Table 3

Subgroup analysis of the effect of vitamin D on new-onset diabetes

No. of trialsNo. of patientsI2RR (95% CI)Pinteraction
Overall84,8960%0.89 (0.80, 0.99)
Baseline 25(OH)D (nmol/L)
  ≥5032,5170%0.90 (0.80, 1.02)0.79
 <5051,12226%0.87 (0.68, 1.11)
Baseline 25(OH)D (nmol/L)
  ≥3073,6400%0.89 (0.80, 1.00)NA
 <3000NANA
Achieved 25(OH)D in vitamin D group (nmol/L)
  ≥7574,7340%0.90 (0.81, 1.00)NA
 <7500NANA
Type of vitamin D
 Vitamin D374,7230%0.89 (0.80, 0.99)0.81
 Vitamin D21173NA0.99 (0.41, 2.37)
Daily dose equivalent (IU)
  ≥2,00084,8960%0.89 (0.80, 0.99)NA
 <2,00000NANA
Mean BMI (kg/m2)
  ≥3052,5140%0.95 (0.84, 1.08)0.048
 <3031,1264%0.73 (0.57, 0.92)
Timing of treatment
 Daily23,6790%0.90 (0.80, 1.03)0.70
 Intermittently61,2178%0.86 (0.66, 1.10)
 Intervention
Vitamin D vs. placebo74,7710%0.90 (0.81, 1.01)0.07
Vitamin D + calcium vs. calcium1125NA0.39 (0.16, 0.95)
Latitude
  ≥37°33,5570%0.89 (0.79, 1.00)0.85
 <37°61,33915%0.86 (0.63, 1.18)
Follow-up
  ≥3 years34,1900%0.91 (0.81, 1.01)0.28
 <3 years57060%0.70 (0.45, 1.10)
  • To convert Vitamin D IU to μg, multiply by 0.0025. NA, not available.