Serum vitamin D and subsequent occurrence of type 2 diabetes

Epidemiology. 2008 Sep;19(5):666-71. doi: 10.1097/EDE.0b013e318176b8ad.


Background: Low vitamin D status has been suggested as a risk factor for type 2 diabetes. Although the epidemiologic evidence is scarce, 2 recent studies have suggested an association. The present study investigated the relation of serum vitamin D with type 2 diabetes incidence using pooled data from these 2 cohorts.

Methods: Two nested case-control studies, collected by the Finnish Mobile Clinic in 1973-1980, were pooled for analysis. The study populations consisted of men and women aged 40-74 years and free of diabetes at baseline. During a follow-up period of 22 years, 412 incident type 2 diabetes cases occurred, and 986 controls were selected by individual matching. Serum vitamin D (serum 25(OH)D) was determined from frozen samples, stored at baseline. Pooled estimates of the relationship between serum vitamin D concentration and type 2 diabetes incidence were calculated.

Results: Men had higher serum vitamin D concentrations than women and showed a reduced risk of type 2 diabetes in their highest vitamin D quartile. The relative odds between the highest and lowest quartiles was 0.28 (95% confidence interval = 0.10-0.81) in men and 1.14 (0.60-2.17) in women after adjustment for smoking, body mass index, physical activity, and education.

Conclusions: The results support the hypothesis that high vitamin D status provides protection against type 2 diabetes. Residual confounding may contribute to this association.

MeSH terms

  • Adult
  • Aged
  • Case-Control Studies
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Female
  • Finland / epidemiology
  • Follow-Up Studies
  • Humans
  • Life Style
  • Logistic Models
  • Male
  • Middle Aged
  • Sex Distribution
  • Vitamin D / blood*


  • Vitamin D