An interesting piece of new research has highlighted a link between low vitamin B12 status during pregnancy and a baby’s likelihood to cry often in the first few months after birth.

Public Health Service researchers in the Netherlands looked at vitamin B12 status of nearly 3000 women at their first pre-natal appointment. They then measured how often babies cried after birth and for how long.

It was found that babies born to mothers with the lowest blood levels of vitamin B12 were up to eight times more likely to cry for long periods than those with the highest levels.  The researchers wrote:

This study provides first evidence for an early nutritional origin in infant crying behaviour.  The results suggest infants born to women with a low B12 status during pregnancy are at a higher risk for excessive crying behaviour in their first months of life."

Three proposed mechanisms behind this finding are:

1. Vitamin B12 plays an important role in nervous system development and function.  It is proposed that ‘infant crying behaviour’ may be a result of babies being born without a fully developed nervous system.
2. Vitamin B12 is known to influence melatonin levels – babies born to mothers with adequate B12 may release more of this sleep-inducing hormone and therefore calm more quickly.
3. Lack of B12 may reduce the production of myelin, a protective layer around nerve cells.

My comments on this study:

Vitamin B12 is found in significant levels in animal products such as beef, pork, chicken, liver, kidneys, mussels, oyster, sardines, salmon, other fish, eggs, milk, cheese and brewers yeast.  NOTE: Pregnancy women are advised to avoid soft cheese, raw egg, raw seafood, liver products and oysters.

Most pregnancy multivitamin formula contain Vitamin B12. A healthy diet during pregnancy should include regular intake of protein, including the appropriate foods outlined above. 

Vegans are at risk of B12 deficiency and may wish to look at supplementation or fortified foods whether pregnant or not.  Some vegetarians, depending on their intake of eggs or dairy produce, may also benefit from additional B12. 

Antacid use during pregnancy

Vitamin B12 requires good levels of stomach acid and intrinsic factor to be absorbed in the digestive tract.  Many things may affect stomach acid production, including stress, zinc deficiency and the bacteria  Helicobacter pylori. 

Heartburn is a common issue experienced by pregnant women and antacids are often used to address this.  Unfortunately, antacids neurtralise stomach acid and therefore, will also affect levels of intrinsic factor.  Regular antacid use is likely to impact not only B12 absorption but also iron absorption - another mineral deficiency which is common during pregnancy.

This means that even a great diet packed with iron and vitamin B12 may not be absorbed well if coupled with regular antacid use.

Goedhart, Van der Wal et al.  Maternal vitamin B12 and folate status during pregnancy and excessive infant crying. Early Human Development Journal Volume 87, Issue 4, Pages 309-314 (April 2011)