scholarly journals Vitamin D Metabolites Affect Serum Calcium and Phosphate in Freshwater Catfish, Heteropneustes fossilis

1997 ◽  
Vol 14 (5) ◽  
pp. 743-746 ◽  
Author(s):  
Ajai K. Srivastav ◽  
Sunil K. Srivastav ◽  
Yuichi Sasayama ◽  
Nobuo Suzuki ◽  
Anthony W. Norman
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Vitamin D Metabolites ◽  
Heteropneustes Fossilis ◽  
Freshwater Catfish

Effect of Various Vitamin D Metabolites on Serum Calcium and Inorganic Phosphate in the Freshwater Snake Natrix piscator

1995 ◽  
Vol 100 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Ajai K. Srivastav ◽  
Sunil K. Srivastav ◽  
Sarita Singh ◽  
Anthony W. Norman
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Inorganic Phosphate ◽  
Vitamin D Metabolites

scholarly journals Vitamin D Metabolism Is Significantly Impaired in COVID-19 Inpatients

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A281-A282
Author(s):  
Alexandra Povaliaeva ◽  
Liudmila Ya Rozhinskaya ◽  
Ekaterina A Pigarova ◽  
Larisa K Dzeranova ◽  
Nino N Katamadze ◽  
...  
Keyword(s):  
Vitamin D ◽  
Secondary Hyperparathyroidism ◽  
Vitamin D Deficiency ◽  
Serum Calcium ◽  
Vitamin D Supplementation ◽  
Vitamin D Metabolites ◽  
Lung Involvement ◽  
Hydroxylase Activity ◽  
Vitamin D Metabolism ◽  
Vitamin D Levels

Abstract Objective: to assess the state of vitamin D metabolism in patients hospitalized with COVID-19 infection. Materials and methods: We examined 49 patients, which were hospitalized for inpatient treatment of COVID-19 infection from May to June 2020. Study group included 24 men (49%) and 25 women (51%), median age 58 years [48; 70], BMI 26.4 kg/m2 [24.3; 30.5]. All patients were diagnosed with pneumonia due to SARS-CoV-2 with median percent of lung involvement equal to 29% [14; 37], 22 patients (45%) required oxygen support upon admission. Median SpO2 was equal to 95% (92; 97), median NEWS score was equal to 3 [2; 6]. Participants were tested for vitamin D metabolites (25(OH)D3, 1,25(OH)2D3, 3-epi-25(OH)D3, 24,25(OH)2D3 and D3) by UPLC-MS/MS, free 25(OH)D and vitamin D-binding protein by ELISA, as well as PTH by electrochemiluminescence immunoassay and routine biochemical parameters of blood serum (calcium, phosphorus, albumin) at the time of admission. Results: patients had in general very low 25()D3 levels - median 10.9 ng/mL [6.9; 15.6], corresponding to a pronounced vitamin D deficiency in half of the patients. Levels of 24,25(OH)2D3 were also low – 0.5 ng/mL [0.2; 0.9], and resulting vitamin D metabolite ratios (25(OH)D3/24,25(OH)2D3) were high-normal or elevated in most patients – 24.1 [19.0; 39.2], indicating decreased activity of 24-hydroxylase. Levels of 1,25(OH)2D3, on the contrary, were high-normal or elevated - 57 pg/mL [46; 79], which, in accordance with 25(OH)D3/1,25(OH)2D3 ratio (219 [134; 266]) suggests an increase in 1α-hydroxylase activity. Median level of 3-epi-25(OH)D3 was 0.7 ng/mL [0.4; 1.0] and D3 metabolite was detectable only in 6 patients. Median DBP level was 432 mg/L [382; 498], median free 25(OH)D was 5.6 pg/mL [3.3; 6.7], median calculated free 25(OH)D was 2.0 pg/mL [1.4; 3.3]. Most patients had albumin-adjusted serum calcium level in the lower half of reference range (median 2.24 mmol/L [2.14; 2.34]). Seven patients had secondary hyperparathyroidism and one patient had primary hyperparathyroidism, the rest of the patients had PTH levels within the normal range.25(OH)D3 levels showed significant negative correlation with percent of lung involvement (r = -0.36, p<0.05) and positive correlation with SpO2 (r = 0.4, p<0.05). 1,25(OH)2D3 levels correlated positively with 25(OH)D3 levels (r = 0.38, p<0.05) and did not correlate significantly with PTH levels (p>0.05). Conclusion: Our data suggests that hospitalized patients with COVID-19 infection have significant impairment of vitamin D metabolism, in particular, an increase in 1α-hydroxylase activity, which cannot be fully explained by pre-existing conditions such as vitamin D deficiency and secondary hyperparathyroidism. The observed profound vitamin D deficiency and association of vitamin D levels with markers of disease severity indicate the importance of vitamin D supplementation in these patients.

Vitamin D Metabolism in Patients Intoxicated with Ergocalciferol

1985 ◽  
Vol 68 (2) ◽  
pp. 135-141 ◽  
Author(s):  
E. Barbara Mawer ◽  
J. T. Hann ◽  
Jacqueline L. Berry ◽  
M. Davies
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Mass Action ◽  
Vitamin D Metabolites ◽  
Serum Concentrations ◽  
High Concentration ◽  
Vitamin D Metabolism ◽  
Serum Calcium Concentration ◽  
Per Se

1. Vitamin D metabolites were measured on admission in eight patients intoxicated with ergocalciferol (serum calcium 3.01-4.05 mmol/l) and also during the subsequent 2 months in six of the eight. 2. Serum concentrations of 25-hydroxyergocalciferol, on admission, were grossly elevated in all patients (range 583-1843 nmol/l). 3. Serum calcium concentration was related significantly only to the concentration of 25-hydroxyergocalciferol (P = 0.003). 4. Concentrations of 25-hydroxyergocalciferol in serum were significantly related to those of calciferol (P = 0.004). 5. Elevated initial concentrations of 1,25-dihydroxycalciferol, mainly as 1,25-dihydroxyergocalciferol, were found in seven of the eight patients (range 179-313 pmol/l). 6. It is suggested that the hypercalcaemia in these patients may be explained by the action of 25-hydroxyergocalciferol at high concentration in competing for 1,25-dihydroxycalciferol receptors, thus exerting a biological effect per se, and also by increasing the synthesis of 1,25-dihydroxycalciferol through a mass-action effect on the renal 1α-hydroxylase.

Effects of deltamethrin on serum calcium and corpuscles of Stannius of freshwater catfish,Heteropneustes fossilis

2009 ◽  
Vol 91 (4) ◽  
pp. 761-772 ◽  
Author(s):  
A.K. Srivastav ◽  
S.K. Srivastava ◽  
D. Mishra ◽  
S.K. Srivastav ◽  
N. Suzuki
Keyword(s):  
Serum Calcium ◽  
Heteropneustes Fossilis ◽  
Corpuscles Of Stannius ◽  
Freshwater Catfish

Renal osteodystrophy

2013 ◽  
Author(s):  
Thomas Bardin ◽  
Tilman Drüeke
Keyword(s):  
Vitamin D ◽  
Bone Turnover ◽  
Serum Calcium ◽  
Renal Osteodystrophy ◽  
Serum Phosphorus ◽  
Osteitis Fibrosa ◽  
Phosphate Binders ◽  
Type I ◽  
Vitamin D Metabolites ◽  
Alkaline Phosphatases

Renal osteodystrophy (ROD) is a term that encompasses the various consequences of chronic kidney disease (CKD) for the bone. It has been divided into several entities based on bone histomorphometry observations. ROD is accompanied by several abnormalities of mineral metabolism: abnormal levels of serum calcium, phosphorus, parathyroid hormone (PTH), vitamin D metabolites, alkaline phosphatases, fibroblast growth factor-23 (FGF-23) and klotho, which all have been identified as cardiovascular risk factors in patients with CKD. ROD can presently be schematically divided into three main types by histology: (1) osteitis fibrosa as the bony expression of secondary hyperparathyroidism (sHP), which is a high bone turnover disease developing early in CKD; (2) adynamic bone disease (ABD), the most frequent type of ROD in dialysis patients, which is at present most often observed in the absence of aluminium intoxication and develops mainly as a result of excessive PTH suppression; and (3) mixed ROD, a combination of osteitis fibrosa and osteomalacia whose prevalence has decreased in the last decade. Laboratory features include increased serum levels of PTH and bone turnover markers such as total and bone alkaline phosphatases, osteocalcin, and several products of type I collagen metabolism products. Serum phosphorus is increased only in CKD stages 4-5. Serum calcium levels are variable. They may be low initially, but hypercalcaemia develops in case of severe sHP. Serum 25-OH-vitamin D (25OHD) levels are generally below 30 ng/mL, indicating vitamin D insufficiency or deficiency. The international KDIGO guideline recommends serum PTH levels to be maintained in the range of approximately 2-9 times the upper normal normal limit of the assay and to intervene only in case of significant changes in PTH levels. It is generally recommended that calcium intake should be up to 2 g per day including intake with food and administration of calcium supplements or calcium-containing phosphate binders. Reduction of serum phosphorus towards the normal range in patients with endstage kidney failure is a major objective. Once sHP has developed, active vitamin D derivatives such as alfacalcidol or calcitriol are indicated in order to halt its progression.

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