Serum 25(OH)D and Lipid Levels in Chinese Obese and Normal Weight Males before and after Oral Vitamin D Supplementation

Objective To study the effect of oral vitamin D （VD） supplementation on VD status and serum lipid in Chinese obese and healthy normal-weight men. Methods Twenty-one obese men with their body mass index （BMI）〉28 kg/m2 served as an obese group and 22 healthy normal-weight men with their BMI〈24 kg/m2 served as a control group in this study. After they were given 50 000 IU of oral VD, once a week for 8 weeks, the serum 25-hydroxyvitamin D [25（OH）D] concentration was measured with an enzyme-immunoassay kit. Results After oral VD supplementation, the serum 25（OH）D concentration significantly increased from 46.1＋9.1 nmol/L to 116.7_＋20.3 nmol/L in the obese subjects （P〈O.01） and from 52.8_＋17.8 nmol/L to 181.3_＋30.2 nmol/L in the control ones （P=0.13）. The serum high-density lipoprotein cholesterol （HDL-C） level was reduced within the normal reference range in the obese group. However, no significant change was observed in the level of other serum lipids （triglycerides, total cholesterol, and low-density lipoprotein cholesterol） in either of the two groups. Conclusion The effect of high-dose oral VD supplementation is weaker on VD status in the obese group than in the control group. High-dose oral VD supplementation has no side effect on serum lipid level in obese and control groups.

Polymorphisms of the Vitamin D Receptor Gene and SexDifferential Associations with Lipid Profiles in Chinese Han Adults

Objective To explore the association of single nucleotide polymorphisms(SNPs)of the vitamin D receptor gene(VDR)with circulating lipids considering gender differences.Methods Of the Han Chinese adults recruited from a health examination center for inclusion in the study,the circulating lipids,25-hydroxyvitamin D(25OHD),and other parameters were measured.The VDR SNPs of Cdx2(rs11568820),Fok1(rs2228570),Apa1(rs7975232),and Taq1(rs731236)were genotyped with a qPCR test using blood DNA samples,and their associations with lipids were analyzed using logistic regression.Results In the female participants(n=236 with dyslipidemia and 888 without dyslipidemia),multiple genotype models of Fok1 indicated a positive correlation of B(not A)alleles with LDLC level(P<0.05).In the male participants(n=299 with dyslipidemia and 564 without dyslipidemia),the recessive model of Cdx2 and the additive and recessive models of Fok1 differed(P<0.05)between the HDLC-classified subgroups,respectively,and Fok1 BB and Cdx2 TT presented interactions with 25OHD in the negative associations with HDLC(P<0.05).Conclusion In the Chinese Han adults included in the study,the Fok1 B-allele of VDR was associated with higher LDLC in females,and the Fok1 B-allele and the Cdx2 T-allele of VDR were associated with lower HDLC in males.The interaction of VD and Fok1 BB or Cdx2 TT in males synergistically decreased HDLC levels.