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RCOG statement on new study on maternal vitamin D levels in pregnancy

News 19 March 2013

A new study, published today in The Lancet, states that maternal vitamin D levels in pregnancy do not affect children’s bone health.

The study was part of long-term health research project from the Avon Longitudinal Study of Parents and Children (ALSPAC), also known as the Children of the 90s study, and assessed vitamin D levels in 3960 women throughout pregnancy. The bone mineral content (BMC), measure of bone health, of their child was then assessed at an average age of 9.9 years.

Researchers measured vitamin D levels in all trimesters of pregnancy and found that while levels were higher in summer months and lower among non-white mothers and those who smoked during pregnancy, overall there was no significant association between a mother’s vitamin D levels and her child’s BMC.

The researchers state that current NICE guidelines on antenatal care, which recommend that all pregnant and breastfeeding women should take a 10 microgram vitamin D supplement every day, may be overstating the importance of vitamin D supplementation.

Dr Tony Falconer, President of the Royal College of Obstetricians and Gynaecologists, said:

“We know that Vitamin D regulates the amount of calcium in the body, which helps to keep bones and teeth healthy, and low levels have been associated with problems relating to the baby’s bone formation and a higher risk of diseases such as rickets and osteoporosis in later life.

“Some women are more at risk of having low vitamin D levels, these women include those of south Asian, black African, black Caribbean, or Middle Eastern origin, women who have limited exposure to sunlight, obese women (pre-pregnancy BMI >30) and those who eat a diet particularly low in vitamin D. It is particularly important these women get their required dose.

“As healthcare professionals, it is our role to reinforce the importance for proper diet and nutrition during pregnancy and throughout a woman’s lifespan. It is important that at-risk women are informed, at their first antenatal booking, of the importance of adequate vitamin D during pregnancy and after, to maintain their own and their baby’s health.

“Further research is needed to look at vitamin supplementation including potential benefits, harms and optimal dosing.”


For further information, please contact the RCOG Media and PR team on +44 20 7772 6300 or email

For more information see the NICE antenatal care guidelines on vitamin supplementation or read the RCOG’s statement on vitamin D supplementation