GDM: Vitamin D, Calcium Combo Improves Metabolic Profile

Diedtra Henderson

June 25, 2014

Women with gestational diabetes mellitus (GDM) who took supplemental calcium plus vitamin D at 24 to 28 weeks' gestation experienced a number of benefits, including reduced fasting plasma glucose, serum insulin levels, and serum low-density lipoprotein (LDL) cholesterol levels and increased high-density lipoprotein (HDL) cholesterol levels, according to a randomized, placebo-controlled trial.

Zatollah Asemi, PhD, from the Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Iran, and coauthors present the results of their trial in an article published online June 23 in Diabetologia.

Although GDM affects just 7% of pregnancies in the United States, prevalence rates can soar to 14% elsewhere in the world, Dr. Asemi and colleagues write, depending on diagnostic criteria and population studied. The ailment increases women's risk for insulin resistance, preeclampsia, and preterm delivery.

In an earlier study, the researchers found that giving supplemental vitamin D resulted in improved insulin function and lowered concentration of LDL cholesterol, but vitamin D and calcium are thought to pack a more beneficial punch when taken in tandem, the authors write, adding that pregnancy itself intensifies the body's demands for both supplements.

From September 2013 to November 2013, the authors recruited 56 pregnant women aged 18 to 40 years with GDM at 24 to 28 weeks' gestation. Twenty-eight of the women were randomly assigned to a treatment group, receiving 1000 mg calcium carbonate daily and 50,000 U vitamin D3 twice during the 6-week intervention. The remaining 28 women were assigned to receive placebos for both supplements that were identical in color, shape, size, and packaging, according to the authors. The US Food and Drug Administration's laboratory in Tehran ensured quality control of the supplements. Although 5 women were excluded (3 in the treatment group and 2 in the placebo group), the intent-to-treat analysis was conducted on all 56 participants.

Women who took the supplements experienced a significant reduction in fasting plasma glucose (−0.89±0.69 vs +0.26±0.92 mmol/L; P < .001), serum insulin levels (−13.55±35.25 vs +9.17±38.50 pmol/L; P = .02), and homeostatic model assessment-insulin reduction (−0.91&pusmn;1.18 vs + 0.63±2.01; P = .001) and a significant increase in quantitative insulin-sensitivity check index (+0.02±0.03 vs −0.002±0.02; P = .003) compared with those who took placebo.

In addition, women who took the supplements saw a significant reduction in serum LDL cholesterol levels (−0.23±0.79 vs +0.26±0.74 mmol/L; P = .02) and total cholesterol:HDL cholesterol ratio (−0.49±1.09 vs +0.18±0.37; P = .003) and a significant elevation in HDL cholesterol levels (+0.15±0.25 vs −0.02±0.24 mmol/L; P = .01) compared with women who took placebo.

The supplements also significantly increased total glutathione (+51.14±131.64 vs −47.27±203.63 μmol/L; P = .03) and prevented a rise in malondialdehyde levels (+0.06±0.66 vs +0.93±2.00 μmol/L; P = .03) compared with placebo.

"Calcium plus vitamin D supplementation in GDM women had beneficial effects on metabolic profile...this is important because elevated circulating levels of inflammatory markers and impaired insulin metabolism in GDM can predict the progression to type 2 diabetes...later in life and neonatal complications. Impaired insulin metabolism in women with GDM can result in adverse long term maternal outcomes and increased perinatal morbidity (babies large for gestational age, birth trauma, pre-eclampsia), and long-term consequences in the offspring. In addition, increased inflammatory markers in GDM might predict the future development of both metabolic and cardiovascular disease," the authors said in a news release.

In addition to such limitations as loss to follow-up, the authors did not assess the effects of supplemental vitamin D and calcium and ultimate pregnancy outcomes.

Financial support for the study was provided by Kashan University of Medical Sciences. The authors have disclosed no relevant financial relationships.

Diabetologia. Published online June 23, 2014. Full text


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.