title: Vitamin D status and its determinants in children and adults among families in late summer in Denmark.
abstract: The impact of the familial relationship on vitamin D status has not been investigated previously. The objective of the present cross-sectional study was to assess serum 25-hydroxyvitamin D (25(OH)D) concentration and its determinants in children and adults among families in late summer in Denmark (56°N). Data obtained from 755 apparently healthy children (4-17 years) and adults (18-60 years) recruited as families (n 200) in the VitmaD study were analysed. Blood samples were collected in September-October, and serum 25(OH)D concentration was measured by liquid chromatography-tandem MS. Information on potential determinants was obtained using questionnaires. The geometric mean serum 25(OH)D concentration was 72·1 (interquartile range 61·5-86·7) nmol/l (range 9-162 nmol/l), with 9 % of the subjects having 25(OH)D concentrations < 50 nmol/l. The intra-family correlation was 0·27 in all subjects, 0·24 in the adults and 0·42 in the children. Serum 25(OH)D concentration was negatively associated with BMI (P< 0·001) and positively associated with dietary vitamin D intake (P= 0·008), multivitamin use (P= 0·019), solarium use (P= 0·006), outdoor stay (P= 0·001), sun preference (P= 0·002) and sun vacation (P< 0·001), but was not associated with lifestyle-related factors in the adults when these were assessed together with the other determinants. In conclusion, the majority of children and adults among the families had serum 25(OH)D concentrations >50 nmol/l in late summer in Denmark. Both dietary and sun-related factors were determinants of vitamin D status and the familial component was stronger for the children than for the adults.
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Katja H
authors.initials: KH
authors.lastname: Madsen
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Lone B
authors.initials: LB
authors.lastname: Rasmussen
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Heddie
authors.initials: H
authors.lastname: Mejborn
authors.affiliation: Department of Applied Mathematics and Computer Science, Technical University of Denmark,DK-2800Lyngby,Denmark.
authors.forename: Elisabeth W
authors.initials: EW
authors.lastname: Andersen
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen,DK-1958Frederiksberg C,Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Mølgaard
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Janna
authors.initials: J
authors.lastname: Nissen
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Inge
authors.initials: I
authors.lastname: Tetens
authors.affiliation: Division of Nutrition, National Food Institute, Technical University of Denmark,Mørkhøj Bygade 19,DK-2860Søborg,Denmark.
authors.forename: Rikke
authors.initials: R
authors.lastname: Andersen
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003718:Denmark; D004032:Diet; D019587:Dietary Supplements; D005190:Family; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D012621:Seasons; D013472:Sunlight; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D