วิธีการMedline and Web of Science databases were searched for articles through the Web of Knowledge portal between January 2013 and June 2014. Terms used to identify potential articles included vitamin D, vitamin D supplementation, vitamin D therapy,vitamin D treatment, calcitriol, calcidiol, ergocalciferol, cholecalciferol, paricalcitol,alphacalcidol, maxacalcitol, or doxercalciferol; and one of: quality of life, health-related quality of life, Medical Outcomes Study Short Form 36-Item questionnaire (SF-36), Research and Development Corporation Short Form 36-item questionnaire (RAND-36), EuroQOL five dimension questionnaire (EQ-5D), Health Utilities Index questionnaire (HUI), Medical Outcomes Study Short Form 12-item questionnaire (SF-12), Research And Development Corporation Short Form 12-item questionnaire (RAND-12), Medical Outcomes Study Short Form 6-dimension questionnaire (SF-6D), or World Health Organization Quality of Life questionnaire (WHOQOL). Titles and abstracts of retrieved studies were reviewed for inclusion. Criteria were: English-language articles available online (published between 1950 and May 2014), primary research articles, studies conducted on human subjects, and treatment/supplementation with vitamin D. Articles were excluded if they involved topical vitamin D application or implicit cotreatment with other vitamins (eg, multivitamins). The majority of studies we reviewed were randomized controlled trials or involved some aspect of randomization and treatment (73%). Qualitative results of the systematic review are presented herein. However, a meta-analysis was not conducted due to the limited number of studies available that met inclusion criteria. To ensure rigor in this review, an examination of methodologic quality was conducted for each article as proposed by Jadad and colleagues. 15 Jadad scoring is widely used (cited in >3,000 articles) for the assessment of randomized controlled trials.16 and 17 Additional criteria specific to vitamin D namely the assessment of 25(OH)D levels in study participants and evidence of quantification of dietary vitamin D intake/endogenous synthesis via sunlight exposure was also added to this review. The maximum score possible for any individual study was 8 points. Effect sizes were determined by assessment of Cohen’s d and r values using a Cohen’s d<0.2 as no effect, 0.2 to 0.5 as small effect, 0.5 to 0.8 as medium effect, and >0.8 as a large effect. 18ผลลัพธ์A total of 15 articles were included in this review.19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,32 and 33Figure 1 depicts the selection process and article exclusion criteria in a preferred reporting items for systematic reviews and meta-analyses flow diagram.34 The majority (98%) of publications retrieved through the literature search were excluded during the phase of title/abstract assessment. Table 1 summarizes the basic methodology and study characteristics of each clinical trial. Eight of the reviewed articles reported data on short-term studies (<6 months’ duration).19, 21, 24, 25, 29, 31, 32 and 33 Only three studies were conducted in healthy/nondiseased populations.20, 21 and 30 Sample sizes ranged from 28 to 33,067 participants. The majority of studies had a control group as part of their methodology. Table 2 describes the vitamin D-specific study characteristics, process, and methodology. Five of the articles described interventions which were high dose25, 26,29, 31 and 32 and, of note, almost all of the long-term trials investigated low doses of vitamin D. The study populations from the selected articles all had suboptimal average baseline 25(OH)D levels (<75 nmol/L [30 ng/mL]) and 70% were also insufficient (<50 nmol/L [20 ng/mL]). Most interventions examined the effects of oral cholecalciferol supplementation. Total doses of the nutritional forms of vitamin D (ie, cholecalciferol and ergocalciferol) ranged from 109,800 IU to 1,512,800 IU during the course of study duration. Two articles examined the therapeutic effects of supplementation with active vitamin D compounds.23 and 28.
การแปล กรุณารอสักครู่..
