Skip to main content

Large doses of folic acid lower your risk of preeclampsia

Large doses of folic acid lower your risk of preeclampsiaPreeclampsia is a serious pregnancy disorder with elevated blood pressure, proteinuria, and life-threatening complications in severe cases. It has already been reported that folic acid supplements help prevent preeclampsia in pregnancy. According to a new study that is published in Pregnancy Hypertension, taking even larger quantities of folic acid seem to offer additional protection. Unfortunately, many pregnant women forget to take folic acid supplements that are normally recommended as a way of avoiding spina bifida.

Preeclampsia normally occurs after the 20th week of pregnancy with symptoms such as elevated blood pressure and proteinuria. In severe cases, hemolysis (breakdown of red blood cells), low platelet count, impaired liver function, kidney failure, sleep disturbances, headache, chest pain, ankle swelling, and breathing difficulty may occur due to fluid retention in the lungs. There can also be elevated homocysteine levels in the blood that increases the risk of blood clots. If left untreated, this condition can lead to convulsions (eclampsia) where the expecting mother loses consciousness.
Preeclampsia is one of the most common causes of death in pregnancy. Women who have had the condition have an increased risk of heart disease and stroke later in life. The list of risk factors of preeclampsia includes overweight, previous problems with hypertension, old age, and diabetes. It looks as if lack of folic acid also plays a role.

  • Around 2-3% of all pregnant women get some degree of preeclampsia
  • Most of them do not have any symptoms and the condition is discovered in connection with a routine checkup
  • Preeclampsia is treated with anti-hypertensive medicine
  • In severe cases, labor is started

Large doses of folic acid make a difference in several ways

The researchers behind the new study already knew that folic acid supplementation is able to lower the risk of preeclampsia. They therefore wanted to investigate if taking even larger doses of folic acid before and during pregnancy could lower the risk even more. They carried out a randomized clinical study of 1,576 women, all of whom had had preeclampsia in connection with their last pregnancy and now planned to become pregnant again. The women were divided into two groups. One group got 0.4 mg (400 micrograms) of folic acid daily, which is the dose that is normally recommended for pregnancy. The other group got 4 mg, which is a ten-times higher dose but is not harmful in any way. By comparing the two groups, the scientists could see that the women in the high-dose group had:

  • Lower homocysteine levels in their blood
  • Fewer cases of hypertension
  • 50% reduced risk of preeclampsia

The researchers concluded that high doses of folic acid taken three months prior to conception and during the entire pregnancy can lower the risk of preeclampsia.

IMPORTANT: Folic acid deficiency during pregnancy may also result in serious

Pregnant women have an increased need for folic acid, which is necessary for making DNA during the growth and development of the fetus. Lack of folic acid may therefore disrupt normal cell division in the fetus and result in underdevelopment of the brain and cause spina bifida with the risk of severe disabilities, heart failure, and stillbirth.
It is therefore a problem that many pregnancies are not planned in advance and are discovered too late. Also, many pregnant women forget to take their folic acid supplements.

Deficiency and poor utilization of folic acid is caused by

  • Pregnancy
  • Unhealthy diets
  • Alcohol or substance abuse
  • Smoking
  • Poor nutrient absorption from the small intestine
  • Birth control pills
  • Methotrexate (drug for treating rheumatism and cancer)
  • Anti-seizure medication (Phenytoin)


Lili Zheng et al. The Effect of Folic Acid Throughout Pregnancy Among Pregnant Women at High Risk of Pre-Eclampsia: A Randomized Clinical Trial. Pregnancy Hypertension. 2020

Debra Sullivan. What to know about folate deficiency. Medical News Today 2019

Ernæringsrådet. Folsyre til kvinder, der planlægger graviditet – kun få følger anbefalingerne

  • Created on .