scholarly journals DEVELOPMENT AND VALIDATION OF IMMUNOENZYME TEST-SYSTEM FOR DETERMINATION OF 25-HYDROXYVITAMIN D IN BLOOD SERUM

2016 ◽  
Vol 9 (2) ◽  
pp. 28-36 ◽  
Author(s):  
A. O. Mazanova ◽  
Keyword(s):  
Blood Serum ◽  
Test System ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Development And Validation

Rapid method for measuring physiological concentrations of 25-hydroxyvitamin D levels in blood serum

1985 ◽  
Vol 153 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Krystyna Prószyńska ◽  
Jacek Łukaszkiewicz ◽  
Nella Jarocewicz ◽  
Roman S. Lorenc
Keyword(s):  
Blood Serum ◽  
Rapid Method ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D

scholarly journals Development and validation of an interview-administered FFQ for assessment of vitamin D and calcium intakes in Finnish women

2016 ◽  
Vol 115 (6) ◽  
pp. 1100-1107 ◽  
Author(s):  
Suvi T. Itkonen ◽  
Maijaliisa Erkkola ◽  
Essi Skaffari ◽  
Pilvi Saaristo ◽  
Elisa M. Saarnio ◽  
...  
Keyword(s):  
Vitamin D ◽  
Food Groups ◽  
Hydroxyvitamin D ◽  
Supplement Use ◽  
Food Records ◽  
Supplemental Vitamin ◽  
25 Hydroxyvitamin D ◽  
Mean Differences ◽  
Development And Validation ◽  
Supplement Intake

AbstractIncreased vitamin D fortification of dairy products has increased the supply of vitamin D-containing products with different vitamin D contents on the market in Finland. The authors developed a ninety-eight-item FFQ with eight food groups and with a question on supplementation to assess dietary and supplemental vitamin D and Ca intakes in Finnish women (60ºN). The FFQ was validated in subgroups with different habitual vitamin D supplement use (0–57·5 µg/d) against the biomarker serum 25-hydroxyvitamin D (S-25(OH)D) and against 3-d food records (FR) (n29–67). Median total vitamin D intake among participants was 9·4 (range 1·6–30·5) µg/d. Spearman’s correlations for vitamin D and Ca ranged from 0·28 (P0·146, FFQv. S-25(OH)D, persons not using supplements) to 0·75 (P<0·001, FFQv. FR, supplement use included). The correlations between the FFQ and S-25(OH)D concentrations improved within increasing supplement intake. The Bland–Altman analysis showed wide limits of agreement between FFQ and FR: for vitamin D between −7·8 and 8·8 µg/d and for Ca between −938 and 934 mg/d, with mean differences being 0·5 µg/d and 2 mg/d, respectively. The triads method was used to calculate the validity coefficients of the FFQ for vitamin D, resulting in a mean of 1·00 (95 % CI 0·59, 1·00) and a range from 0·33 to 1·00. The perceived variation in the estimates could have been avoided with a longer FR period and larger number of participants. The results are comparable with earlier studies, and the FFQ provides a reasonable estimation of vitamin D and Ca intakes.

Simultaneous determination of 25-hydroxy- and 1,25-dihydroxyvitamin D from a single sample by dual-cartridge extraction.

1984 ◽  
Vol 30 (1) ◽  
pp. 56-61 ◽  
Author(s):  
P C Kao ◽  
D W Heser
Keyword(s):  
High Performance ◽  
Vitamin D Metabolites ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Hydroxylated Metabolites ◽  
Silica Cartridge ◽  
25 Hydroxyvitamin D ◽  
The Mean

Abstract With this dual-cartridge system we extract 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] from a single serum sample by using a nonpolar octadecylsilanol silica cartridge to adsorb the vitamin D metabolites and other nonpolar substances; the polar substances wash through the cartridge. The eluted material is then applied to a second alkylamine cartridge, which adsorbs the relatively polar hydroxylated metabolites; the less-polar substances are washed from the second cartridge. Elution from the second cartridge purifies and also separates 25(OH)D and 1,25(OH)2D with analytical recoveries near 90%. The monohydroxyl metabolites are determined by "high-performance" liquid chromatography (HPLC); the dihydroxyl metabolites are further purified by HPLC and determined by radioreceptor assay according to established procedures. Mean (+/- SD) winter normal values (34 subjects of both sexes; blood drawn in mid-April) were 18 +/- 5 micrograms/L for 25(OH)D and 25 +/- 7 ng/L for 1,25(OH)2D. In nine laboratory volunteers, the mean increase in the serum 25(OH)D3 value 5 h after ingestion of 50 micrograms of 25-hydroxycholecalciferol (Calderol) was 9 (SD 4) micrograms/L.

scholarly journals Comparison of Commercially Available 125I-based RIA Methods for the Determination of Circulating 25-Hydroxyvitamin D

2000 ◽  
Vol 46 (10) ◽  
pp. 1657-1661 ◽  
Author(s):  
Bruce W Hollis
Keyword(s):  
Metabolic Bone Disease ◽  
Detection Method ◽  
Primary Antibody ◽  
Ultraviolet Detection ◽  
Hydroxyvitamin D ◽  
Metabolic Bone ◽  
Assay Performance ◽  
Background Measurement ◽  
25 Hydroxyvitamin D

Abstract Background: Measurement of circulating 25-hydroxyvitamin D [25(OH)D] is important in the management of metabolic bone disease. The aim of this study was to compare two widely used methods for the quantification of circulating 25(OH)D with attention to their abilities to measure 25-hydroxylated ergocalciferol (vitamin D2) [25(OH)D2] and cholecalciferol (vitamin D3) [25(OH)D3]. Methods: We used two commercially available, Food and Drug Administration-approved, radioiodine (125I)-based RIA kits for the detection of 25(OH)D (DiaSorin, Stillwater, MN and IDS Ltd, Tyne and Wear, United Kingdom). These methods were tested for general assay performance, including antibody specificity. Results were compared with those of an HPLC-based direct ultraviolet detection method. Results: Within- and between-run CVs were ≤10%. Both methods quantitatively recovered 25(OH)D3 added to serum, but only the DiaSorin kit quantitatively recovered 25(OH)D2. The primary antibody in the IDS kit had unequal reactivities with pure 25(OH)D2 and 25(OH)D3, whereas the DiaSorin primary antibody reacted with them equally. In 50 patient samples assayed by HPLC, the IDS method, but not the DiaSorin method, underestimated total circulating 25(OH)D when significant circulating 25(OH)D2 was present in patient samples. Conclusions: Some immunoassays may underestimate total 25(OH)D when 25(OH)D2 constitutes an appreciable part of the total.

Sign in / Sign up

Export Citation Format

Share Document