D-vitaminsupplementering och dess effekt på kroppssammansättning hos överviktiga och obesa ? en systematisk översiktsartikel
Sahlgrenska Academyat University of GothenburgDepartment of Internal Medicine and Clinical NutritionAbstractTitle: Vitamin D supplementation and its effect on body composition in the overweightand obese ? a systematic reviewAuthor: Johanna Blum and Emma Sellin FrimodigSupervisor: Sofia KlingbergExaminer: Ingrid LarssonProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: April 10, 2013Background: There is an increasing burden of overweight and obesity worldwide. Theconditions lead to morbidity and lowered quality of life. Since there is research showing aconnection between obesity and low levels of serum 25(OH)D, this raises the question ifsupplementation of vitamin D may have positive effects on body weight, waist circumference andbody composition in the overweight and obese.Objective: To investigate if there is enough scientific evidence to recommend vitamin Dsupplementation combined with nutrition therapy to overweight and obese patients.Search strategy: The systematic collection of data was performed in the databases PubMed andScopus. Search terms included were ?vitamin D supplementation?, ?obesity? ?cohort?, ?vitamin D?,?vitamin D3 supplementation? and ?overweight?.Selection criteria: Human studies with RCT, CCT or cohort design written in English orSwedish were included. The participants had to be over 18 years old, have a BMI>25 kg/m2 andbe generally healthy. Studies lasting less than 12 weeks were excluded.Data collection and analysis: After the data collection the quality of the selected studies wasanalysed using Granskningsmall för randomiserade studier and Granskningsmall för observationsstudier ochickerandomiserade kontrollerade studier, both published by the SBU. The outcome measures of thestudies were thereafter evaluated according to GRADE using Sammanfattande evidensformulär fromthe university of Gothenburg.Main results: Six studies of RCT design were included in this systematic review. Summarizedthey showed strong scientific evidence that vitamin D supplementation raises the levels of25(OH)D, moderate scientific evidence that vitamin D supplementation reduces visceral fat massand limited scientific evidence that supplementation reduces body fat mass. There was alsostrong scientific evidence that vitamin D supplementation does not have a reducing effect onbody weight, BMI or waist circumference.Conclusions: There are indications that a recommendation of vitamin D supplementation tooverweight and obese patients reduces visceral fat mass and possibly total fat mass. Vitamin Dsupplementationdoes not have a reducing effect on body weight, BMI or waist circumference.