Table 2

Smallest detectable OR (above the null) according to proportion of controls exposed to low vitamin D (25(OH)D) and high leptin levels, using a power of 0.80 and a significance level of 0.05

Proportion of exposed controlsStudy II
Cases=700, 
ratio=1:1		Study III
Cases=345, 
ratio=1:1		Study IV
Cases=60, 
ratio=1:3
5%*1.822.263.81
30%†1.371.572.34
20%‡1.431.65–

  • *Exposure = 25(OH)D <30 nmol /L.

  • †Exposure = 25(OH)D <50 nmol /L.

  • ‡Exposure = high serum leptin levels ≥4.1 ng/mL).

  • 25(OH)D, 25-hydroxyvitamin D.