Table_6_Efficacy of intermittent versus daily vitamin D supplementation on improving circulating 25(OH)D concentration: a Bayesian network meta-analysis of randomized controlled trials.DOCX

BackgroundVitamin D deficiency is a widespread issue globally, resulting in increased use of vitamin D supplements. However, it is unclear whether intermittent (weekly or monthly) vitamin D supplementation is as effective as daily supplementation in improving circulating 25-hydroxyvitamin D [25(OH)D] levels.MethodsThree databases including Medline, EMBASE, and the Cochrane Library were systematically searched up to 10 November 2020. The risk of bias was evaluated according to Cochrane Collaboration’s tool for rating methodological quality assessment. Direct and indirect comparisons between interventions and controls were performed by a Bayesian network meta-analysis (NMA), where the mean difference (MD) and its 95% confidence interval (CI) were used to indicate the efficacy.ResultsThis NMA analysis included 116 RCTs with a total of 11,376 participants. Generally, we observed that 25(OH)D concentrations were significantly elevated regardless of vitamin D supplementation frequency. Although the findings of SUCRA indicated that daily vitamin D supplementation had a higher rank value than intermittent supplementation when the supplement dosage was similar, no statistically significant pooled mean differences of 25(OH)D concentration were noted between the daily supplementation group and intermittent supplementation group. Additionally, weekly supplementation with a total of 600,000 IU vitamin D supplementation during 3 months had the best efficacy in elevating 25(OH)D concentration (pooled MD = 63 nmol/L, 95%CI: 49–77). To achieve optimal 25(OH)D concentration (>75 nmol/L), we recommend 60,000 IU vitamin D supplementation monthly (~2,000 IU/day).ConclusionThe efficacy of intermittent vitamin D supplementation was similar to daily supplementation. Coupled with its convenience, the frequency and dosage of intermittent vitamin D supplements were recommended to reach the optimal 25(OH)D level.Systematic review registration:https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=257257, PROSPERO CRD42021257257.

全球范围内，维生素D缺乏症已成为一种普遍问题，导致维生素D补充剂的广泛应用。然而，间歇性（每周或每月）补充维生素D与每日补充维生素D在提高循环25-羟基维生素D [25(OH)D]水平方面的有效性尚不明确。研究方法：截至2020年11月10日，我们对包括Medline、EMBASE和Cochrane图书馆在内的三个数据库进行了系统检索。偏倚风险根据Cochrane协作组织的方法学质量评估工具进行了评估。通过贝叶斯网络荟萃分析（NMA）对干预措施与对照之间的直接和间接比较进行了分析，其中平均差异（MD）及其95%置信区间（CI）被用来表示疗效。研究结果：本NMA分析包括了116项随机对照试验（RCT），总计11,376名参与者。总体而言，我们观察到，无论维生素D补充频率如何，25(OH)D浓度均有显著升高。尽管SUCRA的结果表明，在补充剂量相似的情况下，每日维生素D补充剂的排名值高于间歇性补充，但在每日补充组和间歇性补充组之间，25(OH)D浓度没有观察到具有统计学意义的汇总平均差异。此外，在3个月内每周补充总计600,000 IU维生素D，对于提高25(OH)D浓度具有最佳疗效（汇总MD=63 nmol/L，95%CI：49–77）。为实现25(OH)D浓度（>75 nmol/L）的最优化，我们建议每月补充60,000 IU维生素D（约每日2,000 IU）。结论：间歇性维生素D补充剂的有效性与每日补充剂相似。考虑到其便利性，建议间歇性维生素D补充剂的频率和剂量以达到最佳的25(OH)D水平。系统综述登记：https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=257257, PROSPERO CRD42021257257。