3-,9- and 15-year-old children were studied in autumn in order to evaluate their serum 25-hydroxy-vitamin D (25-OH-D) concentration and their vitamin D intake. The 25-OH-D was significantly lower in the 15-year-old than in the other children, but it was satisfactory in all groups as compared to the 25-OH-D of healthy, young adults. The mean dietary vitamin D intake as well as the mean total vitamin D intake including supplements was low in all groups of children. With a vitamin D intake as low as in this study, every house-bound child would be at risk of vitamin D deficiency.