0.001), 1,25-dihydroxyvitamin D (1,25(OH)2D) (P < 0.001), and calcitonin (CT) (P < 0.01) were raised. Cord levels of calcium (P < 0.01), magnesium (P < 0.05), and CT (P < 0.01) were higher, and PTH (P < 0.01) was lower than in the maternal blood. Levels of 25(OH)D, 1,25(OH)2D, and 24,25(OH)2D lower in fetal than in maternal blood (P < 0.01) and significant linear correlations between the vitamin D metabolites examined in mothers and neonates (P < 0.001) are consistent with a diffusion barrier across the placenta and/or different affinities of binding proteins. Plasma levels of 25(OH)D and 24,25(OH)2D were significantly related (P < 0.01), suggesting precursor product type, relationships. Levels of 1,25(OH)2D higher in arterial than in venous umbilical blood (P = 0.06, sign test; P < 0.005, paired t test) suggest that the fetus participates in the synthesis of 1,25(OH)2D. Maternal PTH was significantly related to the arteriovenous difference of 1,25(OH)2D levels (P < 0.01) in cord blood, and it possibly enhances the synthesis of 1,25(OH)2D during the final stage of fetal development.

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