Association of vitamin D(2) and D(3) with type 2 diabetes complications

AIMS: Vitamin D measurement is a composite of vitamin D(2) (25(OH)D(2)) and D(3) (25(OH)D(3)) levels, and its deficiency is associated with the development of type 2 diabetes (T2DM) and diabetic complications; vitamin D deficiency may be treated with vitamin D(2) supplements. This study was undertaken to determine if vitamin D(2) and D(3) levels differed between those with and without T2DM in this Middle Eastern population, and the relationship between diabetic microvascular complications and vitamin D(2) and vitamin D(3) levels in subjects with T2DM(.) METHODS: Four hundred ninety-six Qatari subjects, 274 with and 222 without T2DM participated in the study. Plasma levels of total vitamin D(2) and D(3) were measured by LC-MS/MS analysis. RESULTS: All subjects were taking vitamin D(2) and none were taking D(3) supplements. Vitamin D(2) levels were higher in diabetics, particularly in females, and higher levels were associated with hypertension and dyslipidemia in the diabetic subjects (p < 0.001), but were not related to diabetic retinopathy or nephropathy. Vitamin D(3) levels measured in the same subjects were lower in diabetics, particularly in females (p < 0.001), were unrelated to dyslipidemia or hypertension, but were associated with retinopathy (p < 0.014). Neither vitamin D(2) nor vitamin D(3) were associated with neuropathy. For those subjects with hypertension, dyslipidemia, retinopathy or neuropathy, comparison of highest with lowest tertiles for vitamin D(2) and vitamin D(3) showed no difference. CONCLUSIONS: In this Qatari cohort, vitamin D(2) was associated with hypertension and dyslipidemia, whilst vitamin D(3) levels were associated with diabetic retinopathy. Vitamin D(2) levels were higher, whilst vitamin D(3) were lower in diabetics and females, likely due to ingestion of vitamin D(2) supplements.