Irish pregnant women have vitamin D intakes far below those recommended for the normal development of a childs bones, according to research published in the European Journal of Clinical Nutrition.
The figures show that the average dietary intake of vitamin D among pregnant women in Ireland ranges from 1.9 2.1µg/d or some 80% below current recommended levels of 10µg/d (microgrammes daily) for the average adult.
Vitamin D insufficiencies during pregnancy can cause reduced bone growth in babies before birth and lead to poor bone development in early childhood. A severe vitamin D deficiency during pregnancy can cause childhood rickets.
Our skin naturally produces vitamin D through exposure to the sun (UVB sunlight). But in northern European countries, where there is a lack of sunlight exposure for much of the year, dietary sources of vitamin D can be particularly important.
Vitamin D is only found in a limited number of foods such as oily fish, egg yolk and liver. However, during pregnancy women are advised not to consume liver or undercooked eggs and to limit their intake of certain fish such as tuna.
Our findings reveal that pregnant women in Ireland have a poor dietary intake of vitamin D, says Fionnuala McAuliffe, Professor of Obstetrics and Gynaecology at the UCD School of Medicine and Medical Science, University College Dublin, and the National Maternity Hospital, Dublin, who led the study.
Their diet which includes meat, eggs and fortified breakfast cereals simply does not provide the recommended levels of the vitamin.
The study, funded by the Health Research Board, shows that less than one-quarter of the pregnant women surveyed consumed oily fish (salmon or mackerel), the best dietary source of vitamin D.
It also shows that women are often guided towards plain carbohydrate foods (low in vitamin D) during early pregnancy to alleviate the experiences of nausea.
A planned mixed diet including one to two portions of oily fish such as salmon or mackerel per week, more eggs, and fortified breakfast cereals can help women increase their vitamin D intake during pregnancy, says Ciara McGowan, a Research Dietitian at University College Dublin and the National Maternity Hospital who co-authored the study.
According to the Irish scientists, vitamin D supplements should be considered for pregnant women across the EU whose diets are deficient in vitamin D rich foods.
In another study published in the Journal of Bone and Mineral Research on 26 June 2011 scientists from the Medical University of South Carolina in Charleston have shown that vitamin D supplementation (even at high levels) during pregnancy has no adverse effects in women and their newborns.
The Irish study involved sixty-four women, over 18 years of age, from early pregnancy to childbirth. It excluded women taking vitamin D supplements. In 2009, there were over 76,000 births were registered in Ireland in 2009, the highest rate across all EU member states, according to figures from the Economic and Social Research Institute.