The plasma binding protein for vitamin D is a site of discrimination against vitamin D-2 compounds by the chick

DeLuca, Hector F.; Nakada, Masaki; Tanaka, Yoko; Siciński, Rafał R.; Phelps, Mary

doi:10.1016/0304-4165(88)90145-6

Cited by 14 publications

(6 citation statements)

References 21 publications

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“…The exact biochemical and physiological nature of the discrimination between ergocalciferol and cholecalciferol is yet to be determined. Different scenarios have been suggested in a variety of species, like a more rapid metabolism and clearance from plasma of ergocalciferol than cholecalciferol due to lower affinity of the plasmabased vitamin D-binding protein for ergocalciferol than for cholecalciferol, or a higher affinity of the liver-based vitamin D-25-hydroxylase enzyme for cholecalciferol than ergocalciferol, or maybe a combination of both (Nilsson et al, 1972;DeLuca et al, 1988;Armas et al, 2004). The latter is to some extend indirectly supported by the present results, because the relation between 25(OH)-ergocalciferol and ergocalciferol was half of the relation between 25(OH)-cholecalciferol and cholecalciferol after 24 h, indicating that ergocalciferol is hydroxylated less frequently than cholecalciferol by the liver enzymes.…”

Section: Discussionmentioning

confidence: 99%

Stability in the rumen and effect on plasma status of single oral doses of vitamin D and vitamin E in high-yielding dairy cows

Hymøller

Jensen

2010

Journal of Dairy Science

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The ruminal fate of the fat-soluble vitamins D and E was studied in dairy cows. Ten to 15 kg of ruminal contents was taken from each cow through a ruminal fistula. A sample was taken out (0-h sample) and the rest of the contents were mixed with 4,360 mg of all-rac-α-tocopheryl acetate (vitamin E; study 1) or 4,360 mg of all-rac-α-tocopheryl acetate, 250 mg of ergocalciferol (vitamin D(2)), and 250 mg of cholecalciferol (vitamin D(3); study 2). After mixing, the ruminal contents were returned to the respective cows. Blood was collected 0, 6, 24, and 30 h after introducing the vitamins into the rumen. Samples of ruminal contents were collected at 0, 1, 2, 4, 6, 24, and 30 h (in vivo). From the 1-h sample, 6 subsamples from each cow were incubated at 37 °C and taken out at 2, 4, 6, 12, 24, and 30 h (in vitro). In vivo concentrations of added α-tocopherol, ergocalciferol, and cholecalciferol in the rumen first increased and subsequently declined due to dilution effects of eating and passage out of the rumen. The level of the free-alcohol form of α-tocopherol from the natural content in feed was constant throughout the in vivo study, in contrast to the content of total α-tocopherol, which indicated that no hydrolysis of the acetate form into alcohol form happened in the rumen. In vitro, all added vitamins were found at constant levels; hence, none of the added vitamins were degraded in ruminal contents. The concentration of α-tocopherol in plasma increased at a rate per milligram of ruminally introduced α-tocopherol below the rate of the increase in plasma ergocalciferol or cholecalciferol metabolites per milligram of introduced ergocalciferol or cholecalciferol, respectively, over 24h. In conclusion, ergocalciferol, cholecalciferol, and α-tocopheryl acetate proved to be stable in the rumen and in ruminal contents from high-yielding dairy cows. Changes in plasma concentrations of the vitamins relative to the amount of vitamin introduced to the rumen indicated a lower effect on plasma status of ergocalciferol than of cholecalciferol, and an even lower effect of α-tocopherol. The limited plasma response after a single dose of α-tocopheryl acetate led to the conclusion that oral single dose therapy with all-rac-α-tocopheryl acetate is of limited physiological value.

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Section: Discussionmentioning

confidence: 99%

Stability in the rumen and effect on plasma status of single oral doses of vitamin D and vitamin E in high-yielding dairy cows

Hymøller

Jensen

2010

Journal of Dairy Science

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“…Although research in cats is limited, one study suggests a lower bioavailability of vitamin D 2 compared to D 3 in felines (27). Cats are not the only species that appear to discriminate against vitamin D 2 ; a similar pattern is observed in pigs (28), chicks (28,29), horses (30), and monkeys (31,32). Rats, on the other hand, exhibit a preference for vitamin D 2 (28,33).…”

Section: Introductionmentioning

confidence: 84%

Effects of Vitamin D2 and 25-Hydroxyvitamin D2 Supplementation on Plasma Vitamin D Epimeric Metabolites in Adult Cats

Ruggiero

Backus

2021

Front. Vet. Sci.

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Feline vitamin D status is based on dietary consumption but metabolism of this essential nutrient and the efficacy of supplementation forms are poorly described in cats. The aim of this study was to further elucidate the metabolites of vitamin D2 in cats and to compare the effectiveness of vitamin D2 and 25(OH)D2 for increasing feline vitamin D status. Eight adult male castrated domestic shorthair cats received vitamin D2 or 25(OH)D2 in a single crossover design. Vitamin D2 was dosed daily in a molar equivalent dosage to vitamin D3 ingested in the diet while 25(OH)D2 was provided at a daily dose of 20% molar equivalent intake of dietary vitamin D3 based on its expected higher potency. Plasma concentrations of 25-hydroxyvitamin D epimers were evaluated at baseline then every 2 weeks for a total of 10 weeks. Analysis of multiple vitamin D metabolite concentrations was completed at the end of each supplementation period, followed by a washout period preceding the second phase of the crossover trial. Results showed that supplementation with 25(OH)D2 more effectively and rapidly raised circulating 25(OH)D2 levels in cat plasma compared to vitamin D2. Formation of C-3 epimers of 25(OH)D3, 25(OH)D2, and 24,25R(OH)2D3, but not 24,25(OH)2D2, were observed in feline plasma. The abundant concentrations of epimeric forms of vitamin D metabolites found in circulation suggest that these metabolites should be considered during vitamin D analyses in cats. Further studies using 25(OH)D and vitamin D2 forms are needed to conclude safety and efficacy of these vitamers for supplementation in this species.

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“…Supplementation with both vitamin D3 and 25(OH)D3 has been shown to increase the vitamin D content of egg yolks, a potential fortification method for human consumption [172]. Supplementation with D3 metabolites rather than D2 is more effective in increasing vitamin D content of egg yolks [173], possibly due to 25(OH)D2 being less well bound to the VDBP than 25(OH)D3 in chickens, rendering it less effective [174].…”

Section: Poultrymentioning

confidence: 99%

Vitamin D Metabolism and Profiling in Veterinary Species

2020

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The demand for vitamin D analysis in veterinary species is increasing with the growing knowledge of the extra-skeletal role vitamin D plays in health and disease. The circulating 25-hydroxyvitamin-D (25(OH)D) metabolite is used to assess vitamin D status, and the benefits of analysing other metabolites in the complex vitamin D pathway are being discovered in humans. Profiling of the vitamin D pathway by liquid chromatography tandem mass spectrometry (LC-MS/MS) facilitates simultaneous analysis of multiple metabolites in a single sample and over wide dynamic ranges, and this method is now considered the gold-standard for quantifying vitamin D metabolites. However, very few studies report using LC-MS/MS for the analysis of vitamin D metabolites in veterinary species. Given the complexity of the vitamin D pathway and the similarities in the roles of vitamin D in health and disease between humans and companion animals, there is a clear need to establish a comprehensive, reliable method for veterinary analysis that is comparable to that used in human clinical practice. In this review, we highlight the differences in vitamin D metabolism between veterinary species and the benefits of measuring vitamin D metabolites beyond 25(OH)D. Finally, we discuss the analytical challenges in profiling vitamin D in veterinary species with a focus on LC-MS/MS methods.

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The plasma binding protein for vitamin D is a site of discrimination against vitamin D-2 compounds by the chick

Cited by 14 publications

References 21 publications

Stability in the rumen and effect on plasma status of single oral doses of vitamin D and vitamin E in high-yielding dairy cows

Stability in the rumen and effect on plasma status of single oral doses of vitamin D and vitamin E in high-yielding dairy cows

Effects of Vitamin D2 and 25-Hydroxyvitamin D2 Supplementation on Plasma Vitamin D Epimeric Metabolites in Adult Cats

Vitamin D Metabolism and Profiling in Veterinary Species

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