Asghari Golaleh, Farhadnejad Hossein, Hosseinpanah Farhad, Moslehi Nazanin, Mirmiran Parvin, Azizi Fereidoun
Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
BMJ Open. 2018 Sep 19;8(9):e021636. doi: 10.1136/bmjopen-2018-021636.
The importance of vitamin D for bone health as well as its role in non-skeletal functions has long been documented. However, review investigations on the effect of vitamin D supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in children and adolescents are scarce. The aims of the current study were to assess the impact of various doses of vitamin D supplementation on serum 25(OH)D concentrations in children and adolescents, and to identify relevant determinants of variations in the effect of vitamin D supplementation.
PubMed, Scopus, ISI Web of Science and Cochrane Central Register of Controlled Trials databases up to 27 September 2017 will systematically be searched for randomised controlled trials of vitamin D supplementation. We considered articles with the following control groups as eligible: placebo control, control group without any supplementation or a comparative arm investigation. Two reviewers will assess articles for eligibility according to prespecified selection criteria, after which data extraction and quality appraisal will be conducted by two independent reviewers. The quality assessment will be assessed using the Jadad scale. Meta-analyses will be conducted where appropriate. We will express continuous measures (ie, serum 25(OH)D concentration) as mean differences with 95% CIs. Heterogeneity of the data will be investigated via visual inspection of the forest plots and using χ test on N-1 df, with a significance level of α=0.1. We will also assess individual study and subgroup characteristics and perform a sensitivity analysis. Publication bias will be assessed using funnel plot and statistical analysis of Egger's test.
Ethics approval is not required because the work will be carried out on published documents. The authors will publish findings from this review through peer-reviewed publication or conference presentations.
CRD42017067179.
维生素D对骨骼健康的重要性及其在非骨骼功能中的作用早已得到证实。然而，关于补充维生素D对儿童和青少年血清25-羟基维生素D（25(OH)D）水平影响的综述性研究却很少。本研究的目的是评估不同剂量的维生素D补充剂对儿童和青少年血清25(OH)D浓度的影响，并确定维生素D补充效果差异的相关决定因素。
截至2017年9月27日，将系统检索PubMed、Scopus、ISI科学网和Cochrane对照试验中央注册库数据库中关于维生素D补充剂的随机对照试验。我们将以下对照组的文章视为合格：安慰剂对照、无任何补充剂的对照组或比较组研究。两名评审员将根据预先设定的选择标准评估文章的合格性，之后由两名独立评审员进行数据提取和质量评估。质量评估将使用Jadad量表进行。将在适当情况下进行荟萃分析。我们将连续测量值（即血清25(OH)D浓度）表示为具有95%置信区间的平均差异。将通过森林图的视觉检查和使用自由度为N-1的χ检验来研究数据的异质性，显著性水平α=0.1。我们还将评估个体研究和亚组特征并进行敏感性分析。将使用漏斗图和Egger检验的统计分析来评估发表偏倚。
由于这项工作将基于已发表的文献进行，因此无需伦理批准。作者将通过同行评审出版物或会议报告发表本综述的研究结果。
PROSPERO注册号：CRD42017067179。
