Vitamin C and Growth-Reply

We agree with Jukes thatour data provide no overall evidence for a treatment effect of pharmacologic doses of vitamin C on growth and clearly stated this in our article. However, we did observe significant heterogeneity by analysis of variance in the response to vitamin C among treatment groups (P<.05) and, as reported, found an apparent effect on growth in the male twins receiving 500 mg per day (P<.01) when individual group means were compared. The actual measurements are given in Table 2, where it can be seen that six of the seven treated male twins grew more than their co-twins, while in the seventh pair there was no difference in growth. We disagree with Jukes' statement that "an opposite conclusion could just as easily... be drawn from the 1,000 mg/day figures for male twins," since the mean difference for this group was less than twice