Pérez-Bravo, FranciscoDuarte, LissetteArredondo-Olguín, MiguelIñiguez, GermánCastillo-Valenzuela, Oscar2021-12-102021-12-102021European Journal of Clinical Nutrition, Vol. 76, N° 6 (2021) p. 899-9011476-5640http://hdl.handle.net/20.500.12254/2090BACKGROUND: Vitamin D [25(OH)D] is essential for normal bone development and maintenance. Furthermore, its deficiency has been associated with obesity, cardiovascular diseases, insulin resistance, autoimmune diseases, and certain cancers. OBJECTIVE: To determine the incidence of serum 25(OH)D deficiency (<20 ng/ml) among apparently healthy Chilean children (4–14 years old) from three Chilean geographic areas during May–September 2018. MATERIALS AND METHODS: Serum 25(OH)D levels were measured by a competitive protein-binding ELISA assay in 1134 children, and correlations between serum 25(OH)D levels, BMI, and geographic area were calculated. Individuals were grouped according to their serum 25-hydroxyvitamin D levels (ng/ml): severe deficiency: <5; moderate deficiency: 5–10.9; mild deficiency: 11–20.9; insufficiency: 21–29.9 and sufficiency: 30–100. RESULTS: We found 80.4% of children had serum 25(OH)D deficiency, with 1.7% severe, 24.6% moderate, and 54.1% mild. In the three cities, the percentage of serum 25(OH)D deficit was increased when comparing overweight or obesity with a healthy weight. Additionally, an interaction effect was observed between geographic area, nutritional status, and serum 25(OH)D levels using the factorial ANOVA test (p = 0.038). In Antofagasta, there were more overweight children and also a higher percentage of children with VitD deficiency (<30 ng/ml) compared to Santiago or Concepción. CONCLUSION: This study revealed a high prevalence of serum 25(OH)D deficiency in children between 4 and 14 years old in Chile (80.4%) during May–September 2018. Obese and overweight children had the highest prevalence of serum 25(OH)D deficiency.enAtribución-NoComercial-CompartirIgual 3.0 Chile (CC BY-NC-SA 3.0 CL)Vitamin D status25-hydroxyvitamin Dhealthy childrenHealthy childrenAdolescentsVitamin D 33 deficiencySun exposureArtículohttps://orcid.org/0000-0002-4411-8655https://doi.org/10.1038/s41430-021-01043-9