RESUMEN
Type 2 diabetic elderly women are at increased risk for osteoporotic fractures. Low levels of vitamin D increases this risk. We aimed to measure levels of 25 hydroxy vitamin D [25 OH-D] in these patients to help assess the level of risk. In this cross sectional case-control study, the serum concentrations of 25 OH-D were measured by high performance liquid chromatography [HPLC] in 60 ambulatory, postmenopausal, type 2 diabetic female patients under oral anti-diabetic treatment. Thirty control females were comparable for weight, age and years since menopause. Calcium and Vitamin D intake [obtained by 24 hour dietary recall], sun exposure, parathyroid hormone [PTH], serum calcium, phosphorus and alkaline phosphatase were also assessed. The prevalence of 25 OH-D insufficiency was significantly higher in diabetic patients than in control subjects [38.3% vs. 20%, p<0.01]. About 13% of diabetics with vitamin D insufficiency had high PTH levels. While most of the control group with 25 OH-D insufficiency had elevated PTH levels. Out of 66 diabetic women, only 11.7% had adequate vitamin D intake and 30% had adequate calcium intake. Similarly, in non-diabetic women, only 13.3% had adequate vitamin D intake and 26.7% had adequate calcium intake. However, a highly significantly percentage of diabetic women [43.4%] with inadequate vitamin D intake develop vitamin D insufficiency compared with non-diabetic women [23.1%] [p<0.001]. Diabetic patients with 25 OH-D insufficiency tend to be older, with higher BMI, and HBA[IC] [P<0.01, <0.01, <0.001 respectively]. We documented increased risk of vitamin D insufficiency in type 2 diabetic postmenopausal women in the face of inadequate dietary vitamin D and low sun exposure. This finding might partially explain the increased risk for osteoporosis among this group and warrants consideration of dietary vitamin D supplementation