Studies on the measurement of 25-hydroxy vitamin D in human saliva

Fairney, Angela; Saphier, P. W.

doi:10.1079/bjn19870005

Cited by 21 publications

(8 citation statements)

References 18 publications

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“…Since the human corneal epithelium is capable of synthesizing vitamin D [9], we speculate that the increased level observed in the tears could be due to vitamin D produced by the corneal epithelium following exposure of the eye to UVB rays present in sunlight. Unlike tear fluid, 25-hydroxyvitamin D in the saliva (another non-invasive source for measuring vitamin D) was reported to be manifold lower than that of the serum [25, 26]. Hence, more detailed studies are required to confirm increased 25-hydroxyvitamin D in tear fluid and understand the source that contributes to it.…”

Section: Discussionmentioning

confidence: 99%

Correlation between tear fluid and serum vitamin D levels

et al. 2016

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Background: Vitamin D deficiency is associated with a range of systemic diseases including ocular disorders. The objective of this study is to measure tear vitamin D levels and investigate the correlation between serum and tear vitamin D levels. Methods: A total of 48 healthy volunteers without any systemic and ocular disease were recruited for this observational cohort study. Serum was collected using clot activator coated Vacutainer® Plus tubes. Tear fluid was collected using Schirmer's strips. Serum and tear total 25-hydroxyvitamin D levels were measured by competitive chemiluminescent ELISA and the correlation between the levels were studied. Results: The measured serum 25-hydroxyvitamin D level ranged between 3.3 and 27.5 ng/ml (Mean ± SEM, 9.4 ± 0. 7 ng/ml; Median 8.4 ng/ml). Significantly (p < 0.0001) higher level of 25-hydroxyvitamin D was detected in the tears (Mean ± SEM, 17.0 ± 1.6 ng/ml; Range 3.2-45.8 ng/ml; Median, 16.3 ng/ml) compared to serum. An average of~2 fold (Mean ± SEM, 1.9 ± 0.2; Range 0.4-5.8; Median, 1.7) higher 25-hydroxyvitamin D was observed in tears compared to serum in the subjects. In addition, a positive correlation was observed between serum and tear 25-hydroxyvitamin D levels (r = 0.5595; p < 0.0001). Conclusions: A higher level of 25-hydroxyvitamin D was observed in the tear fluid compared to that of the serum. It would be beneficial to consider tear vitamin D levels to study its role with reference to ocular surface diseases.

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Section: Discussionmentioning

confidence: 99%

Correlation between tear fluid and serum vitamin D levels

et al. 2016

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“…LC-MS/MS has also been adapted to saliva samples, with initial small studies showing salivary 25(OH)D 3 to be well correlated with the serum levels (r 5 0.83 po0.01) despite lower concentrations attributable to the absence of 25(OH)D bound to DPB [87,88]. Larger studies investigating the validity of saliva samples and the impact of 25(OH)D 2 (amongst other issues) are necessary before widespread clinical use.…”

Section: (Oh)d In Alternative Biological Samplesmentioning

confidence: 99%

Assessing vitamin D status: Pitfalls for the unwary

Lai

Lucas

Clements

et al. 2010

Molecular Nutrition Food Res

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The use of vitamin D testing has grown rapidly in the recent times as a result of increased interest in the role of vitamin D in health. Although the generally accepted measure of vitamin D status is circulating 25(OH)D concentration, there is little consensus on which assay method should be used. Commonly used assays include competitive protein-binding assay, RIA, enzyme immunoassay, chemiluminescence immunoassays, HPLC, and LC-MS/MS, each with its own advantages and disadvantages. However, there is significant interassay and interlaboratory variability in measurements. Our simulation of the published data showed that using a deficiency cut-point of 50 nmol/L, 57% of samples assessed using a chemiluminescence immunoassay were classified as deficient compared with 41% of samples assessed using LC-MS/MS; a 20% misclassification rate. Similar rates of misclassification were seen at 75 nmol/L. This has implications for clinical practice and decision limits for vitamin D supplementation, suggesting that cut-points should be assay specific rather than universal and that greater harmonization between laboratories is required. Newer assays using alternative biological samples to determine the circulating 25(OH)D have been proposed and advances in the genetics of vitamin D and the role of vitamin D-binding protein may improve future assay accuracy.

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“…The link between vitamin D levels and caries is multifactorial and includes genetic, environmental, nutritional, and socioeconomic factors. There are detectable amounts of vitamin D in saliva ranging from 105 to 1,000 pg/ml, depending on the individual, diet, and time of day (18). One study found that increased serum vitamin D levels were associated with lower occurrence of dental maladies, including caries and hypomineralization (19).…”

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confidence: 99%

Vitamin D Compounds Are Bactericidal against Streptococcus mutans and Target the Bacitracin-Associated Efflux System

Saputo

Faustoferri

Quivey

2018

Antimicrob Agents Chemother

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Vitamin D analogs were identified as compounds that induced lysis of planktonic cultures of in a high-throughput screen of FDA-approved drugs. Previous studies have demonstrated that certain derivatives of vitamin D possess lytic activity against other bacteria, though the mechanism has not yet been established. Through the use of a combinatorial approach, the vitamin D derivative doxercalciferol was shown to act synergistically with bacitracin, a polypeptide-type drug that is known to interfere with cell wall synthesis, suggesting that doxercalciferol may act in a bacitracin-related pathway. Innate resistance to bacitracin is attributed to efflux by a conserved ABC-type transporter, which in is encoded by the operon. possesses two characterized mechanisms of resistance to bacitracin, the ABC transporter, bacitracin resistance (Mbr) cassette, consisting of MbrABCD, and the rhamnose-glucose polysaccharide (Rgp) system, RgpABCDEFGHI. Loss of function of the transporter in and mutants exacerbated the effect of the combination of doxercalciferol and bacitracin. Despite conservation of a transporter homologous to, the combination of doxercalciferol and bacitracin appeared to be synergistic only in streptococcal species. We conclude that vitamin D derivatives possess lytic activity against and act through a mechanism dependent on the bacitracin resistance mechanism of MbrABCD.

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Studies on the measurement of 25-hydroxy vitamin D in human saliva

Cited by 21 publications

References 18 publications

Correlation between tear fluid and serum vitamin D levels

Correlation between tear fluid and serum vitamin D levels

Assessing vitamin D status: Pitfalls for the unwary

Vitamin D Compounds Are Bactericidal against Streptococcus mutans and Target the Bacitracin-Associated Efflux System

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