Public Health Service researchers in the Netherlands measured the amount of B12 in the blood of nearly 3,000 pregnant women at their first pre-natal appointment at three months. They then measured how often babies cried after birth and for how long.
The babies of mothers whose blood contained the least amount of B12 at the three-month test were up to eight times more likely to cry for prolonged periods than those with the highest levels. On average, five per cent of mothers with low blood levels of B12 gave birth to babies who cried a lot while only about one per cent of women with the most B12 reported that their baby cried excessively.
“This study provides first evidence for an early nutritional origin in infant crying behavior,” wrote the researchers. “The results suggest infants born to women with a low B12 status during pregnancy are at a higher risk for excessive crying behavior in their first months of life."
The researchers defined excessive crying as an average of three hours a day in the past week.
Excessive crying may be due to mothers whose blood was low vitamin B12 giving birth to babies who do not have a fully developed nervous system, suggest the researchers.
The sleep hormone melatonin may not be released fully causing longer crying episodes than exhibited by babies whose mothers had high levels of B12.
Also a lack of B12 may reduce the brain’s production of myelin, which protects nerve cells, leading to more sleeplessness.
Brain and nervous system
Occurring naturally in red meat, fish and dairy products, vitamin B12 is known to help the development of the brain and nervous system in unborn children. In later life, the vitamin also helps prevent dementia, heart disease and fertility problems.
Pregnant women are advised to avoid liver, raw eggs, soft cheese and shellfish which all contain vitamin B12.
Vegetarians and vegans can be particularly vulnerable to vitamin B12 deficiency; a condition that leads to anaemia, tiredness, weight loss and constipation.
The researchers found no link between folate, another nutrient essential for brain development and crying.
Source: Early Human Development journal
Title: Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying
Authors:Geertje Goedhart, Marcel van der Wal, Manon van Ellsden and Gouke Bonsel.