Does Vitamin D Play a Role in Glycemic Status? AACE

Vitamin D does not seem to be associated with glycemic control in subjects with diabetes mellitus, according to findings presented at the American Association of Clinical Endocrinologists 16th Annual Meeting and Clinical Congress (AACE) In a poster session on April 12th Jayalakshmi Udayasankar, MBBS, endocrine fellow, division of medicine, University of Washington, Seattle, Washington, United States noted that there are conflicting results among the few studies that have looked into the effect of vitamin D replacement on glycemic control in type 2 diabetes.

The researchers examined serum 25-(OH)D and plasma hemoglobin A1c (HbA1c) levels in 24 patients with type 1 diabetes and 29 with type 2 diabetes between May and October of 2006. Those whose 25-(OH)D were lower than 30 ng/mL were given 1200 IU of vitamin D each day.

Eighty-six percent (46/53) had insufficient levels of 25-(OH)D during the initial visit. The researchers found a negative correlation between age and 25-(OH)D levels (P = .04). No correlation was observed between 25-(OH)D and HbA1c (P = .55), and a sub-analysis separating the type 1 and type 2 subjects also did not show correlation (P = .83 and P = .28, respectively).

There were no correlations between 25-(OH)D and HbA1c levels in the low, middle or high tertiles of the initial 25-(OH)D level (P = .46, P = .06 and P = .22 respectively).

Nineteen percent (9/46) of participants who received vitamin D replacement therapy had follow-up measures of both 25-(OH)D and HbA1c during the study. All of these patients had 25-(OH)D levels greater than 30 ng/mL.

No significant correlation was found between the change in 25-(OH)D and HbA1c after vitamin D replacement.

A key finding is that the team did not see any significant correlation between vitamin D status and glycemic control even after separating the data for type 1 diabetes and type 2 diabetes. Notably, increasing vitamin D levels did not show a trend toward improved glycemic control.

The researchers noted that their findings may be limited by the small number of participants with follow up data, as do not account for the influence of subject characteristics known to impact glycemic control.

Though vitamin D did not seem to be associated with glycemic control in subjects in this study, Udayasankar noted there is room for more research. "Ours was a small study. What’s needed are more prospective controlled trials on vitamin D in diabetes," she said. "Vitamin D is a public health measure that could have a lot of impact."

[Presentation title: Does Vitamin D Status Correlate With Glycaemic Status in Diabetic Subjects? Abstract 326]

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DID YOU KNOW:

Camel’s milk can improve beta-cell function: Camel’s milk has been shown to possess insulin-like activities, which decrease the requirement for exogenous insulin in patients with type 1 diabetes. Now, the effect of camel’s milk, in reducing further destruction of beta-cells in patients with type 1 diabetes, has been studied in 50 newly diagnosed patients. Indications were that camel’s milk was associated with some improvement of beta-cell function though the effect was not statistically significant. A large-scale study is needed to establish whether camel’s milk has a role in type 1 diabetes. Diabetes Research and Clinical Practice, available on-line 12 March 2007: Agrawal R, Saran S, Sharma P, Gupta R, Kochar D, Sahani M Effect of camel milk on residual beta-cell function in recent onset type 1 diabetes