TY  - JOUR
TI  - Is Bioavailable Vitamin D Better Than Total Vitamin D to Evaluate
Vitamin D Status in Obese Children?
AB  - Objective: Free hormones are biologically more active in target tissues. Thus, measurement of vitamin D taking into account
bioavailability and free vitamin D may be preferable, especially when evidence is contradictory, as in obese children. In order to assess
bioavailablity and free vitamin D, using a previously reported formula, vitamin D-binding protein (VDBP) level was measured and VDBP
polymorphisms were also evaluated because of variations in binding affinity.
Methods: Eighty-four obese and 78 healthy children were included. Anthropometry, calcium, phosphorus, alkaline-phosphatase,
parathyroid hormone (PTH), 25 hydroxyvitamin D [25(OH)D], bioavailable-free vitamin D, and VDBP concentration and polymorphism
were evaluated in the whole group.
Results: Obese girls had significantly higher PTH than normal weight girls (p=0.001). Regardless of gender, obese children had
significantly higher concentrations of VDBP (p=0.008) and PTH (p=0.002). When samples taken in winter were analyzed, PTH and
VDBP were found to be higher and bioavailable and free vitamin D lower in the obese group. There was no difference in terms of total
vitamin D between groups during the winter season.
Conclusion: While total, free, and bioavailable vitamin D in the obese group was similar to the control group in autumn, free and
bioavailable vitamin D in the winter was lower in the obese than the control group. In addition, PTH was higher in the obese group in
both autumn and winter. Therefore, more research is needed to evaluate the variability of free and bioavailable vitamin D according to
body habitus, season and the effect any differences may have.
AU  - Gülbahar, Özlem
AU  - aycan, zehra
AU  - Özalkak, Şervan
AU  - Karacan Küçükali, Gülin
AU  - SAVAS ERDEVE, SENAY
AU  - DAGLI, HASAN
AU  - Ceylaner, Serdar
DO  - 10.4274/jcrpe.galenos.2020.2021.0230
PY  - 2021
JO  - Journal of Clinical Research in Pediatric Endocrinology
VL  - 13
IS  - 4
SN  - 1308-5727
SP  - 391
EP  - 399
DB  - TRDizin
UR  - http://search/yayin/detay/521127
ER  -