scholarly journals Serum 25-hydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3 concentrations in adult dogs are more substantially increased by oral supplementation of 25-hydroxyvitamin D3 than by vitamin D3

2017 ◽  
Vol 6 ◽  
Author(s):  
Lauren R. Young ◽  
Robert C. Backus
Keyword(s):  
Vitamin D ◽  
Hplc Method ◽  
Vitamin D Status ◽  
Dihydroxyvitamin D3 ◽  
Oral Supplementation ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Supplementation Period ◽  
Single Cross ◽  
25 Hydroxyvitamin D

AbstractWe previously found a weak response in serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations when dogs were supplemented with oral vitamin D3 (D3). In the present study, we determined the relative potency of oral 25(OH)D3 compared with D3 for increasing vitamin D status in dogs with low serum 25(OH)D concentrations. Four male and three female, 4-year-old, intact, lean, genetically related, Chinese-crested/beagle dogs were studied in a randomised, single cross-over trial. After feeding a low-vitamin D diet (<4 IU/100 g) for 30 d, four dogs received daily D3 supplementation at 2·3 µg/kg body weight0·75, while three dogs received a molar equivalency as 25(OH)D3. The supplements, dissolved in ethanol, were applied to a commercial treat for consumption. Serum 25(OH)D3 and 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) were analysed weekly using a validated HPLC method. Both supplementations increased (P ≤ 0·01) serum 25(OH)D3 concentrations. However, oral 25(OH)D3 resulted in greater (P < 0·0001) concentrations than D3 by week 1, with a difference of 173 % (P < 0·0001) by week 2. The supplementation period was limited to 14 d after serum 25(OH)D3 concentrations were not appearing to plateau. Thereafter, a washout period of 1 month separated the cross-over. Following 25(OH)D3, but not D3 supplementation, serum 24R,25(OH)2D3 concentrations increased (P ≤ 0·02), 3 to 5 weeks after initiating supplementation. Vitamin D status, as indicated by serum 25(OH)D3 and 24R,25(OH)2D3 concentrations, is more rapidly and efficiently increased in adult dogs by oral supplementation of 25(OH)D3 than D3.

scholarly journals The Effect of Vitamin D Supplementation on its Metabolism and the Vitamin D Metabolite Ratio

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2539 ◽  
Author(s):  
Vito Francic ◽  
Stan R. Ursem ◽  
Niek F. Dirks ◽  
Martin H. Keppel ◽  
Verena Theiler-Schwetz ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Supplementation ◽  
Vitamin D Metabolites ◽  
Vitamin D Status ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Correlation And Regression Analysis ◽  
Metabolite Ratio ◽  
25 Hydroxyvitamin D ◽  
Additional Value

25-hydroxyvitamin D (25(OH)D) is commonly measured to assess vitamin D status. Other vitamin D metabolites such as 24,25-dihydroxyvitamin D (24,25(OH)2D) provide additional insights into vitamin D status or metabolism. Earlier studies suggested that the vitamin D metabolite ratio (VMR), calculated as 24,25(OH)2D/25(OH)D, could predict the 25(OH)D increase after vitamin D supplementation. However, the evidence for this additional value is inconclusive. Therefore, our aim was to assess whether the increase in 25(OH)D after supplementation was predicted by the VMR better than baseline 25(OH)D. Plasma samples of 106 individuals (25(OH)D < 75 nmol/L) with hypertension who completed the Styrian Vitamin D Hypertension Trial (NC.T.02136771) were analyzed. Participants received vitamin D (2800 IU daily) or placebo for 8 weeks. The treatment effect (ANCOVA) for 25(OH)D3, 24,25(OH)2D3 and the VMR was 32 nmol/L, 3.3 nmol/L and 0.015 (all p < 0.001), respectively. Baseline 25(OH)D3 and 24,25(OH)2D3 predicted the change in 25(OH)D3 with comparable strength and magnitude. Correlation and regression analysis showed that the VMR did not predict the change in 25(OH)D3. Therefore, our data do not support routine measurement of 24,25(OH)2D3 in order to individually optimize the dosage of vitamin D supplementation. Our data also suggest that activity of 24-hydroxylase increases after vitamin D supplementation.

1,25-Dihydroxyvitamin D3 downregulates the rat intestinal vitamin D3-25-hydroxylaseCYP27A

2001 ◽  
Vol 281 (2) ◽  
pp. E315-E325 ◽  
Author(s):  
Catherine Theodoropoulos ◽  
Christian Demers ◽  
Ali Mirshahi ◽  
Marielle Gascon-Barré
Keyword(s):  
Vitamin D ◽  
Direct Action ◽  
Dihydroxyvitamin D3 ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Protein Levels ◽  
25 Hydroxyvitamin D ◽  
Extrahepatic Tissues ◽  
Mrna Half Life

The vitamin D3-25-hydroxylase CYP27A is located predominantly in liver, but its expression is also detected in extrahepatic tissues. Our aim was to evaluate the regulation of CYP27A by vitamin D3 (D3) or its metabolites in rat duodena. Vitamin D-depleted rats were repleted with D3, 25-hydroxyvitamin D (25OHD), or 1,25-dihydroxyvitamin D3[1,25(OH)2D3] or acutely injected 1,25(OH)2D3 to investigate the mechanisms of action of the hormone. All D3 compounds led to a progressive decrease in CYP27A mRNA, with levels after D3 representing 20% of that observed in D depletion. 25OHD decreased CYP27A mRNA by 55%, whereas 1,25(OH)2D3 led to a 40% decrease, which was accompanied by a 31% decrease in CYP27A protein levels and an 89% decrease in enzyme activity. Peak circulating 1,25(OH)2D3 concentrations were, however, the highest in D3-repleted, followed by 25OHD- and 1,25(OH)2D3-repleted animals. 1,25(OH)2D3 resulted in a decrease in both CYP27A mRNA half-life and transcription rate. Our data illustrate that the intestine expresses the D3-25-hydroxylase and that the gene is highly regulated in vivo through a direct action of 1,25(OH)2D3 or through the local production of D3 metabolites.

Serum Calcium and Vitamin D Status of Patients with Sickle Cell Disease in Curaçao

1997 ◽  
Vol 34 (2) ◽  
pp. 170-172 ◽  
Author(s):  
Fey P L van der Dijs ◽  
Fiona R M van der Klis ◽  
Fred D Muskiet ◽  
Frits A J Muskiet
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Calcium Concentration ◽  
Vitamin D Status ◽  
Serum Concentrations ◽  
Cell Disease ◽  
Serum Calcium Concentration ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D

We measured parameters of calcium homeostasis and vitamin D status in HbSS patients (median age 8 years, range 3–19; 8 females, 10 males) and matched HbAA controls living in the tropical island of Curaçao. Serum calcium concentration in HbSS patients [2·32(0·07) mmol/L] was lower (ANCOVA, P = 0·002) than that of HbAA controls [2·44(0·14)]. None of the subjects had hypocalcaemia. There were no differences in serum concentrations of phosphate, total protein, albumin, intact parathyroid hormone (PTH), 25-hydroxyvitamin D [87(27) nmol/L in patients, 86(15) nmol/L in controls) and 1,25-dihydroxyvitamin D. There were no significant relations between PTH and 25(OH)D. We conclude that vitamin D status of HbSS patients in Curaçao is adequate.

scholarly journals Changes in serum levels of 1,25-dihydroxyvitamin D3, calcium and phosphorus with age and vitamin D status in chickens

1984 ◽  
Vol 52 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Saleh H. Sedrani
Keyword(s):  
Vitamin D ◽  
Serum Level ◽  
Sexual Maturity ◽  
Serum Levels ◽  
Minimal Amount ◽  
Dihydroxyvitamin D3 ◽  
Dietary Regimen ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D

1. The effects of vitamin D3(D3) on serum levels of 1, 25-dihydroxyvitamin D3(1, 25(OH)2D3), ionic calcium, total Ca and phosphorus in chicks were studied from the time of hatching until sexual maturity.2. Chicks fed on a diet low in D3showed a serum level of 1, 25(OH)2D3higher than that in chicks on a normal-D3diet, for both sexes and at any given age.3. A dramatic increase in the serum level of 1, 25(OH)2D3occurred in female birds approaching sexual maturity and in laying hens raised on the low-D3diet the level was five times that of their counterparts raised on a normal-D3diet.4. Theserum 1, 25(OH)2D3levelin adultmalesin thelow-D3groups wasseven timesthatofthoseon thenormal-D3diet.5. The serum level of 25-hydroxyvitamin D3remained relatively unchanged at weeks 2 and 15 in birds on a low D3intake as well as in those fed on a normal-D3diet. Nevertheless, the levels of 25-hydroxyvitamin D3were different between the two groups.6. No significant change was observed in the level of ionized serum Ca in relation to dietary regimen, but there was an increase in total Ca concentration in females with the onset of reproduction.7. The serum P level decreased gradually with age, reaching a minimum value 3 and 8 weeks before laying commenced in the groups on low- and normal-D3diets respectively. An increase was observed when the hens began laying.8. Chicks adapted to a low-D3diet by elevation of their plasma level of 1, 25(OH)2D3. The mechanism by which this is achieved is not known, but the results suggest that parathyroid hormone, Ca and P are unlikely to play roles in the adaptive increase in the level of 1, 25(OH)2D3in the blood of chicks given a minimal amount of D3. The possibility that the rate of degradation of 1, 25(OH)2D3is greatly reduced under these conditions cannot be excluded and this could account for the level of this metabolite in those birds.

Calcium-Regulating Hormones and Minerals From Birth to 18 Months of Age: A Cross-Sectional Study. I. Effects of Sex, Race, Age, Season, and Diet on Vitamin D Status

PEDIATRICS ◽  
1986 ◽  
Vol 77 (6) ◽  
pp. 883-890
Author(s):  
P. Lichtenstein ◽  
B. L. Specker ◽  
R. C. Tsang ◽  
F. Mimouni ◽  
C. Gormley
Keyword(s):  
Vitamin D ◽  
Human Milk ◽  
Binding Protein ◽  
Vitamin D Metabolites ◽  
Vitamin D Status ◽  
Vitamin D Binding Protein ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
25 Hydroxyvitamin D

The influence of sex, race, age, season, and diet (cow's milk formula v human milk) on the vitamin D and vitamin D-binding protein status in infants less than 18 months of age was investigated in this crosssectional, prospective study of 198 infants. No differences by sex were observed in serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, or vitamin D-binding protein concentrations. By race, black infants had significantly elevated serum 1,25-dihydroxyvitamin D levels relative to white infants. By age, vitamin D-binding protein concentrations increased with increasing age. By season, serum 25-hydroxyvitamin D concentrations were low in winter, whereas 1,25-dihydroxyvitamin D and vitamin D-binding protein were high in winter compared with summer. By diet, formula-fed infants had higher serum concentrations of all measured vitamin D metabolites and vitamin D-binding protein than human milk-fed infants. Thus, race, age, season, and diet exert, individually or in combination, different and significant effects on vitamin D metabolites; these should be considered in assessing infant vitamin D status.

scholarly journals Comparison of Vitamin D and 25-Hydroxyvitamin D Concentrations in Human Breast Milk between 1989 and 2016–2017

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 573
Author(s):  
Naoko Tsugawa ◽  
Mayu Nishino ◽  
Akiko Kuwabara ◽  
Honami Ogasawara ◽  
Maya Kamao ◽  
...  
Keyword(s):  
Vitamin D ◽  
Breast Milk ◽  
Sun Exposure ◽  
Stepwise Multiple Regression ◽  
Human Breast Milk ◽  
Vitamin D Status ◽  
Human Breast ◽  
Hydroxyvitamin D ◽  
Lactating Mothers ◽  
25 Hydroxyvitamin D

Background: Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016–2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016–2017) and vitamin D status in human breast milk was also evaluated. Method: Lactating mothers were recruited from three regions of Japan in 1989 (n = 72) and 2016–2017 (n = 90), and milk from 3–4 months was collected in summer and winter. The samples were strictly sealed and stored at −80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016–2017 were assessed. Results: Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016–2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D3 concentrations. Conclusion: The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.

scholarly journals Vitamin D upregulates the macrophage complement receptor immunoglobulin in innate immunity to microbial pathogens

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Annabelle G. Small ◽  
Sarah Harvey ◽  
Jaspreet Kaur ◽  
Trishni Putty ◽  
Alex Quach ◽  
...  
Keyword(s):  
Vitamin D ◽  
Innate Immunity ◽  
Surface Expression ◽  
Microbial Pathogens ◽  
Cell Surface Expression ◽  
Complement Receptor ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Multistep Process ◽  
25 Hydroxyvitamin D

AbstractVitamin D deficiency remains a global concern. This ‘sunshine’ vitamin is converted through a multistep process to active 1,25-dihydroxyvitamin D3 (1,25D), the final step of which can occur in macrophages. Here we demonstrate a role for vitamin D in innate immunity. The expression of the complement receptor immunoglobulin (CRIg), which plays an important role in innate immunity, is upregulated by 1,25D in human macrophages. Monocytes cultured in 1,25D differentiated into macrophages displaying increased CRIg mRNA, protein and cell surface expression but not in classical complement receptors, CR3 and CR4. This was associated with increases in phagocytosis of complement opsonised Staphylococcus aureus and Candida albicans. Treating macrophages with 1,25D for 24 h also increases CRIg expression. While treating macrophages with 25-hydroxyvitamin D3 does not increase CRIg expression, added together with the toll like receptor 2 agonist, triacylated lipopeptide, Pam3CSK4, which promotes the conversion of 25-hydroxyvitamin D3 to 1,25D, leads to an increase in CRIg expression and increases in CYP27B1 mRNA. These findings suggest that macrophages harbour a vitamin D-primed innate defence mechanism, involving CRIg.

scholarly journals Vitamin D-Mediated Hypercalcemia: Mechanisms, Diagnosis, and Treatment

2016 ◽  
Vol 37 (5) ◽  
pp. 521-547 ◽  
Author(s):  
Peter J. Tebben ◽  
Ravinder J. Singh ◽  
Rajiv Kumar
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Active Form ◽  
Elevated Serum ◽  
Diagnosis And Treatment ◽  
Vitamin D Metabolites ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
Stone Formers ◽  
25 Hydroxyvitamin D

AbstractHypercalcemia occurs in up to 4% of the population in association with malignancy, primary hyperparathyroidism, ingestion of excessive calcium and/or vitamin D, ectopic production of 1,25-dihydroxyvitamin D [1,25(OH)2D], and impaired degradation of 1,25(OH)2D. The ingestion of excessive amounts of vitamin D3 (or vitamin D2) results in hypercalcemia and hypercalciuria due to the formation of supraphysiological amounts of 25-hydroxyvitamin D [25(OH)D] that bind to the vitamin D receptor, albeit with lower affinity than the active form of the vitamin, 1,25(OH)2D, and the formation of 5,6-trans 25(OH)D, which binds to the vitamin D receptor more tightly than 25(OH)D. In patients with granulomatous disease such as sarcoidosis or tuberculosis and tumors such as lymphomas, hypercalcemia occurs as a result of the activity of ectopic 25(OH)D-1-hydroxylase (CYP27B1) expressed in macrophages or tumor cells and the formation of excessive amounts of 1,25(OH)2D. Recent work has identified a novel cause of non-PTH-mediated hypercalcemia that occurs when the degradation of 1,25(OH)2D is impaired as a result of mutations of the 1,25(OH)2D-24-hydroxylase cytochrome P450 (CYP24A1). Patients with biallelic and, in some instances, monoallelic mutations of the CYP24A1 gene have elevated serum calcium concentrations associated with elevated serum 1,25(OH)2D, suppressed PTH concentrations, hypercalciuria, nephrocalcinosis, nephrolithiasis, and on occasion, reduced bone density. Of interest, first-time calcium renal stone formers have elevated 1,25(OH)2D and evidence of impaired 24-hydroxylase-mediated 1,25(OH)2D degradation. We will describe the biochemical processes associated with the synthesis and degradation of various vitamin D metabolites, the clinical features of the vitamin D-mediated hypercalcemia, their biochemical diagnosis, and treatment.

scholarly journals COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1714
Author(s):  
Habiba AlSafar ◽  
William B. Grant ◽  
Rafiq Hijazi ◽  
Maimunah Uddin ◽  
Nawal Alkaabi ◽  
...  
Keyword(s):  
Vitamin D ◽  
United Arab Emirates ◽  
Blood Levels ◽  
Vitamin D Status ◽  
Hospital Visit ◽  
Serum Samples ◽  
Hydroxyvitamin D ◽  
Increased Risk ◽  
Multiethnic Population ◽  
25 Hydroxyvitamin D

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.

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