VITAMIN-E SUPPLEMENTATION AND IN-VIVO IMMUNE-RESPONSE IN HEALTHY ELDERLY SUBJECTS - A RANDOMIZED CONTROLLED TRIAL

Objective.-To determine whether long-term supplementation with vitamin E enhances in vivo, clinically relevant measures of cell-mediated imm unity in healthy elderly subjects. Design.-Randomized, double-blind, p lacebo-controlled intervention study. Setting and Participants.-A tota l of 88 free-living, healthy subjects at least 65 years of age. Interv ention.-Subjects were randomly assigned to a placebo group or to group s consuming 60, 200, or 800 mg/d of vitamin E for 235 days. Main Outco me Measures.-Delayed-type hypersensitivity skin response (DTH); antibo dy response to hepatitis B, tetanus and diphtheria, and pneumococcal v accines; and autoantibodies to DNA and thyroglobulin were assessed bef ore and after supplementation. Results.-Supplementation with vitamin E for 4 months improved certain clinically relevant indexes of cell-med iated immunity in healthy elderly. Subjects consuming 200 mg/d of vita min E had a 65% increase in DTH and a 6-fold increase in antibody tite r to hepatitis B compared with placebo (17% and S-fold, respectively), 60-mg/d (41% and 3-fold, respectively), and 800-mg/d (49% and 2.5-fol d, respectively) groups. The 200-mg/d group also had a significant inc rease in antibody titer to tetanus vaccine. Subjects in the upper tert ile of serum a-tocopherol (vitamin E) concentration (>48.4 mu mol/l [2 .08 mg/dL]) after supplementation had higher antibody response to hepa titis B and DTH. Vitamin E supplementation had no effect on antibody t iter to diphtheria and did not affect immunoglobulin levels or levels of T and B cells. No significant effect of vitamin E supplementation o n autoantibody levels was observed. Conclusions.-Our results indicate that a level of vitamin E greater than currently recommended enhances certain clinically relevant in vivo indexes of T-cell-mediated functio n in healthy elderly persons. No adverse effects were observed with vi tamin E supplementation.