Loading...
 
Translate Register Log In Login with facebookLogin and Register

Bio-available Vitamin D is reduced by half during pregnancy – Jan 2017

Clinical Utility of Measurement of Vitamin D-Binding Protein and Calculation of Bioavailable Vitamin D in Assessment of Vitamin D Status.

Ann Lab Med. 2017 Jan;37(1):34-38. doi: 10.3343/alm.2017.37.1.34.
Kim HJ1, Ji M2, Song J3, Moon HW4, Hur M4, Yun YM5.

VitaminDWiki

Vitamin D Binding Protein is just one of 4 genes not visible to standard Vitamin D tests
Bio-available calculation does not notice the affect of CYP27B1, CYP24A1, and VDR
The active D actually getting to the cells is a function of measured D and all 4 genes

Genetics category listing contains the following

245 articles in the Genetics category

see also 300 articles in Vitamin D Receptor, 113 articles in Vitamin D Binding Protein

Vitamin D blood test misses a lot
Blood Test Misses a lot (VDW 3439)

  • Snapshot of the literature by VitaminDWiki - (subject to many future developments)
  • Vitamin D from coming from tissues (vs blood) was speculated to be 50% in 2014, andi in 2017 is speculated to be 90%
  • Note: Good results from a blood test (> 40 ng) does not mean that a good amount of Vitamin D actually gets to cells
  • A Vitamin D test in cells appears feasible (personal communication)
    However test results would vary in each tissue due to multiple genes
  • Good clues that Vitamin D is being restricted from getting to the cells
    1) A vitamin D-related health problem runs in the family
       especially if it is one of 51+ diseases related to Vitamin D Receptor
    2) Slightly increasing Vitamin D show benefits (even if conventional Vitamin D test shows an increase)
    3) Vitamin D Receptor test (<$30) scores are difficult to understand in 2016
        easier to understand the VDR 23andMe test results analyzed by FoundMyFitness in 2018
    4) Back Pain
        probably want at least 2 clues before taking adding vitamin D, Omega-3, Magnesium, Resveratrol, etc
          The founder of VitaminDWiki took action with clues #3&4


Note: Vitamin D Binding Protein = GC


 Download the PDF from VitaminDWiki

BACKGROUND:
The associations of vitamin D deficiency with various clinical conditions highlighted the importance of vitamin D testing. Currently, clinicians measure only the total 25-hydroxyvitamin D [25(OH)D] concentration, regardless of its bioavailability. We aimed to determine the effect of vitamin D-binding protein (VDBP) on 25(OH)D bioavailability.
METHODS:
Serum samples were collected from 60 healthy controls, 50 pregnant women, and 50 patients in intensive care units (ICUs). Total 25(OH)D was quantified by liquid chromatography with tandem mass spectrometry, and VDBP levels were determined by using an ELISA kit (R&D Systems, USA). The bioavailable 25(OH)D levels were calculated by using total 25(OH)D, VDBP, and albumin concentrations.
RESULTS:
In comparison with healthy controls, the total 25(OH)D concentration was significantly lower in ICU patients (median, 11.65 vs 18.25 ng/mL; P<0.00001), but no significant difference was noted between pregnant women (18.25 ng/mL) and healthy controls. The VDBP level was significantly lower in ICU patients (95.58 vs 167.18 μg/mL, P=0.0002) and higher in pregnant women (225.01 vs 167.18 μg/mL, P=0.008) compared with healthy controls. Nonetheless, the calculated bioavailable 25(OH)D levels of ICU patients and pregnant women were significantly lower than those of healthy controls (1.97 and 1.93 ng/mL vs 2.56 ng/mL; P=0.0073 and 0.0027).
CONCLUSIONS:
A single marker of the total 25(OH)D level is not sufficient to accurately evaluate vitamin D status, especially in pregnant women. In cases where VDBP concentrations may be altered, VDBP measurements and bioavailable 25(OH)D calculations may help to determine vitamin D status accurately.

PMID: 27834063 DOI: 10.3343/alm.2017.37.1.34


Fig. 2. Comparison of total 25-hydroxyvitamin D [25(OH)D], vitamin D-binding protein (VDBP), and calculated bioavailable 25(OH)D by gestational stage.

Image

  • (A) Total 25(OH)D levels were not significantly different between the 1st and 2nd and 3rd trimesters (median, interquartile range: 1st trimester: 18.20, 15.07-23.87 ng/mL; 2nd and 3rd trimesters: 18.30, 13.75-25.70 ng/mL).
  • (B) VDBP levels during the 2nd and 3rd trimesters were significantly higher than those during the 1st trimester (1st trimester: 102.20, 84.75-259.90 µg/mL, 2nd and 3rd trimesters: 273.65, 163.75-453.98 µg/mL).
  • (C) The calculated bioavailable 25(OH)D level in the 2nd and 3rd trimesters was significantly lower than that in the 1st trimester (1st trimester: 4.19, 2.09-5.67 ng/mL; 2nd and 3rd trimesters, 1.73, 0.90-2.43 ng/mL).
  • P values were calculated by the Mann-Whitney test.
  • Two dashed lines denote vitamin D deficiency and severe vitamin D deficiency.
  • The arrowheads and dots represent the outside value (>1.5× interquartile ranges) and far-out value (>3× interquartile ranges), respectively.
  • The horizontal lines represent the maximum and minimum values, except for the outside value and far-out value.

Fig. 1. Comparison of total 25-hydroxyvitamin D [25(OH)D], vitamin D binding protein (VDBP), and calculated bioavailable 25(OH)D in the three study groups.

Image

  • (A) The total 25(OH)D level in intensive care unit (ICU) patients (median, interquartile range: 11.65, 7.86-14.87 ng/mL) was significantly lower than that in healthy controls (18.25, 13.48-23.78 ng/mL) or in pregnant women (18.25, 13.98-25.24 ng/mL).
  • (B) The VDBP level in
    pregnant women (225.01, 130.24-422.92 μg/mL) was significantly higher, and the
    VDBP level in ICU patients (95.58, 61.15-167.34 μg/mL) was significantly lower
    than that in healthy controls (167.18, 105.99-257.70 μg/mL). (
  • C) The calculated bioavailable 25(OH)D levels of
    ICU patients (1.97, 1.48-3.15 ng/mL) and
    pregnant women (1.93, 1.03-3.41 ng/mL) were significantly lower than those in
    healthy controls (2.56, 1.95-4.22 ng/mL).
  • P values were calculated by the Mann-Whitney test.
  • Two dashed lines denote vitamin D deficiency and severe vitamin D deficiency.
  • The arrowheads and dots represent the outside value (>1.5? interquartile ranges) and far-out value (>3? interquartile ranges), respectively.
  • The horizontal lines represent maximum and minimum values, except for the outside value and far-out value.

Equations

Image

Attached files

ID Name Comment Uploaded Size Downloads
7328 Equations.jpg admin 13 Nov, 2016 10:47 29.07 Kb 283
7327 Compare pregnancy.jpg admin 13 Nov, 2016 10:43 42.53 Kb 282
7326 Compare.jpg admin 13 Nov, 2016 10:42 51.32 Kb 325
7325 VDP especially important during pregnancy.pdf PDF 2017 admin 13 Nov, 2016 10:42 319.78 Kb 214
See any problem with this page? Report it (FINALLY WORKS)