title: Genetic and environmental predictors of serum 25-hydroxyvitamin D concentrations among middle-aged and elderly Chinese in Singapore.
abstract: Vitamin D is known for maintaining Ca homeostasis and bone structure, and may also decrease susceptibility to chronic and infectious diseases. However, data on vitamin D status and its predictors among Southeast Asian populations are limited. We evaluated the distribution and determinants (genetic and environmental) of serum 25-hydroxyvitamin D (25(OH)D) concentrations among 504 middle-aged and elderly participants (aged 45-74 years) in the Singapore Chinese Health Study. Data on dietary and other lifestyle factors were collected by trained interviewers. Serum 25(OH)D concentrations and genetic polymorphisms in vitamin D metabolism pathway enzymes (cytochrome P450 (CYP) 2R1, 3A4, 27B1, 24A1; vitamin D binding protein (also known as group-specific component, GC); and vitamin D receptor) were measured using stored biospecimens. Mean 25(OH)D concentration was 68·8 nmol/l. Serum 25(OH)D concentrations were positively associated with dietary vitamin D intake, and inversely associated with hours spent sitting at work. BMI was not associated with 25(OH)D concentrations. CYP2R1 rs10741657, rs12794714, rs1993116; CYP3A4 rs2242480; and GC rs4588, rs7041, rs16847015, rs2298849 were statistically significantly associated with 25(OH)D concentrations. Individuals with the Gc2-2 haplotype (rs4588AA/rs7041TT) had statistically significantly lower 25(OH)D concentrations compared to all other Gc haplotypes (P-trend < 0·001). The majority of participants (86 %) had 25(OH)D concentrations ≥ 50 nmol/l, which is consistent with the 2011 Institute of Medicine (US) recommendation for bone health, and 32 % had concentrations of ≥ 75 nmol/l that are thought to be required for broader health effects. Dietary vitamin D intake, hours spent indoors at work and genetic variation in CYP2R1, CYP3A4 and GC are significant predictors of 25(OH)D concentrations among Singapore Chinese.
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 1300 South 2nd Street, Suite 300, Minneapolis, MN 55455, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Robien
authors.affiliation: Environmental and Radiological Health Sciences, Colorado State University, 148B EH Building, 1681 Campus Delivery, Fort Collins, CO 80523-1681, USA.
authors.forename: Lesley M
authors.initials: LM
authors.lastname: Butler
authors.affiliation: University of Pittsburgh Cancer Institute, UPMC Cancer Pavillion, Suite 4C-464, 5150 Center Avenue, Pittsburgh, PA 15232, USA.
authors.forename: Renwei
authors.initials: R
authors.lastname: Wang
authors.affiliation: Biomedical Genomics Center, University of Minnesota, MMC 501 Mayo, 8501, 420 Delaware Street, SE, Minneapolis, MN 55455, USA.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Beckman
authors.affiliation: Biomedical Genomics Center, University of Minnesota, MMC 501 Mayo, 8501, 420 Delaware Street, SE, Minneapolis, MN 55455, USA.
authors.forename: Dinesha
authors.initials: D
authors.lastname: Walek
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, MD3, 16 Medical Drive, Singapore 117597, Singapore.
authors.forename: Woon-Puay
authors.initials: WP
authors.lastname: Koh
authors.affiliation: University of Pittsburgh Cancer Institute, UPMC Cancer Pavillion, Suite 4C-464, 5150 Center Avenue, Pittsburgh, PA 15232, USA.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Yuan
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000368:Aged; D002112:Calcifediol / Q000097:blood; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics* / Q000378:metabolism; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D051544:Cytochrome P-450 CYP3A / Q000235:genetics* / Q000378:metabolism; D000072467:Cytochrome P450 Family 2; D004032:Diet / Q000009:adverse effects*; D005260:Female; D059647:Gene-Environment Interaction; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D020641:Polymorphism, Single Nucleotide; D057185:Sedentary Behavior; D012846:Singapore / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D014809:Vitamin D-Binding Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: D014809:Vitamin D-Binding Protein; D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D051544:Cytochrome P-450 CYP3A; D000072467:Cytochrome P450 Family 2; C506833:CYP2R1 protein, human; C510163:CYP3A4 protein, human; D053493:Cholestanetriol 26-Monooxygenase; D002112:Calcifediol