Vitamin D Binding Protein Impact on 25-Hydroxyvitamin D Levels under Different Physiologic and Pathologic Conditions. (28th April 2014)

• Record Type: Journal Article
• Authors: Yousefzadeh, Pegah; Shapses, Sue A.; Wang, Xiangbing
• Other Names: Xie Zhongjian Academic Editor.
• Is Part Of: International journal of endocrinology. Volume 2014(2014)
• Publication Date: 2014-04-28
• Subjects: Endocrinology -- Periodicals; Endocrinology; Endocrinology -- Periodicals; Endocrine System Diseases -- Periodicals; Periodicals; 616.4
• DOI: 10.1155/2014/981581
• Languages: English
• ISSNs: 1687-8337

Abstract

Abstract : There is a high prevalence of vitamin D deficiency worldwide, but how to define vitamin D deficiency is controversial. Currently, the plasma concentration of total 25-hydroxyvitamin D [25(OH)D] is considered an indicator of vitamin D status. The free hormone hypothesis states that protein-bound hormones are inactive while unbound hormones are free to exert biological activity. The majority of circulating 25(OH)D and 1, 25(OH)2 D is tightly bound to vitamin D binding protein (DBP), 10–15% is bound to albumin, and less than 1% of circulating vitamin D exists in an unbound form. While DBP is relatively stable in most healthy populations, a recent study showed that there are gene polymorphisms associated with race and ethnicity that could alter DBP levels and binding affinity. Furthermore, in some clinical situations, total vitamin D levels are altered and knowing whether DBP is also altered may have treatment implications. The aim of this review is to assess DBP concentration in different physiological and pathophysiological conditions. We suggest that DBP should be considered in the interpretation of 25(OH)D levels.