One in six expectant mothers deficient in vitamin D

A study that found one in six mums-to-be are deficient in the sunshine vitamin could bolster the case for introducing pregnancy-specific guidelines for vitamin D.

That is according to researchers at University College Cork (UCC) whose survey of 1,786 pregnant women attending Cork University Maternity Hospital found 17% had a vitamin D deficiency.

The study, designed to explore whether there was a connection between vitamin D status in early pregnancy and any major pregnancy complications, found 17% of the pregnant women were at high risk of vitamin D deficiency, compared with 12% of non-pregnant women of the same age. It reported a lower risk of pregnancy complications among women with high vitamin D status.

Professor Mairead Kiely, co-director of the Cork Centre for Vitamin D and Nutrition Research at UCC, said they are already talking with food producers about finding ways to increase vitamin D intake through food.

“We are trying to see how best to develop strategies to increase vitamin D intake taking a food-first approach, rather than necessarily relying on supplements,” said Prof Kiely.

The results of the study, published today in the American Journal of Clinical Nutrition, follow an analysis of vitamin D status using blood samples taken at 15 weeks’ gestation. Because the participants are part of the wider SCOPE (screening for pregnancy endpoints) study, researchers could compare their vitamin D data with the women’s pregnancy outcomes.

Researchers reported that having a high amount of vitamin D is associated with lower risk of pregnancy complications such as pre-eclampsia and small-for-gestational age birth.

Prof Kiely, who leads the Maternal and Child Nutrition research programme at INFANT, a perinatal research centre, said the next step is to establish optimal vitamin D intake for pregnant women, work which is already under way and due for completion in October.

The data from that study would provide the evidence to make pregnancy-specific recommendations for vitamin D to prevent deficiency and protect mothers and their babies, she said.

Prof Kiely is co-ordinating the European Commission-funded ODIN project which is working to develop solutions to prevent vitamin D deficiency and improve vitamin D-related health outcomes using a food-first approach.

Prof Kiely said vitamin D intakes in Ireland are “roughly half” of what is recommended internationally. She said this is due to a number of reasons, including that naturally occurring sources “are few and far between” and that the Government had “never taken a strategic look at how to fortify food with vitamin D”, as had been done in Finland.