Too much folate and B12 linked to increased autism risk

It is nothing new to us that folic acid and vitamin B12 are essential nutrients during pregnancy. For many types of vitamins, excess amounts are flushed out by the body. However, new research tells us this may not be the case for folic acid and B12.

“This research suggests that this could be the case of too much of a good thing,” says lead author Ramkripa Raghavan, MPH, MSc, a DrPH candidate in the Department of Population, Family and Reproductive Health at the Bloomberg School.

Why is B12 and folate important during pregnancy?

Vitamin B12 (cobalamin) and vitamin B9 (folate) are vital for the health of our nervous system. They promote cell growth and are essential in the development of your baby’s neural tube, brain and spine. When B12 is combined with folic acid, it can help to prevent spina bifida and other central nervous system birth defects in your baby.

B12 is also important in the synthesis of DNA and production of red blood cells. Without sufficient B12, you may develop anemia.

Vitamin B12 can be found in fish, poultry, eggs, cheese and fortified cereals. Folate can be found in fortified cereals, lentils, nuts, spinach and peas. 

How can too much folate and B12 be harmful? 

A new research study from the Johns Hopkins Bloomberg School of Public Health found that when a woman has a very high level of folate (4 times the adequate amount) right after giving birth, the child’s risk of developing autism spectrum disorder doubles. High levels of B12 also tripled the risk of the child developing the disorder.

It was found that when both B12 and folate levels were extremely high, the risk that a child develops autism spectrum disorder increases by 17.6 times.

Autism spectrum disorder is a neurodevelopmental condition characterized by social impairment, abnormal communication and repetitive or unusual behaviour. 

Researchers of this study are still unclear about why the combination of excessive levels of folate and B12 cause this problem. But they suspect that women with very high levels of folate and B12 may process these nutrients differently or have taken too much of these nutrients, or both.

The Bottom-Line

More research still needs to be done on excessive levels of folate and B12, but folate and B12 are still undoubtedly essential nutrients for a healthy pregnancy. Pregnant women should continue to take their prenatal supplements and aim for an adequate intake of folate and B12 during their pregnancy.

As a general guideline, pregnant women should keep to the recommended dosage of prenatal supplements, and have a balanced diet that consists of meat, fruits, vegetables and wholegrains.

If you are concerned about the levels of folate and B12 in your body, you should approach your doctor who can conduct a simple blood test and provide you with appropriate feedback.