Biomaterial Database

Free 25-Hydroxyvitamin D: Impact of Vitamin D Binding Protein Assays on Racial-Genotypic Associations. 2016

Carrie M Nielson, and Kerry S Jones, and Rene F Chun, and Jon M Jacobs, and Ying Wang, and Martin Hewison, and John S Adams, and Christine M Swanson, and Christine G Lee, and Dirk Vanderschueren, and Steven Pauwels, and Ann Prentice, and Richard D Smith, and Tujin Shi, and Yuqian Gao, and Athena A Schepmoes, and Joseph M Zmuda, and Jodi Lapidus, and Jane A Cauley, and Roger Bouillon, and Inez Schoenmakers, and Eric S Orwoll, and

Bone & Mineral Unit (C.M.N., Y.W., C.M.S., E.S.O.), Oregon Health & Science University, Portland, Oregon 97239; School of Public Health (C.M.N., J.L.), Oregon Health & Science University, Portland, Oregon 97239; Medical Research Council Human Nutrition Research (K.S.J., A.P., I.S.), Cambridge, UK CB1 9NL; Department of Orthopedics (R.F.C.), University of California, Los Angeles, California 90095; Pacific Northwest National Laboratory (J.M.J., R.D.S., T.S., Y.G., A.A.S.), Richland, Washington 99354; Institute of Metabolism and Systems Research (M.H.), University of Birmingham, Birmingham, UK B15 2TT; University of California (J.S.A.), Los Angeles, California 90095; School of Medicine (C.M.S., C.G.L., E.S.O.), Oregon Health & Science University, Portland, Oregon 97239; Portland Veterans Affairs Medical Center (C.G.L.), Oregon 97239; Laboratory of Diagnostic Medicine (D.V.), KU Leuven, 3000 Belgium; Laboratory of Clinical and Experimental Endocrinology (D.V., R.B.), KU Leuven, 3000 Belgium; Department of Cardiovascular Sciences (S.P.), KU Leuven, Belgium 3000; Department of Laboratory Medicine (S.P.), University Hospitals Leuven, 3000 Belgium; MRC Keneba (A.P.), Keneba, The Gambia; and Department of Epidemiology (J.M.Z., J.A.C.), University of Pittsburgh, Pennsylvania 15261.

Total 25-hydroxyvitamin D (25OHD) is a marker of vitamin D status and is lower in African Americans than in whites. Whether this difference holds for free 25OHOD (f25OHD) is unclear, considering reported genetic-racial differences in vitamin D binding protein (DBP) used to calculate f25OHD. Our objective was to assess racial-geographic differences in f25OHD and to understand inconsistencies in racial associations with DBP and calculated f25OHD. This study used a cross-sectional design. The general community in the United States, United Kingdom, and The Gambia were included in this study. Men in Osteoporotic Fractures in Men and Medical Research Council studies (N = 1057) were included. Total 25OHD concentration, race, and DBP (GC) genotype exposures were included. Directly measured f25OHD, DBP assessed by proteomics, monoclonal and polyclonal immunoassays, and calculated f25OHD were the outcome measures. Total 25OHD correlated strongly with directly measured f25OHD (Spearman r = 0.84). Measured by monoclonal assay, mean DBP in African-ancestry subjects was approximately 50% lower than in whites, whereas DBP measured by polyclonal DBP antibodies or proteomic methods was not lower in African-ancestry. Calculated f25OHD (using polyclonal DBP assays) correlated strongly with directly measured f25OHD (r = 0.80-0.83). Free 25OHD, measured or calculated from polyclonal DBP assays, reflected total 25OHD concentration irrespective of race and was lower in African Americans than in US whites. Previously reported racial differences in DBP concentration are likely from monoclonal assay bias, as there was no racial difference in DBP concentration by other methods. This confirms the poor vitamin D status of many African-Americans and the utility of total 25OHD in assessing vitamin D in the general population.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D003430	Cross-Sectional Studies	Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.	Disease Frequency Surveys,Prevalence Studies,Analysis, Cross-Sectional,Cross Sectional Analysis,Cross-Sectional Survey,Surveys, Disease Frequency,Analyses, Cross Sectional,Analyses, Cross-Sectional,Analysis, Cross Sectional,Cross Sectional Analyses,Cross Sectional Studies,Cross Sectional Survey,Cross-Sectional Analyses,Cross-Sectional Analysis,Cross-Sectional Study,Cross-Sectional Surveys,Disease Frequency Survey,Prevalence Study,Studies, Cross-Sectional,Studies, Prevalence,Study, Cross-Sectional,Study, Prevalence,Survey, Cross-Sectional,Survey, Disease Frequency,Surveys, Cross-Sectional
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D014807	Vitamin D	A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
D014809	Vitamin D-Binding Protein	An alpha-globulin found in the plasma of man and other vertebrates. It is apparently synthesized in the liver and carries vitamin D and its metabolites through the circulation and mediates the response of tissue. It is also known as group-specific component (Gc). Gc subtypes are used to determine specific phenotypes and gene frequencies. These data are employed in the classification of population groups, paternity investigations, and in forensic medicine.	Group-Specific Component Globulin,Vitamin D-Binding Globulin,25-HCC-Binding Protein,25-Hydroxycholecalciferol-Binding Protein,25-Hydroxyvitamin D-Binding Protein,Calciferol-Binding Protein,Gc Globulin,Transcalciferin,25 HCC Binding Protein,25 Hydroxycholecalciferol Binding Protein,25 Hydroxyvitamin D Binding Protein,Calciferol Binding Protein,Component Globulin, Group-Specific,Globulin, Gc,Globulin, Group-Specific Component,Globulin, Vitamin D-Binding,Group Specific Component Globulin,Vitamin D Binding Globulin,Vitamin D Binding Protein
D044383	Black People	Persons having origins in any of the black racial groups of AFRICA. Note that OMB category BLACK OR AFRICAN AMERICAN is available for the United States population groups. Race and ethnicity terms, as used in the federal government, are self-identified social construct and may include terms outdated and offensive in MeSH to assist users who are interested in retrieving comprehensive search results for studies such as in longitudinal studies.	African Continental Ancestry Group,Black Person,Negroid Race,Black Peoples,Black Persons,Negroid Races,People, Black,Person, Black,Persons, Black,Race, Negroid
D044465	White People	Persons having origins in any of the white racial groups of Europe, the Middle East, or North Africa. Note that OMB category WHITE is available for the United States population groups. Race and ethnicity terms, as used in the federal government, are self-identified social construct and may include terms outdated and offensive in MeSH to assist users who are interested in retrieving comprehensive search results for studies such as in longitudinal studies.	European Continental Ancestry Group,White Person,Caucasian Race,Caucasoid Race,Caucasian Races,Caucasoid Races,People, White,Person, White,Race, Caucasian,Race, Caucasoid,White Peoples,White Persons