In the 120 children with growing pains, vitamin D insufficiency was noted in 104 (86.6%). Following vitamin D supplementation, the mean 25(OH)D levels increased from 13.4 ± 7.2 to 44.5 ± 16.4 ng/ml, the mean pain VAS score decreased from 6.8 ± 1.9 to 2.9 ± 2.5 cm (a mean reduction of -3.8 ± 2.1, p<0.001) and the difference was statistically significant.