Abstract

To the Editor:

Although several studies have looked at vitamin D status in patients with diabetes, there is a paucity of data from practices specializing predominantly in diabetes. We assessed 25-hydroxyvitamin (OH) D levels in 133 patients (116 with type 2 and 17 with type 1 diabetes) seen in an outpatient diabetes unit of an academic medical center. Patients who had advanced congestive heart failure (New York Heart Association stage III and IV), active malignancy, stage 5 kidney disease, known vitamin D deficiency, or derangements of calcium-parathyroid metabolism were excluded. The group included 52 men and 81 women (89 Caucasian, 39 African American, and 5 Asian) with an average age of 54 years. Mean serum calcium was 9.45 mg/dL (reference range 8.6 to 10.2), average glycosylated hemoglobin (HbA1c) was 6.9%, mean serum creatinine was 1.06 mg/dL (reference range 0.5 to 1.3), and the majority (38/133, or 71.4%) had estimated glomerular filtration rate (eGFR) values greater than 60 mL/min. Following a recently proposed classification,¹ 68 patients (51.1%) were “deficient” (≤20 ng/mL), 32 patients (24%) were “relatively insufficient” (21–29 ng/mL), and only 33 patients (24.8%) qualified as having “sufficient” 25 (OH) vitamin D levels (≥30 ng/mL).