Study: 90% of pregnant women lack key vitamins necessary for healthy pregnancies and infant wellbeing

Pregnant women are not getting the essential nutrients they and their babies need from modern diets say scientists, who have warned that the situation will likely worsen as more people turn to plant-based foods.

A study looking at the health of expecting mothers from high-income countries, including the UK, New Zealand and Singapore, found that 90 per cent were lacking key vitamins necessary for healthy pregnancies and the wellbeing of unborn infants.

Scientists from the University of Southampton, working with experts worldwide, surveyed more than 1,700 women and found most were missing essential nutrients found in abundance in meat and dairy products.

These included vitamins B12, B6 and D, folic acid and riboflavin which are essential for the development of fetuses in the womb.

Lead author and Professor of Epidemiology Keith Godfrey, from the University of Southampton, said the prevalence of vitamin deficiencies among women attempting to become pregnant in wealthy countries is a serious concern.

The push to reduce our dependence on meat and dairy to achieve net-zero carbon emissions is likely to further deplete expecting mothers of vital nutrients, which could have lasting effects on unborn children.

Our study shows that almost every woman trying to conceive had insufficient levels of one or more vitamin, and this figure is only going to get worse as the world moves towards plant-based diets.

People think that nutrient deficiency only affects people in underdeveloped countries – but it is also affecting the majority of women living in high-income nations."

Keith Godfrey, Professor of Epidemiology from the University of Southampton

The study, which was published in PLOS Medicine, assessed 1,729 women between the ages of 18 and 38 at conception and followed many during subsequent pregnancies.

It was undertaken by researchers from Southampton and its National Institute for Health and Care Research (NIHR) Biomedical Research Centre, the University of Auckland, National University of Singapore, and Agency for Science, Research and Technology, Singapore.

Results showed that nine out of ten women had marginal or low levels of folate, riboflavin, vitamins B12 and D around the time of conception, and that many developed vitamin B6 deficiency in late pregnancy.

Co-author Professor of Paediatric Endocrinology Wayne Cutfield, from the University of Auckland, said while folic acid is recommended for women planning conception and during pregnancy, expecting mothers should be given over-the-counter multivitamins to reduce nutrient deficiencies.

He added: "The wellbeing of a mother ahead of conceiving and during a pregnancy has a direct influence on the health of the infant, their lifelong physical development, and ability to learn."

The PLOS Medicine trial was the first to show that supplements, available over the counter, can reduce vitamin insufficiencies during the preconception, pregnancy and lactational periods.

Associate Professor Shiao-Yng Chan at the National University of Singapore said: "If we continue to move towards diets with less meat and dairy products, reducing intakes of micronutrients essential for a child's development, vitamin deficiencies will continue to grow unless women start taking more supplements or are supported with specific advice about nutrient-rich foods."