A cross-sectional study was carried out of 412 healthy and 226 chronically malnourished children in Recife, Brazil. Anthropometric measurements, x-rays of hands and wrists, and biochemical data related to skeletal growth were obtained. Levels of plasma 25 hydroxyvitamin D were measured in both groups of children and both showed higher concentrations than those reported for normal European children. The high levels of 25 hydroxyvitamin D found in these two groups of Brazilian children are probably the result of the intense solar radiation in this part of Brazil and argue against the diet being an important source of vitamin D in poorly nourished children. Some bone abnormalities were seen in the underprivileged group of children but in view of our findings these were more likely to be a result of protein-energy malnutrition than rickets.