Pregnant women who have insufficient levels of vitamin D in their body may be more likely to suffer complications such as gestational diabetes and pre-eclampsia, a new study indicates.

Earlier this year, German scientists found that women with too much vitamin D in their bodies were more likely to have children who went on to develop allergies.

However, this latest study from Canada suggests that having too little of the vitamin can also cause problems.

Vitamin D is essential for healthy bones, but is present in very few foods. It is also known as the sunshine vitamin, because it is made in the body when ultraviolet rays from sunlight strike the skin. However, Ireland's northerly latitude and lack of winter sunlight means that we cannot make enough vitamin D in this way. As a result, some people choose to take supplements.

According to scientists from the University of Calgary, vitamin D insufficiency has been linked with a number of health issues, including adverse pregnancy outcomes. As research in this area is growing, they decided to investigate further by carrying out a major review of all the existing evidence linking vitamin D to pregnancy and birth outcomes.

They analysed 31 studies published between 1980 and 2012. Each study had between 95 and 1,100 participants.

The scientists found that women with low levels of vitamin D were more likely to develop gestational diabetes and pre-eclampsia (dangerously high blood pressure). They were also more likely to give birth to a small baby.

The scientists described these results as ‘concerning', due to the fact that vitamin D insufficiency is thought to be common in pregnancy, especially among particular women, such as those with limited sun exposure and vegetarians.

However, they said that more research in this area is needed to see whether ‘strategies to optimise vitamin D concentration are effective in improving pregnancy and neonatal outcomes'.

Details of these findings are published in the British Medical Journal.

For more information on pregnancy, see our Pregnancy Clinic here