to analyze the prevalence of vitamin D deficiency throughout a natural year in a pediatric population with normal nutrition status. cross sectional clinical and analytical study (calcium, phosphorus, alkaline phosphatase, calcidiol and parathyroid hormone) in 413 caucasian individuals (aged 3.1 to 15.4 years): 227 school children (96 males and 131 females) and 186 adolescents (94 males and 92 females), all of them in a normal nutrition status, during the year 2014. Vitamin D deficiency was defined according to the United States Endocrine Society guidelines. calcidiol levels were lower during spring (25.96 ± 6.64 ng/ml) and reached its maximum level in summer (35.33 ± 7.51 ng/ml); PTH levels were lower in summer (27.13 ± 7.89 pg/ml) and reached maximum level in autumn (34.73 ± 15.38 pg/ml). Vitamin D deficiency prevalence was 14.3% in summer and 75.3% in spring. PTH levels were compatible with secondary hyperparathyroidism in 8 individuals (1.9%). There was a negative correlation between calcidol and PTH levels (p < 0.01). There was not a correlation between body mass index (BMI) and calcidiol. the pediatric population in normal nutrition status shows a high prevalence of vitamin D deficiency during the months of autumn and winter and, especially, in spring; the addition of vitamin supplements and/ or an increase in the ingestion of their natural dietary sources should be considered.