Vitamin D-Binding Protein in Healthy Pre- and Postmenopausal Women: Relationship with Estradiol Concentrations

Abstract

Objective To examine the relationship between endogenous serum estradiol and vitamin D–binding protein (DBP) and total, free, and bioavailable 25-hydroxyvitamin D (25OHD) concentrations in pre- and postmenopausal women. Methods In 165 healthy women (ages, 26 to 75 years) not taking any form of exogenous estrogen, the serum concentrations of estradiol, 25OHD, DBP, parathyroid hormone, and albumin were measured. Free and bioavailable 25OHD (free + albumin-bound) levels were calculated from total 25OHD, DBP, and serum albumin levels. Results Premenopausal women had higher serum 25OHD (31.5 ± 7.9 ng/mL), DBP (45.3 ± 6.2 mg/dL), and estradiol (52.8 ± 35.0 pg/mL) levels than postmenopausal women (26.5 ± 4.9 ng/mL, 41.7 ± 5.7 mg/dL, and 12.9 ± 4.9 pg/mL), respectively. In addition, the calculated free and bioavailable 25OHD levels were higher in pre- than postmenopausal women (P<.05). Serum estradiol correlated with DBP (r = 0.22; P<.01) and total 25OHD (r = 0.27; P<.01). In multivariate regression models (with or without serum 25OHD), estradiol was independently associated with DBP (P<.05). Conclusion Lower estradiol level is one of the factors that contribute to lower DBP levels in older women. Our data indicate that besides well-known factors such as age, gender, and race, serum estradiol concentrations are also a physiologic predictor of DBP concentration.

Serum vitamin D and sex hormones levels in men and women: The Multi-Ethnic Study of Atherosclerosis (MESA)

“…A prior study found that pre-menopausal women had higher levels of total 25(OH)D, vitamin D binding protein, and calculated free and bioavailable 25(OH)D compared to postmenopausal women, and that serum E2 levels correlated with vitamin D binding protein. [32] Thus, associations between vitamin D and E2 might be more clinically meaningful in pre-menopausal women, but we were unable to test for that in our cohort.…”

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

“…Fourth, there were statistically significant differences in age, gender, and albumin levels among our groups (Table 1). Because young age and female sex are associated with high VDBP levels [2324] and the bioavailable 25(OH)D calculation includes the albumin level, our results on the differences in VDBP levels and in the calculated bioavailable 25(OH)D levels among the groups could be affected by these differences in characteristics of the study subjects. Nonetheless, the calculated bioavailable 25(OH)D may reflect the status of VDBP levels and the albumin levels in each patient; therefore, calculated bioavailable 25(OH)D could be used to assess vitamin D status accurately in the patients with altered VDBP levels or albumin levels.…”

Serum Proteomic Analysis Reveals Vitamin D-Binding Protein (VDBP) as a Potential Biomarker for Low Bone Mineral Density in Mexican Postmenopausal Women

“…We conducted a comprehensive literature review in the Medline database for these six proteins, to investigate their relevance regarding bone metabolism and their potential use as biomarkers. The proteins GSN, CP, and VDBP have previously been related to bone metabolism and proposed as potential biomarkers to identify BMD variation [21][22][23][24][25][26][27]. Additionally, we included other proteins with a role in bone remodeling or metabolism, as described in previous studies, such as alpha-2-S-glycoprotein (AHSG) [28,29], alpha-1-antitrypsin (SERPINA1) [30], and haptoglobin (HP) [31].…”