In Reply: In response to Dr Krul and colleagues, the concentration of vitamin E did not differ significantly between the 698 persons in our study sample (mean, 30.6 μmol/L [to convert to μg/uL, divide by 23.22]) and the 457 persons who were excluded (mean, 29.2 μmol/L; P = .15) after adjustment for age, which differed between the 2 groups. Among the subset of excluded persons who were lost to follow-up (n = 214), the mean age was 76.5 years and the mean concentration of vitamin E was 30.2 μmol/L. Although the age of these persons was significantly older than that in our study sample (P < .001), the concentration of vitamin E did not differ between the 2 groups (adjusted for age, P = .82).
Bartali B, Ferrucci L, Gill T. Vitamin E Concentration and Physical Decline in Older Persons—Reply. JAMA. 2008;299(17):2021. doi:10.1001/jama.299.17.2021-b