title: Effects of Genetic and Nongenetic Factors on Total and Bioavailable 25(OH)D Responses to Vitamin D Supplementation.
abstract: Little is known about how genetic and nongenetic factors modify responses of vitamin D supplementation in nonwhite populations.
  
  
  
  To investigate factors modifying 25-hydroxyvitamin D [25(OH)D] and bioavailable 25(OH)D [25(OH)DBio] responses after vitamin D3 supplementation.
  
  
  
  In this 20-week, randomized, double-blinded, placebo-controlled trial, 448 Chinese with vitamin D deficiency received 2000 IU/d vitamin D3 or placebo.
  
  
  
  Serum 25(OH)D, vitamin D-binding protein (VDBP), parathyroid hormone (PTH) and calcium were measured, and 25(OH)DBio was calculated based on VDBP levels. Six common polymorphisms in vitamin D metabolism genes were genotyped.
  
  
  
  Between-arm net changes were +30.6 ± 1.7 nmol/L for 25(OH)D, +2.7 ± 0.2 nmol/L for 25(OH)DBio, and -5.2 ± 1.2 pg/mL for PTH, corresponding to 70% [95% confidence interval (CI), 62.8% to 77.2%] net reversion rate for vitamin D deficiency at week 20 (P < 0.001). Only 25(OH)DBio change was positively associated with calcium change (P < 0.001). Genetic factors (GC-rs4588/GC-rs7041, VDR-rs2228570, and CYP2R1-rs10741657; P ≤ 0.04) showed stronger influences on 25(OH)D or 25(OH)DBio responses than nongenetic factors, including baseline value, body mass index, and sex. An inverse association of PTH-25(OH)D was demonstrated only at 25(OH)D of <50.8 (95% CI, 43.6 to 59.0) nmol/L.
  
  
  
  Supplemented 2000 IU/d vitamin D3 raised 25(OH)D and 25(OH)DBio but was unable to correct deficiency in 25% of Chinese participants, which might be partially attributed to the effect of genetic modification. More studies are needed to elucidate appropriate vitamin D recommendations for Asians and the potential clinical implications of 25(OH)DBio.
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Pang
authors: P
authors: Yao
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Liang
authors: L
authors: Sun
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Ling
authors: L
authors: Lu
authors: Department of Nutrition and Food Hygiene, School of Public Health, Xinjiang Medical University, Urumqi 830011, China.
authors: Hong
authors: H
authors: Ding
authors: Huadong Hospital Affiliated with Fudan University, Shanghai 200040, China.
authors: Xiafei
authors: X
authors: Chen
authors: Huadong Hospital Affiliated with Fudan University, Shanghai 200040, China.
authors: Lixin
authors: L
authors: Tang
authors: High School Affiliated to Fudan University, Shanghai 200433, China; and.
authors: Xinming
authors: X
authors: Xu
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Gang
authors: G
authors: Liu
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Yao
authors: Y
authors: Hu
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Yiwei
authors: Y
authors: Ma
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Feijie
authors: F
authors: Wang
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Qianlu
authors: Q
authors: Jin
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: He
authors: H
authors: Zheng
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Huiyong
authors: H
authors: Yin
authors: Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and University of the Chinese Academy of Sciences, Shanghai 200031, China.
authors: Rong
authors: R
authors: Zeng
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Yan
authors: Y
authors: Chen
authors: Departments of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts 02115.
authors: Frank B
authors: FB
authors: Hu
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Huaixing
authors: H
authors: Li
authors: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, and.
authors: Xu
authors: X
authors: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000188:drug therapy / Q000235:genetics*; D014809:Vitamin D-Binding Protein / Q000097:blood / Q000235:genetics*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium