Characteristics of individual studies for associations between VDR polymorphisms and IDD risks.

a<p>the mean age and/or the range of age;</p>b<p>11,12,22 represent tt, Tt, TT for <i>TaqI</i>(rs731236), ff, Ff, FF for <i>FokI</i> (rs2228570), and aa, Aa, AA for <i>ApaI</i> (rs7975232), respectively.</p>c<p><i>p</i> for Hardy–Weinberg equilibrium test in controls;</p><p>“NA” means that the data were not available.