Vitamin D3 metabolism in a pig strain with pseudo vitamin D-deficiency rickets, type I

1987 ◽  
Vol 115 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Reinhard Kaune ◽  
Johein Harmeyer
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Type I ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Before And After ◽  
25 Hydroxyvitamin D ◽  
Deficiency Rickets ◽  
Clinical Healing

Abstract. Vitamin D metabolism was studied in the 'Hannover Pig', a strain which suffers from pseudo vitamin D-deficiency rickets, type I. Animals of this strain are known to be devoid of renal 25-hydroxyvitamin D3-1α-hydroxylase and -24-hydroxylase activities. Pigs with florid rickets and hypocalcaemia were treated with single im injections of 0.25 to 1.25 mg of vitamin D3, doses that have been shown in previous studies to be effective in producing transient healing of rachitic symptoms. The levels of vitamin D3 and its most relevant physiological metabolites in plasma were estimated at intervals before and after this vitamin D3 treatment. Vitamin D3 rose from 14.8 ± 8.1 to 364 ± 190 nmol/l (mean ± sd) 2 to 3 days post injectionem, 25-hydroxyvitamin D3 from 131.0 ± 46.2 to 1068 ± 160 nmol/l within 7 days post injectionem. The 1α,25-dihydroxyvitamin D3 concentration in plasma was elevated from 73.9 ± 25.0 to 281 ± 168 pmol/l 2 to 3 days post injectionem and declined continually from that time. 24R,25-dihydroxyvitamin D3 and 25S,26-dihydroxyvitamin D3 levels after treatment showed different responses in different animals being either elevated or unchanged. Clinical healing of the pigs with these doses of vitamin D3 was attributed to the transient rise of 1α,25-dihydroxyvitamin D3 in plasma. It was assumed that 1α,25-dihydroxyvitamin D3 synthesis takes place under these circumstances in extrarenal tissues.

VITAMIN D SUPPLEMENTATION IN FEMALE NURSES: THE EFFECTS ON SERUM 25-HYDROXYVITAMIN D, AND NON-SPECIFIC MUSCULOSKELETAL PAIN

2015 ◽  
Vol 18 (02) ◽  
pp. 1550008 ◽  
Author(s):  
Negin Masoudi Alavi ◽  
Mahla Madani ◽  
Mohsen Taghizadeh ◽  
Mohammad Reza Sharif
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Musculoskeletal Pain ◽  
Vitamin D Supplementation ◽  
High Dose ◽  
Single High Dose ◽  
Hydroxyvitamin D ◽  
Before And After ◽  
25 Hydroxyvitamin D ◽  
Female Nurses

Purpose: To investigate the effect of weekly single high dose vitamin D supplementation on serum 25-hydroxyvitamin D [25(OH)D], and non-specific musculoskeletal pain in female nurses. Methods: In this prospective study in Kashan/Iran, from April 1, 2014, through September 30, 2014, the 150 nurses with vitamin D deficiency received the weekly pearls of 50,000 units of vitamin D3 for 10 weeks. The serum level of 25(OH)D was measured before and after supplement therapy. The subjects were also asked to complete the Extended Nordic Musculoskeletal Questionnaire. All analyses were conducted with SPSS version 16. Results: After 10 weeks of intervention there was [Formula: see text][Formula: see text]ng/mL increase in 25(OH)D. The 82 nurses (54.7%) had 25(OH)D in normal range, while the 68 nurses (45.3%) were still vitamin D deficient. Weight could explain 15.4% increase in 25(OH)D. Before intervention 135 (90%), of nurses reported musculoskeletal pain in at least one region, after intervention this number decreased to 72.7%. There was a statistically significant improvement in musculoskeletal pain in neck, shoulders, upper back, lower back, hips/tights, knees, and ankles/feet after intervention. Conclusions: The weekly single high dose of vitamin D for 10 weeks could resolve vitamin D deficiency in about half of the patients. Patients with non-specific musculoskeletal pain might benefit from vitamin D supplementation.

Dr. Arnaud Replies

PEDIATRICS ◽  
1977 ◽  
Vol 60 (5) ◽  
pp. 761-761
Author(s):  
Sara B. Arnaud
Keyword(s):  
Vitamin D ◽  
Statistical Analysis ◽  
Vitamin D Deficiency ◽  
Statistical Comparison ◽  
Hydroxyvitamin D ◽  
Number Of Patients ◽  
25 Hydroxyvitamin D ◽  
Deficiency Rickets ◽  
Student’S T ◽  
Student’S T Test

Drs. Giangiacomo and Gleason are quite correct in their criticism that the number of patients with vitamin D deficiency rickets is too small for statistical comparison of the concentration of serum 25-hydroxyvitamin D (25-OH-D) in mild, moderate, and severe rickets. For this reason, we did not attempt this type of statistical comparison (Student's t test). The statistical analysis which supports our conclusion is the calculation of the regression between senim 25-OH-D, ng/ml and the stage of the disease, designated by arbitrary numbers 1, 2, and 3 for mild, moderate, and severe.

Metabolic inactivation of vitamin D is enhanced in primary hyperparathyroidism

1987 ◽  
Vol 73 (6) ◽  
pp. 659-664 ◽  
Author(s):  
M. R. Clements ◽  
M. Davies ◽  
D. R. Fraser ◽  
G. A. Lumb ◽  
E. Barbara Mawer ◽  
...  
Keyword(s):  
Vitamin D ◽  
Primary Hyperparathyroidism ◽  
Parathyroid Adenoma ◽  
Vitamin D Deficiency ◽  
Metabolic Clearance ◽  
Half Time ◽  
Hydroxyvitamin D ◽  
Elimination Half ◽  
Before And After ◽  
25 Hydroxyvitamin D

1. The elimination half-time of 25-hydroxyvitamin D in plasma was estimated after intravenous injection of the radioactively labelled metabolite in seven patients with primary hyperparathyroidism before and after excision of a parathyroid adenoma. 2. The elimination half-time of 25-hydroxyvitamin D was significantly shortened in primary hyperparathyroidism and reverted towards normal after parathyroidectomy. 3. The increased metabolic clearance of 25-hydroxyvitamin D in primary hyperparathyroidism was accounted for by an increased excretion of vitamin D-derived inactivation products in the faeces. 4. Enhanced hepatic inactivation of 25-hydroxyvitamin D may be important in the development of vitamin D deficiency in primary hyperparathyroidism.

scholarly journals Vitamin D3 metabolite ratio as an indicator of vitamin D status and its association with diabetes complications

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Lina H. M. Ahmed ◽  
Alexandra E. Butler ◽  
Soha R. Dargham ◽  
Aishah Latif ◽  
Omar M. Chidiac ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Diabetic Complications ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Metabolite Ratio ◽  
25 Hydroxyvitamin D ◽  
Artery Disease

Abstract Background Vitamin D deficiency is diagnosed by total serum 25-hydroxyvitamin D (25(OH)D) concentration and is associated with poor health and increased mortality; however, some populations have low 25(OH) D concentrations without manifestations of vitamin D deficiency. The Vitamin D Metabolite Ratio (VMR) has been suggested as a superior indicator of vitamin D status. Therefore, VMR was determined in a population with type 2 diabetes at high risk for vitamin D deficiency and correlated with diabetic complications. Research design and methods Four hundred sisty patients with type 2 diabetes (T2D) were recruited, all were vitamin D3 supplement naive. Plasma concentration of 25-hydroxyvitamin D3 (25(OH)D3) and its metabolites 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) and its epimer, 3-epi-25-hydroxyvitamin D3 (3-epi-25(OH)D3), were measured by LC-MS/MS analysis. VMR-1 was calculated as a ratio of 24,25(OH)2D3:25(OH)D3; VMR-2 as a ratio of 1,25(OH)2D3:25(OH)D3; VMR-3 was calculated as a ratio of 3-epi-25(OH)D3: 25(OH)D3. Results An association means that there were significant differences between the ratios found for those with versus those without the various diabetic complications studied. VMR-1 was associated with diabetic retinopathy (p = 0.001) and peripheral artery disease (p = 0.012); VMR-2 associated with hypertension (p < 0.001), dyslipidemia (p < 0.001), diabetic retinopathy (p < 0.001), diabetic neuropathy (p < 0.001), coronary artery disease (p = 0.001) and stroke (p < 0.05). VMR-3 associated with hypertension (p < 0.05), dyslipidemia (p < 0.001) and coronary artery disease (p < 0.05). Conclusions In this cross sectional study, whilst not causal, VMR-2 was shown to be the superior predictor of diabetic and cardiovascular complications though not demonstrative of causality in this cross-sectional study population over VMR-1, VMR-3 and the individual vitamin D concentration measurements; VMR-2 associated with both microvascular and cardiovascular indices and therefore may have utility in predicting the development of diabetic complications.

Metabolism of 25-hydroxyvitamin D in copper-laden rat: a model of Wilson's disease

1988 ◽  
Vol 254 (2) ◽  
pp. E150-E154
Author(s):  
T. O. Carpenter ◽  
M. L. Pendrak ◽  
C. S. Anast
Keyword(s):  
Vitamin D ◽  
Wilson’S Disease ◽  
Wilson's Disease ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Hepatic Copper ◽  
25 Hydroxyvitamin D ◽  
Potential Factor

Wilson's disease results in excess tissue accumulation of copper and is often complicated by skeletal and mineral abnormalities. We investigated vitamin D metabolism in rats fed a copper-laden diet rendering hepatic copper content comparable with that found in Wilson's disease. Injection of 25-hydroxyvitamin D3 [25(OH)D3] resulted in reduced 1,25-dihydroxyvitamin D [1,25(OH)2D] levels in copper-intoxicated rats. In vitro 25(OH)D-1 alpha-hydroxylase activity was impaired in renal mitochondria from copper-intoxicated animals. Activity was also inhibited in mitochondria from controls when copper was added to incubation media. Impaired conversion of 25(OH)D to 1,25(OH)2D occurs in copper intoxication and suggests that altered vitamin D metabolism is a potential factor in the development of bone and mineral abnormalities in Wilson's disease.

scholarly journals Association of Differing Qatari Genotypes with Vitamin D Metabolites

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Youssra Dakroury ◽  
Alexandra E. Butler ◽  
Soha R. Dargham ◽  
Aishah Latif ◽  
Amal Robay ◽  
...  
Keyword(s):  
Vitamin D ◽  
Skin Pigmentation ◽  
Genetic Differences ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Increased Risk ◽  
25 Hydroxyvitamin D

Objective. Genetic studies have identified four Qatari genotypes: Q1 Arab, Bedouin; Q2 Asian/Persian; Q3 African; and a fourth admixed group not fitting into the previous 3 groups. This study was undertaken to determine if there was an increased risk of deficiency of vitamin D and its metabolites associated with differing genotypes, perhaps due to genetic differences in skin pigmentation. Methods. 398 Qatari subjects (220 type 2 diabetes and 178 controls) had their genotype determined by Affymetrix 500 k SNP arrays. Total values of 1,25-dihydroxyvitamin D (1,25(OH)2D), 25-hydroxyvitamin D (25(OH)D), 24,25-dihydroxyvitamin D (24,25(OH)2D), and 25-hydroxy-3epi-vitamin D (3epi-25(OH)D) concentrations were measured by the LC-MS/MS analysis. Results. The distribution was as follows: 164 (41.2%) genotyped Q1, 149 (37.4%) genotyped Q2, 31 (7.8%) genotyped Q3, and 54 (13.6%) genotyped “admixed.” Median levels of 25(OH)D and 3epi-25(OH)D did not differ across Q1, Q2, Q3, and “admixed” genotypes, respectively. 1,25(OH)2D levels were lower (p<0.04) between Q2 and the admixed groups, and 24,25(OH)2D levels were lower (p<0.05) between Q1 and the admixed groups. Vitamin D metabolite levels were lower in females for 25(OH)D, 1,25(OH)2D (p<0.001), and 24,25(OH)2D (p<0.006), but 3epi-25(OH)D did not differ (p<0.26). Diabetes prevalence was not different between genotypes. Total 1,25(OH)2D (p<0.001), total 24,25(OH)2D (p<0.001), and total 3epi-25(OH)D (p<0.005) were all significantly lower in diabetes patients compared to controls whilst the total 25(OH)D was higher in diabetes than controls (p<0.001). Conclusion. Whilst 25(OH)D levels did not differ between genotype groups, 1,25(OH)2D and 24,25(OH)2D were lower in the admixed group, suggesting that there are genetic differences in vitamin D metabolism that may be of importance in a population that may allow a more targeted approach to vitamin D replacement. This may be of specific importance in vitamin D replacement strategies with the Q2 genotype requiring less, and the other genotypes requiring more to increase 1,25(OH)2D. Whilst overall the group was vitamin D deficient, total 25(OH)D was higher in diabetes, but 1,25(OH)2D, 24,25(OH)2D, and 3epi-25(OH)D were lower in diabetes that did not affect the relationship to genotype.

scholarly journals Reshaping the way we view vitamin D signalling and the role of vitamin D in health

2004 ◽  
Vol 17 (2) ◽  
pp. 241-248 ◽  
Author(s):  
James C. Fleet ◽  
Jie Hong ◽  
Zhentao Zhang
Keyword(s):  
Vitamin D ◽  
Transcriptional Activation ◽  
Mode Of Action ◽  
Uv Light ◽  
Active Form ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Molecular Mode

AbstractAlthough the biological requirement for vitamin D can be met by epidermal exposure to UV light, there are a number of conditions where this production does not occur or is not sufficient to meet biological needs. When this happens, vitamin D must be consumed and is a nutrient. However, two distinct observations have caused researchers to rethink certain dogma in vitamin D biology. First, it appears that in addition to the hormonally active form of 1,25 dihydroxyvitamin D (1,25(OH)2D), circulating levels of 25 hydroxyvitamin D have a critical importance for optimal human health. This and other data suggest that extra-renal production of 1,25(OH)2D contributes to Ca homeostasis and cancer prevention. Second, in addition to its role in the transcriptional activation of genes through the vitamin D receptor there is now compelling evidence that 1,25(OH)2D has a second molecular mode of action; the rapid activation of second-messenger and kinase pathways. The purpose of this second mode of action is only now being explored. The present review will discuss how these two areas are reshaping our understanding of vitamin D metabolism and action.

scholarly journals Associations between Genetic Variants in the Vitamin D Metabolism Pathway and Severity of COVID-19 among UAE Residents

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3680
Author(s):  
Fatme Al-Anouti ◽  
Mira Mousa ◽  
Spyridon N. Karras ◽  
William B. Grant ◽  
Zainab Alhalwachi ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
United Arab Emirates ◽  
Genetic Variants ◽  
Nucleotide Polymorphisms ◽  
Genetic Determinants ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
Potential Risk Factors ◽  
25 Hydroxyvitamin D

Vitamin D has many effects on cells in the immune system. Many studies have linked low vitamin D status with severity of COVID-19. Genetic variants involved in vitamin D metabolism have been implicated as potential risk factors for severe COVID-19 outcomes. This study investigated how genetic variations in humans affected the clinical presentation of COVID-19. In total, 646 patients with SARS-CoV-2 infection were divided into two groups: noncritical COVID-19 (n = 453; 70.12%) and a critical group (n = 193; 29.87%). Genotype data on the GC, NADSYN1, VDR, and CYP2R1 genes along with data on serum 25-hydroxyvitamin D levels were compiled in patients admitted to a major hospital in the United Arab Emirates between April 2020 and January 2021. We identified 12 single-nucleotide polymorphisms associated with the critical COVID-19 condition: rs59241277, rs113574864, rs182901986, rs60349934, and rs113876500; rs4944076, rs4944997, rs4944998, rs4944979, and rs10898210; and rs11574018 and rs11574024. We report significant associations between genetic determinants of vitamin D metabolism and COVID-19 severity in the UAE population. Further research needed to clarify the mechanism of action against viral infection in vitamin D deficiency. These variants could be used with vaccination to manage the spread of SARS-CoV-2 and could be particularly valuable in populations in which vitamin D deficiency is common.

Effects of parathyroid hormone on puppies during development of Ca and vitamin D deficiency

1985 ◽  
Vol 249 (6) ◽  
pp. E568-E576 ◽  
Author(s):  
K. M. Wong ◽  
L. Klein ◽  
B. Hollis
Keyword(s):  
Vitamin D ◽  
Bone Resorption ◽  
Vitamin D Deficiency ◽  
Maximal Response ◽  
Deficient Diet ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Entire Experiment ◽  
Parathyroid Extract

The acute effects of parathyroid extract (PTE) were studied repeatedly in young dogs (prelabeled with 45Ca and [3H]tetracycline) during the development of calcium (Ca) and vitamin D deficiency. Blood Ca and radioactivity changes were monitored sequentially after subcutaneous PTE, injected seven times over 63 days. In control dogs, all sequential responses to acute PTE challenges were constant in both magnitude of increase and time at which maximum response occurred over the entire experiment. Under chronic Ca and D deficiency, plasma 25-hydroxyvitamin D in experimental dogs decreased continuously to very low levels at 63 days, whereas 1,25-dihydroxyvitamin D initially increased to a maximum at 32 days and thereafter decreased. In response to an acute challenge of PTE, dogs on the deficient diet for 3 and 10 days showed a greater response of blood Ca and 45Ca than the controls but subsequently showed a smaller response than controls after 49 and 63 days on the deficient diet. Compared with control dogs, the time of maximal response of blood Ca and 45Ca to PTE occurred much earlier in dogs that were on the deficient diet for 35-63 days. The blood [3H]tetracycline response (index of bone resorption) to exogenous PTE in the deficient dogs, however, was constant and similar to that of the control dogs during the entire period. The data suggest that the bone resorption response to PTE was normal in Ca- and D-deficient puppies with hypocalcemia.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals IGF-I and GH stimulate Phex mRNA expression in lungs and bones and 1,25-dihydroxyvitamin D(3) production in hypophysectomized rats

2002 ◽  
pp. 97-105 ◽  
Author(s):  
E Zoidis ◽  
M Gosteli-Peter ◽  
C Ghirlanda-Keller ◽  
L Meinel ◽  
J Zapf ◽  
...  
Keyword(s):  
Vitamin D ◽  
Mrna Expression ◽  
Type I ◽  
Serum Osteocalcin ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Igf I ◽  
Hypophysectomized Rats ◽  
25 Hydroxyvitamin D

OBJECTIVE: X-linked hypophosphatemia, a renal phosphate (Pi)-wasting disorder with defective bone mineralization, is caused by mutations in the PHEX gene (a Pi-regulating gene with homology to endopeptidases on the X chromosome). We wondered whether changes in Phex and neprilysin (NEP) (another member of the family of zinc endopeptidases) mRNA expression could be observed in relation to vitamin D and Pi metabolism during GH- and IGF-I-stimulated growth of hypophysectomized rats. DESIGN: Animals were infused s.c. for 2 days with vehicle, 200 mU (67 microg) GH or 300 microg IGF-I/rat per 24 h. We determined serum osteocalcin and osteocalcin mRNA in bone, Phex mRNA in bone and lungs, serum 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) and serum Pi levels, and renal expression of 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase), of 25-hydroxyvitamin D(3)-24-hydroxylase (24-hydroxylase) and of the Na-dependent Pi-cotransporter type I and II (Na(d)Pi-I and -II). RESULTS: As compared with vehicle-treated controls, body weight and tibial epiphyseal width significantly increased in GH- and IGF-I-treated animals. Serum osteocalcin and osteocalcin mRNA levels in bone, Phex mRNA in bone and lungs, serum 1,25-(OH)(2)D(3) and renal 1alpha-hydroxylase mRNA rose concomitantly, whereas expression of NEP in lungs was barely affected and renal 24-hydroxylase mRNA decreased. Na(d)Pi-I and -II gene expression in the kidney and serum Pi levels remained unchanged. CONCLUSIONS: Our findings suggest a coordinate regulation of Phex mRNA expression in lungs and bone and vitamin D metabolism during GH- and IGF-I-stimulated growth.

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