Vitamin D status in patients with type-2 diabetes mellitus in Riyadh City, Saudi Arabia

Background
Type-2 diabetes mellitus (T2DM) is a progressive and chronic disease characterized by both β-cell dysfunction and increased insulin resistance. Vitamin D is a crucial factor in the development of T2DM because it is necessary for normal insulin secretion. Despite ample sunshine, vitamin D deficiency is common in the Middle East.
Objective
To report the vitamin D status and its impact on the people in Riyadh City, Saudi Arabia, with T2DM.
Patients and methods
The study was carried out on 100 patients of 31–79 years old with T2DM. According to their vitamin D status, they were classified into three groups: group 1 (deficient, vitamin D: <20 ng/ml), group 2 (insufficient, vitamin D: 20–30 ng/ml), and group 3 (normal, vitamin D: >30 ng/ml). All were subjected to history taking, clinical examination, and assessment of fasting blood samples of serum concentrations of 25-hydroxy vitamin D [s-25(OH)D], blood glucose, glycated hemoglobin, lipid profile, liver enzymes (alanine transaminase and aspartate transaminase), urea and creatinine.
Results
Inadequate vitamin D level was observed in 80% of the participants, with a mean s-25(OH)D of 18.3±10.9 ng/ml. S-25(OH)D correlated negatively with fasting blood sugar (FBS) (=0.008), with cholesterol and low-density lipoprotein (=0.012 and 0.003, respectively). The low vitamin D status was strongly associated with poor glycemic control (=0.001) and in females (=0.002). There was no significant association between s-25(OH)D level and different age groups.
Conclusion
There is an overwhelming prevalence of vitamin D deficiency in our sample of Saudi diabetic patients. Association of low vitamin D status with poor glycemic control and atherogenic lipid profile suggests a role of vitamin D in the control of T2DM and dyslipidemia and the importance of early detection of its deficiency and vitamin D supplementation.