Table 1.
Factors Contributing to Low Vitamin D Levels in Diabetes
| Dietary intake | Limited intake of foods high in vitamin D |
| Sun Exposure | Lack of outdoor physical activity due to possible fatigue, obesity, and or mobility issues |
| Obesitya | More vitamin D is stored in the fatty tissues and less is biologically active in the serum |
| Renal Insufficiency | Less biologically active vitamin D since conversion to the active form occurs in the kidneys |
| Genetic variations | Polymorphisms of vitamin D binding protein Polymorphisms of CYP2R1 gene (which is necessary to catalyze the formation of the main circulating vitamin D metabolite) |
a
Obesity is associated with inflammation, but low levels of vitamin D are also associated with inflammation. Cytokines and other inflammatory agents have been linked to beta cell damage which then impairs insulin synthesis and secretion.