Results of the quality assessment of observational studies.

<p>Results of the quality assessment of observational studies.</p

Forest plots of studies investigating vitamins.

<p>(A) Vitamin C; (B) Vitamin D; (C) Vitamin D deficiency (<20ng/ml); (D) Vitamin E.</p

Forest plots of studies investigating minerals.

<p>(A) Calcium; (B) Magnesium.</p

Vitamin and mineral status in the included studies.

<p>Vitamin and mineral status in the included studies.</p

Flow diagram.

<p>Flow diagram.</p

Results of the quality assessment of randomized controlled trials.

<p>Results of the quality assessment of randomized controlled trials.</p

Funnel plots.

<p>(A) Vitamin C; (B) Vitamin D; (C) Vitamin D deficiency (<20ng/ml); (D) Vitamin E; (E) Calcium; (F) Magnesium.</p