Increased telomerase activity and vitamin D supplementation in overweight African Americans

• DOI: 10.1038/ijo.2011.197
• Publication Date: 2011-10-11T10:05:56Z
• Authors: H Zhu; D Guo; K Li; J Pedersen-White; I S Stallmann-Jor...; Y Huang; S Parikh; K Liu; Y Dong
• Keywords: Adult; Glycated Hemoglobin; Male; 0301 basic medicine; 2. Zero hunger; Analysis of Variance; Middle Aged; 3. Good health; Black or African American; 03 medical and health sciences; Cross-Sectional Studies; Treatment Outcome; Double-Blind Method; Dietary Supplements; Leukocytes, Mononuclear; Humans; Female; Obesity; Vitamin D; Telomerase; Cholecalciferol

We aimed to investigate whether vitamin D supplementation modulates peripheral blood mononuclear cell (PBMC) telomerase activity in overweight African Americans.A double blind, randomized and placebo-controlled clinical trial (#NCT01141192) was recently conducted.African-American adults were randomly assigned to either the placebo, or the vitamin D group (60,000 IU per month (equivalent to ~2000 IU per day) oral vitamin D3 supplementation). Fresh PBMCs were collected from 37 subjects (18 in the placebo group and 19 in the vitamin D group), both at baseline and 16 weeks. PBMC telomerase activity was measured by the telomeric repeat amplification protocol.Serum 25 hydroxyvitamin D levels increased from 40.7±15.7 at baseline to 48.1±17.5 nmol l(-1) at posttest (P=0.004) in the placebo group, and from 35.4±11.3 at baseline to 103.7±31.5 nmol l(-1) at posttests (P<0.0001) in the vitamin D group. In the vitamin D group, PBMC telomerase activity increased by 19.2% from baseline (1.56±0.29 absorbance reading unit (AU)) to posttest (1.86±0.42 AU, P<0.0001). The significance persisted after controlling for age, sex and body mass index (P=0.039). PBMC telomerase activity in the placebo group did not change from baseline (1.43±0.26 AU) to posttest (1.46±0.27 AU, P=0.157).Vitamin D supplementation significantly increased PBMC telomerase activity in overweight African Americans. Our data suggest that vitamin D may improve telomere maintenance and prevent cell senescence and counteract obesity-induced acceleration of cellular aging.