Increased Plasma Concentrations of Vitamin D Metabolites and Vitamin D Binding Protein in Women Using Hormonal Contraceptives: A Cross-Sectional Study

Nutrients

Ulla K. Møller²  Susanna við Streym²  Lars T. Jensen³  Leif Mosekilde²  Inez Schoenmakers¹  Shailja Nigdikar¹ 

[1] MRC Human Nutrition Research, Cambridge CB1 9NL, UK; E-Mails:;Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital, Tage Hansens Gade 2, DK, Aarhus 8000, Denmark; E-Mails:;Department of Clinical Physiology, Glostrup University Hospital, Copenhagen DK-2900, Denmark; E-Mail:

关键词: hormonal contraceptives;    25hydroxyvitamin D;    1;    25-dihydroxyvitamin D;    vitamin D binding protein;    parathyroid hormone;    calcitonin;    bone turnover;    bone mineral density;   

DOI  :  10.3390/nu5093470

来源: mdpi

【 摘 要 】

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. Aim: 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. Results: 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. In conclusion: 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.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.