Increased telomerase activity and vitamin D supplementation in overweight African Americans

Int J Obes (Lond). 2012 Jun;36(6):805-9. doi: 10.1038/ijo.2011.197. Epub 2011 Oct 11.


Objective: We aimed to investigate whether vitamin D supplementation modulates peripheral blood mononuclear cell (PBMC) telomerase activity in overweight African Americans.

Design: A double blind, randomized and placebo-controlled clinical trial (#NCT01141192) was recently conducted.

Subjects and methods: 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.

Results: 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).

Conclusion: 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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • African Americans*
  • Analysis of Variance
  • Cholecalciferol / therapeutic use*
  • Cross-Sectional Studies
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Leukocytes, Mononuclear / enzymology*
  • Male
  • Middle Aged
  • Obesity / blood*
  • Obesity / diet therapy
  • Obesity / enzymology
  • Telomerase / metabolism*
  • Treatment Outcome
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood


  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human
  • Vitamin D
  • Cholecalciferol
  • 25-hydroxyvitamin D
  • Telomerase

Associated data