Cholecalciferol improves glycemic control in type 2 diabetic patients: a 6-month prospective interventional study

Abstract

Background and purposeTo investigate the effects of vitamin D supplementation on glucose homeostasis and lipid profile in type 2 diabetic patients who have vitamin D deficiency.Patients and methodsOne hundred twenty-five type 2 diabetic patients taking oral hypoglycemic agents as mono- or combination therapy were recruited from the diabetes and endocrinology clinic. Subject demographics, duration of diabetes, antidiabetic medication, body mass index (BMI), pulse, and blood pressure (BP) were assessed. Laboratory measurements of serum vitamin D3 level, hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and lipid profile were measured. Homeostatic model assessment-insulin resistance (HOMA-IR) was calculated whenever fasting insulin (FI) was available. Forty-one patients (27 males and 14 females) were started on cholecalciferol replacement–45,000 units once weekly for 8 weeks and then 22,500 units once weekly for 16 weeks. Calcium carbonate tablets 500 mg once daily were also prescribed for the initial 2 months of treatment. Measured variables were reassessed after 6 months of replacement therapy. During the trial, subjects were instructed not to change their diabetes drugs or lifestyle.ResultsNo significant association was found between vitamin D3 level and any of the measured variables apart from a significant positive correlation with blood urea nitrogen. Vitamin D3 replacement was associated with a significant increase in its level (14.0±4.0 vs 31.0 vs 7.9 ng/mL, P<0.001). This was associated with a significant reduction of HbA1c (7.9±1.7 vs 7.4%±1.2%, P=0.001) and FPG (9.1±4.3 vs 7.9±2.4 mmol/L, P=0.034). Mean reduction of HbA1c was 0.54% and that of FPG was 1.22 mmol/L. FI, c-peptide and insulin resistance (IR) were reduced but this was statistically insignificant (P=0.069, 0.376, 0.058, respectively). FI decreased by 22%, HOMA-IR by 27.6%, and c-peptide by 1.83%. Total cholesterol, low-density lipoprotein cholesterol, parathyroid hormone, alkaline phosphatase, serum creatinine, and pulse rate significantly decreased (4.3±0.9 vs 4.0±0.9 mmol/L, P=0.036; 2.5±0.8 vs 2.2±0.8 mmol/L, P=0.018; 4.6±2.1 vs 3.5±1.8 pmol/L, P=0.001; 82.1±26.2 vs 66.2±19.5 U/L, P<0.001; 74.6±15.6 vs 70.7±14.7 μmol/L, P=0.047; and 81.6±11.9 vs 77.5±12.0 bpm, P=0.045, respectively). Triglycerides and high-density lipoprotein cholesterol, both systolic and diastolic BP, and BMI did not show significant change.ConclusionCholecalciferol helps improve blood glucose control and cholesterol profile in vitamin D3-deficient type 2 diabetic patients.

The Association of Serum Vitamin D Deficiency and Metabolic Risk Factors in Chinese Adults with Prediabetes: A Cross-Sectional Study

“…In addition, the elevated intact parathyroid hormone (iPTH) observed in subjects with low 25(OH)D3 levels might play a causal role in the pathogenesis of increased adiposity (33). Similarly to our results, many studies have reported that patients with insufficient levels of vitamin D have high prevalence of dyslipidemia, they showed that the use of this vitamin might reduce levels of TG, TC, and might improve HDL-C level (34)(35)(36)(37). Vitamin D is shown to exert a role in the transportation of cholesterol by regulating the apolipoprotein A-1 levels, and it may act in the reduction of LDL-C uptake, may decrease the formation of foam cells, and may enhance the production of HDL-C.…”

The correlation between vitamin D deficiency and the severity of painful diabetic neuropathy in patients with type 2 diabetes mellitus (T2DM)

“…of glycemic control refl ected by HbA1c is signifi cantly related to vitamin D level. The same thing also found in another study that there is a signifi cant relationship in the vitamin D supplementation to decrease HbA1c (7.9±1.7% vs 7.4±1.2%, p=0.001) (27).…”

Metabolic effects of oral vitamin D supplementation as an adjuvant therapy on subjects with type 2 diabetes

“…Another study from Egypt investigated the effects of vitamin D supplementation on glucose homeostasis and lipid profile in 125 T2DM subjects having vitamin D deficiency. 15 Vitamin D3 replacement was associated with a significant increase in its level (14.0±4.0 vs 31.0 vs 7.9 ng/mL, P<0.001). This was associated with a significant reduction of HbA1c (7.9±1.7 vs 7.4%±1.2%, P=0.001).…”