Georgia Prevention Institute, Department of Pediatrics, Georgia Health Sciences University, Augusta, GA 30912, USA.
Int J Obes (Lond). 2012 Jun;36(6):805-9. doi: 10.1038/ijo.2011.197. Epub 2011 Oct 11.
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.
本研究旨在探究维生素 D 补充是否能调节超重非裔美国人外周血单个核细胞（PBMC）端粒酶活性。
本研究采用了一项双盲、随机、安慰剂对照临床试验（#NCT01141192）。
非裔美国成年人被随机分配至安慰剂组或维生素 D 组（每月 60000IU[相当于 2000IU/天]口服维生素 D3 补充剂）。从 37 名受试者（安慰剂组 18 名，维生素 D 组 19 名）中均采集 PBMCs 样本，分别在基线和 16 周时采集。采用端粒重复扩增协议（TRAP）法测量 PBMC 端粒酶活性。
安慰剂组血清 25-羟维生素 D 水平从基线时的 40.7±15.7nmol/L 增加至试验后时的 48.1±17.5nmol/L（P=0.004），维生素 D 组从基线时的 35.4±11.3nmol/L 增加至试验后的 103.7±31.5nmol/L（P<0.0001）。维生素 D 组 PBMC 端粒酶活性从基线时的 1.56±0.29 吸光度读数单位（AU）增加至试验后时的 1.86±0.42 AU（P<0.0001），增加了 19.2%。校正年龄、性别和体重指数（BMI）后，该结果仍具有统计学意义（P=0.039）。安慰剂组 PBMC 端粒酶活性从基线时的 1.43±0.26 AU 增加至试验后时的 1.46±0.27 AU（P=0.157），未发生显著变化。
维生素 D 补充显著增加了超重非裔美国人 PBMC 端粒酶活性。我们的数据表明，维生素 D 可能改善端粒维持，防止细胞衰老，对抗肥胖引起的细胞衰老加速。
