The long-term benefits of early childhood supplementation and the extent to which catch-up growth occurs following linear growth retardation remain controversial. Stunted children (height-for-age < -2 SD of NCHS references, n = 122) recruited from a survey of poor neighborhoods in Kingston, Jamaica, participated in a 2-yr randomized, controlled trial of supplementation beginning at ages 9-24 mo. A group of 32 non-stunted children from the same neighborhoods was also followed. Four years after the intervention ended, when children were 7 to 8 y old, there were no effects of supplementation on any anthropometric measure. From the end of the trial until follow-up, the children who had been supplemented gained 1.2 cm less (P < 0.05) than the non-supplemented children, approximately the same amount as they had gained during the trial compared with the non-supplemented children. After adjustment for regression to the mean, the height-for-age of stunted children (supplemented and non-supplemented combined) increased from enrollment to follow-up by 0.31 Z-score (95% CI 0.17, 0.46). The height-for-age of the non-stunted children also increased (0.96 Z-score; 95% CI 0.70, 1.22). Our results suggest that some catch-up growth is possible even when children remain in poor environments. Long-term benefits of supplementation to growth may not be achieved when intervention begins after age 12 mo in children who have already become undernourished.
