Diabetes is quickly becoming a global epidemic, and in 2011, a number of studies identified a connection between low vitamin D levels and an increased risk of gestational diabetes (GDM). One of these, published online in Diabetic Medicine in December, was led by Dr. Lorraine Lipscombe.
“Our study adds to the growing body of evidence suggesting that vitamin D supplementation can lower the rate of gestational diabetes,” says Lipscombe.
Poorly controlled pre-existing diabetes and GDM are not only unsafe for women, but also increase the risk of macrosomia (also known as “big baby syndrome”), as well as future diabetes. But scientists can’t yet be sure if low vitamin D levels are merely correlated with higher rates of GDM, or if low levels actually contribute to the disease.
However, studies have shown that supplemental vitamin D may prevent or delay the onset of diabetes and reduce complications for those who have already been diagnosed. But since these studies weren’t done in pregnant women, doctors remain cautious about recommending supplements to their pregnant patients.
“Doctors are rightly very careful to avoid harm,” Lipscombe says. “But we do know that women who are pregnant and breastfeeding need more vitamin D.”
Pregnant women in northern communities are already counselled to supplement with vitamin D, yet these recommendations haven’t yet translated to southern Canadian communities, where office jobs and winter weather often keep people out of the sun and vitamin D-depleted. Vitamin D levels tend to be even lower in people with darker skin – something to consider in multi-cultural areas.
“When it comes to the evidence around vitamin D, the recommendations are really lagging behind the science,” says Lipscombe.
Dr. Lorraine Lipscombe is supported by the Canadian Institutes of Health Research (CIHR), the Canadian Diabetes Association, the Ontario Institute for Cancer Research and the Lawson Foundation. In 2012, she was awarded a prestigious Canadian Institutes of Health Research New Investigator Award, and appointed medical director of the Centre for Integrated Diabetes Care, Institute of Health Systems Solutions and Virtual Care (Women’s College Hospital). She is a Women’s College scientist and endocrinologist, and an assistant professor in the Department of Medicine at the University of Toronto.