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Fig. 1 | BMC Medical Research Methodology

Fig. 1

From: Assessment of research waste part 2: wrong study populations- an exemplar of baseline vitamin D status of participants in trials of vitamin D supplementation

Fig. 1

Panel a shows the number of randomized controlled trials (RCTs) of vitamin D with clinical endpoints in the Abstract published over time by year (bars) and cumulatively (line). Panel b shows the distribution of mean/median baseline 25-hydroxyvitamin D (25OHD) concentrations in these RCTs. Panel c shows the 25OHD concentrations plotted against year of publication with a line of best fit. Panel d shows the proportion of trials with mean/median baseline 25OHD < 25, 25–49, 50–74 and ≥ 75 nmol/L by year of publication. Above each bar is the number of trials

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BMC Medical Research Methodology

ISSN: 1471-2288

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