8 April 2011
Australian experts are calling for routine vitamin D testing in all pregnant women, after finding a novel association between low blood vitamin D levels and gestational diabetes (diabetes that develops during pregnancy).
Researchers Dr Sue Lynn Lau and Dr Jenny Gunton found an independent inverse association between serum vitamin D levels and HbA1c (a measure of long-term blood sugar control), suggesting that low vitamin D "may contribute to impaired glucose [sugar] tolerance during pregnancy".
(HbA1c, or glycosylated haemoglobin, measures how tight blood sugar control has been over the previous few months. The research found that low vitamin D levels were linked with high HbA1c values, indicating less-tight blood sugar control.)
Vitamin D insufficiency or deficiency was found in 41 per cent of the 147 pregnant women in the Sydney study (Med J Aust 2011; 194: 334-7).
Thirty-three per cent of the women in the study were of subcontinental Indian ethnicity, 29 per cent East or South-East Asian, 19 per cent Caucasian, 12 per cent Middle Eastern and 7 per cent of other ethnicity.
There was no association in the study between lower vitamin D and body mass index (BMI), suggesting that body weight is unlikely to account for the relationship between vitamin D and diabetes, the researchers said.
Dr Alison Nankervis, president of the Australasian Diabetes in Pregnancy Society, called for universal vitamin D testing in early pregnancy as well as subsidies for women to reduce the cost of supplements.
Last Reviewed: 08 April 2011