title: [Hypovitaminosis D and associated factors in 4-year old children in northern Spain].
abstract: BACKGROUND
  Vitamin D is an essential prohormone in calcium and phosphorus homeostasis. Recent studies show a high frequency of insufficiency/deficiency of vitamin D in the general population worldwide. Our objective was to estimate the prevalence of circulating vitamin D [25(OH)D3] deficiency and insufficiency in children and examine the associated factors.
  
  
  METHODS
  A total of 283 children, participants in the cohort INMA-Asturias, were studied. The 25(OH)D3 concentrations were quantified by high performance liquid chromatography. The prevalence of deficiency [25(OH)D3<20 ng/ml] and insufficiency [20-29.9 ng/ml] of vitamin D was estimated. Distribution of 25(OH)D3 for month of extraction of specimen, ingestion, and other factors were analysed.
  
  
  RESULTS
  The mean 25(OH)D3 was 20.1 ng/ml (range 2.7-49.8), with 8.8% ≥ 30 ng/ml, 38.5% from 20-20.9 ng/ml, and 52.7%<20 ng/ml. Seasonal variation was found, with lower values in winter. There was no relationship between plasma levels and intake of vitamin D (median 2.7μg/day, range 0.81-12.62), time outdoors (mean 3hours, range: 0:21-6:55), or BMI or gender, but there was one found with the mother's levels during gestation.
  
  
  CONCLUSIONS
  There is a high prevalence of vitamin D deficiency/insufficiency in children at 4 years. Solar exposure might not be enough in our region. Healthy children should be encouraged to follow adequate outdoor activities with associated sun exposure. Due the deficit of intake in childhood, recommendations are needed about a varied diet with vitamin D-containing foods in this age group, especially during the winter, and assessing the need of vitamin D supplementation in children at risk.
authors.affiliation: Servicio de Pediatría, Hospital San Agustín, Avilés, Asturias, España. Electronic address: crdehli@yahoo.es.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Rodríguez-Dehli
authors.affiliation: Servicio de Pediatría, Hospital San Agustín, Avilés, Asturias, España; CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, España.
authors.forename: Isolina
authors.initials: I
authors.lastname: Riaño-Galán
authors.affiliation: CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, España; IUOPA-Área de Medicina Preventiva y Salud Pública, Departamento de Medicina, Universidad de Oviedo, Oviedo, Asturias, España.
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández-Somoano
authors.affiliation: CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, España.
authors.forename: Eva María
authors.initials: EM
authors.lastname: Navarrete-Muñoz
authors.affiliation: Unidad de Química Clínica, Salud Pública Laboratorio de Bilbao, Bilbao, España.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Espada
authors.affiliation: CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, España; Departamento de Salud Pública, Universidad Miguel Hernández, Elche, Alicante, España.
authors.forename: Jesús
authors.initials: J
authors.lastname: Vioque
authors.affiliation: CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, España; IUOPA-Área de Medicina Preventiva y Salud Pública, Departamento de Medicina, Universidad de Oviedo, Oviedo, Asturias, España.
authors.forename: Adonina
authors.initials: A
authors.lastname: Tardón
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000453:epidemiology*
keywords: Dietary Supplements; Exposición solar; Ingesta; Intake; Sun exposure; Suplementos dietéticos; Vitamin D; Vitamina D