Comparison of serum levels of vitamin D and vitamin D-binding protein in normal, osteopenic and osteoporotic postmenopausal women.

Objective: To compare the serum levels of vitamin D, vitamin D binding protein (VDBP) calcium and phosphate in normal, osteopenic and osteoporotic postmenopausal women categorized on the basis of bone mineral density (BMD) scores.

Methods: A cross sectional study carried out from May 2017 to August 2018. BMD measured by Dual energy X-ray Absorptiometry categorized women (aged 20- 70 years) into normal (n=37) (T score ≥ -1.0) osteopenic (n=25) (-2.5< T score, < -1) and osteoporotic (n= 26) (T score < -2.5) according to WHO classification. Serum concentrations of vitamin D, VDBP, calcium, phosphate analyzed by enzyme linked immunosorbent assay were compared by Analysis of Variance.

Results: In normal females higher levels of vitamin D and VDBP were observed [15.82 (8 - 69.18), 469.9 (269.57 - 875.55)] vs. osteopenic [(7.45 (4.66 - 15.1), 296.05 (232.58 - 420.23)] and osteoporotic women [(7.25 (3.97 - 17.49), 272.94 (202.23 - 351.24)]; [median interquartile range]; p value < 0.0001.

Conclusion: Vitamin D and VDBP are linked with bone health and estimation of VDBP appears to be a valuable tool for the assessment of increased bone loss and possible risks of bone fractures especially in postmenopausal women.