Turkey, especially its eastern part, has been accepted as endemic for vitamin D deficiency rickets (VDDR). In a study performed by our team in the region in 1998, the incidence of VDDR was 6.09% in children aged between 0-3 years. In 2005, the Ministry of Health initiated a free vitamin D supplementation campaign nationwide for every infant to eradicate VDDR. In this study, we aimed to investigate the prevalence of VDDR in children aged between 0-3 years in order to evaluate the effectiveness of this campaign. Between March 2007 and February 2008, 39,133 children aged between 0-3 years who were brought to different pediatric outpatient clinics in Erzurum, Turkey, were examined for VDDR. VDDR diagnosis was made by radiological and biochemical findings in the cases who were initially suspected of having clinical VDDR. During a one-year period, 39 (0.099%) of the 39,133 patients were diagnosed with VDDR. None of the cases with rickets was taking vitamin D supplementation. The most frequent physical findings were rachitic rosary, enlargement of the wrists, and craniotabes. The laboratory findings of the cases were compatible with VDDR; serum calcium (Ca) 7.5 +/- 1.9 mg/dL, PO4 4.4 +/- 1.3 mg/dL, alkaline phosphatase (ALP) 1,341 +/- 823, 25-hydroxyvitamin D (25 (OH) D) 5.8 +/- 2.9 ng/mL, intact parathyroid hormone (iPTH) 240 +/- 106 pg/mL. It was concluded that, although VDDR has been a continuing childhood health problem, a nationwide free vitamin D supplementation campaign initiated by the government appeared to be effective in eliminating VDDR.