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Giving your child too much milk – for too long - can put babies at risk of iron deficiency

5 October 2007

Delay weaning your baby too long and you may be putting your child at risk of iron deficiency.

Delay weaning your baby too long and you may be putting your child at risk of iron deficiency. That’s the finding of Dr Pauline Emmett, head of nutrition research at the Children of the 90s project and David Hopkins, Paediatric Dietician at the Children’s hospital in Bristol.

They and their team of researchers analysed the diets of 928 children, looking back to when they were just eight months old. The team found that those babies who had continued to have large amounts of milk at 8 months of age did not progress with weaning solids and some ran the risk of iron deficiency.

The researchers confirmed that babies fed cows’ milk as a main drink run a higher risk of iron deficiency anaemia. Those fed cows milk at 8 months were 70% more likely to be anaemic by the time they were 12-months-old compared with those given formula milk.

Another important finding was that anaemia was also more likely in the infants who were breast-fed at 8 months. However this was related to not feeding enough iron-rich foods to the infant rather than the breast milk itself.

The joint research project involved David Hopkins, Paediatric Dietitian, Dr Pauline Emmett, Head of Nutrition Research at the University of Bristol’s Children of the 90s project and Children of the 90s Statistician, Colin Steer.

Dr Emmett said, “Cows’ milk contains large amounts of calcium and this prevents the absorption of iron from food. It is necessary to obtain iron from food in order to make red blood cells, anaemia occurs when not enough red blood cells are formed. Anaemia in infants can lead to slower mental development”. She added that cows' milk should be strongly discouraged as a main drink before 12 months.

David Hopkins added, “A higher proportion of those babies who had 6 or more breast feeds per day had low iron intakes and obtained almost a third less energy from solids than those having less than 6 breastfeeds.

“It makes sense that when you are trying to get a baby to take more weaning solids you should not be feeding large amounts of fluids that fill them up.

“It is important to introduce many and varied iron containing weaning foods at this stage. These would include breakfast cereals, meat, fish, vegetables and beans and pulses. Fruit is also important as it contains vitamin C which helps iron absorption. We have to get the balance right between giving babies the known benefits from breast milk and ensuring they progress to an adequate weaning diet and this research may go some way towards helping with that”.


David Hopkins, Pauline Emmett, Colin Steer, Imogen Rogers, Sian Noble, Alan Emond. Infant feeding in the second 6 months of life related to iron status: an observational study. Archives of Disease in Childhood; 2007: 92: 850-854 doi:10.1136/adc.2006.114074


Editors note:

  • ALSPAC The Avon Longitudinal Study of Parents and Children (also known as Children of the 90s) is a unique ongoing research project based in the University of Bristol. It enrolled 14,000 mothers during pregnancy in 1991-2 and has followed most of the children and parents in minute detail ever since.
  • The ALSPAC study could not have been undertaken without the continuing financial support of the Medical Research Council, the Wellcome Trust, and the University of Bristol among many others.


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