Summary of papers employing predicted 25(OH)D score to examine associations between vitamin D status and health outcomes.

<p>^a Adjusted for waist circumference in <i>Stage II</i>;</p><p>^b Since backwards stepwise regression was employed, the instrumental variables used varied across regressions.</p><p>Summary of papers employing predicted 25(OH)D score to examine associations between vitamin D status and health outcomes.</p

<i>Stage-II</i> estimates of the coefficient for each of the variables (x, y, D) included in the Cox proportional hazard models for different specifications, Monte Carlo simulations, sample size 5000, <i>d</i>₁ = 0.2 and <i>δ</i>₁ = 0.4.

<p>^a<i>z</i>₁ is the only instrumental variable, but it is invalid;</p><p>^b<i>z</i>₁ and <i>z</i>₂ are the invalid and valid instrumental variables respectively;</p><p>^c<i>z</i>₂ is the only instrumental variable, and it is valid. Specification III is correct.</p><p><i>Stage-II</i> estimates of the coefficient for each of the variables (x, y, D) included in the Cox proportional hazard models for different specifications, Monte Carlo simulations, sample size 5000, <i>d</i>₁ = 0.2 and <i>δ</i>₁ = 0.4.</p

Estimates of the association between the 25(OH)D concentration and the health outcome (<i>ϴ</i>) according to the change in (a) <i>d</i>₁, with <i>δ</i>₁ = 0.4 and (b) <i>δ</i>₁, with <i>d</i>₁ = 0.2; sample size 5000, Specification I and II.

<p>Estimates of the association between the 25(OH)D concentration and the health outcome (<i>ϴ</i>) according to the change in (a) <i>d</i>₁, with <i>δ</i>₁ = 0.4 and (b) <i>δ</i>₁, with <i>d</i>₁ = 0.2; sample size 5000, Specification I and II.</p

Summary of characteristics according to vitamin D status (based on measured serum 25(OH)D concentration) among 4,002 adults of the National Health and Nutrition Examination Survey (2005–06), American adults who had three readings of systolic blood pressure.

<p>^a P values were derived from Kolmogorov-Smirnov tests;</p><p>^b P values for trend (two-sided) were derived from trend tests.</p><p>Summary of characteristics according to vitamin D status (based on measured serum 25(OH)D concentration) among 4,002 adults of the National Health and Nutrition Examination Survey (2005–06), American adults who had three readings of systolic blood pressure.</p

The effect of omitting <i>z</i> from the health outcome equation.

<p>In theory, the total effect of <i>z</i> on health outcome, H, is <i>δ</i> + <i>θd</i>. In practice, using <i>z</i> as an instrumental variable causes bias in the estimated effect of the 25(OH)D score, <i>D</i>, on the health outcome, because the direct effect of <i>z</i> on the health outcome is incorrectly captured as being mediated by <i>D</i>.</p

Additional file 1: of Investigating the patterns and determinants of seasonal variation in vitamin D status in Australian adults: the Seasonal D Cohort Study

Questionnaires and sun diary for the Seasonal D Study. (PDF 482 kb

Additional file 2: of Investigating the patterns and determinants of seasonal variation in vitamin D status in Australian adults: the Seasonal D Cohort Study

Reporting against the STROBE guidelines. (DOC 101 kb

Supplementary_Data_Content_2 – Supplemental material for Vitamin D metabolites are lower with active Crohn’s disease and spontaneously recover with development of remission

Supplemental material, Supplementary_Data_Content_2 for Vitamin D metabolites are lower with active Crohn’s disease and spontaneously recover with development of remission by Craig Haifer, Ian C. Lawrance, Jacqueline R. Center, Michael W. Clarke, Prue H. Hart, John A. Eisman, Robyn Lucas and Simon Ghaly in Therapeutic Advances in Gastroenterology</p

Supplementary_Data_Content_1 – Supplemental material for Vitamin D metabolites are lower with active Crohn’s disease and spontaneously recover with development of remission

Supplemental material, Supplementary_Data_Content_1 for Vitamin D metabolites are lower with active Crohn’s disease and spontaneously recover with development of remission by Craig Haifer, Ian C. Lawrance, Jacqueline R. Center, Michael W. Clarke, Prue H. Hart, John A. Eisman, Robyn Lucas and Simon Ghaly in Therapeutic Advances in Gastroenterology</p