Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital, Tage Hansens Gade 2, DK, Aarhus 8000, Denmark.
Nutrients. 2013 Sep 5;5(9):3470-80. doi: 10.3390/nu5093470.
Use of hormonal contraceptives (HC) may influence total plasma concentrations of vitamin D metabolites. A likely cause is an increased synthesis of vitamin D binding protein (VDBP). Discrepant results are reported on whether the use of HC affects free concentrations of vitamin D metabolites.
In a cross-sectional study, plasma concentrations of vitamin D metabolites, VDBP, and the calculated free vitamin D index in users and non-users of HC were compared and markers of calcium and bone metabolism investigated.
75 Caucasian women aged 25-35 years were included during winter season. Compared with non-users (n = 23), users of HC (n = 52) had significantly higher plasma concentrations of 25-hydroxyvitamin D (25OHD) (median 84 interquartile range: [67-111] vs. 70 [47-83] nmol/L, p = 0.01), 1,25-dihydroxyvitamin D (1,25(OH)2D) (198 [163-241] vs. 158 [123-183] pmol/L, p = 0.01) and VDBP (358 [260-432] vs. 271 [179-302] µg/mL, p < 0.001). However, the calculated free indices (FI-25OHD and FI-1,25(OH)2D) were not significantly different between groups (p > 0.10). There were no significant differences in indices of calcium homeostasis (plasma concentrations of calcium, parathyroid hormone, and calcitonin, p > 0.21) or bone metabolism (plasma bone specific alkaline phosphatase, osteocalcin, and urinary NTX/creatinine ratio) between groups.
Use of HC is associated with 13%-25% higher concentrations of total vitamin D metabolites and VDBP. This however is not reflected in indices of calcium or bone metabolism. Use of HC should be considered in the interpretation of plasma concentrations vitamin D metabolites.
在一项横断面研究中，比较了使用和不使用激素避孕药（HC）的患者的维生素 D 代谢物、VDBP 血浆浓度和计算的游离维生素 D 指数，并研究了钙和骨代谢的标志物。
在冬季，纳入了 75 名年龄在 25-35 岁的白种人女性。与非使用者（n=23）相比，HC 使用者（n=52）的 25-羟维生素 D（25OHD）（中位数 84 四分位距：[67-111]与 70 [47-83] nmol/L，p=0.01）、1,25-二羟维生素 D（1,25（OH）2D）（198 [163-241]与 158 [123-183] pmol/L，p=0.01）和 VDBP（358 [260-432]与 271 [179-302] µg/mL，p < 0.001）的血浆浓度显著更高。然而，两组之间的计算游离指数（FI-25OHD 和 FI-1,25（OH）2D）没有显著差异（p>0.10）。两组之间钙稳态指数（血浆钙、甲状旁腺激素和降钙素浓度）或骨代谢指数（血浆骨特异性碱性磷酸酶、骨钙素和尿 NTX/肌酐比值）均无显著差异（p>0.21）。
使用 HC 与总维生素 D 代谢物和 VDBP 浓度升高 13%-25%相关。然而，这并没有反映在钙或骨代谢的指数中。在解释维生素 D 代谢物的血浆浓度时，应考虑 HC 的使用。
