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Work Under Way

Question

What is the relationship between folic acid from supplements and/or fortified foods consumed before and during pregnancy and lactation and specific health outcomes?

Approach to Answering the Question
NESR Systematic Review

Subcommittee
Pregnancy and Lactation Subcommittee

Systematic Review Protocol
Developed for each scientific question being examined, the protocol describes the plan for how the systematic review was conducted. The protocol provides the: 

  • Analytic framework, 
  • Literature search and screening plan, and 
  • Literature search and screening results. 

See the full protocol for the question, what is the relationship between folic acid from supplements and/or fortified foods consumed before and during pregnancy and lactation and specific health outcomes? 

View Full Protocol

Draft Conclusion Statement

The draft conclusion statements listed below describe the state of the science related to the specific question examined. Draft conclusions are not considered final until they have been deliberated with and decided upon by the full Committee and published in the Committee’s final advisory report. Individual conclusion statements should not be interpreted as dietary guidance or the Committee’s overarching advice to the Departments. 

Pregnancy

Micronutrient Status

Strong evidence suggests that folic acid supplements consumed before and/or during pregnancy is positively associated with folate status (serum, plasma, and/or RBC folate). Grade: Strong 

Insufficient evidence is available to determine the relationship between folic acid from supplements consumed before and/or during pregnancy and hemoglobin, mean corpuscular volume (MCV), and serum vitamin B12. Grade: Grade Not Assignable

No evidence is available to determine the relationship between folic acid from supplements consumed before and/or during pregnancy and red cell distribution width (RDW). Grade: Grade Not Assignable

No evidence is available to determine the relationship folic acid from fortified foods consumed before and/or during pregnancy and micronutrient status. Grade: Grade Not Assignable

Gestational Diabetes

Insufficient evidence is available to determine the relationship between folic acid from supplements and/or fortified foods consumed before and during pregnancy and the risk of gestational diabetes. Grade: Grade Not Assignable

Hypertensive Disorders of Pregnancy 

Limited evidence suggests that folic acid supplements consumed during early pregnancy may have a beneficial effect on reducing the risk of hypertensive disorders during pregnancy among women at high-risk (e.g. history of preeclampsia or prepregnancy BMI ≥25 kg/m2) compared to no folic acid supplementation. Grade: Limited

Moderate evidence suggests that higher levels of folic acid supplements consumed during pregnancy compared to lower levels (including no folic acid supplementation) does not affect the risk of hypertensive disorders during pregnancy among women at low-risk. Grade: Moderate

No evidence is available to determine the relationship between folic acid from fortified foods consumed before and during pregnancy and the risk of hypertensive disorders during pregnancy. Grade: Grade Not Assignable

Human Milk Composition

No evidence is available to determine the relationship between folic acid from supplements or fortified foods consumed before and during pregnancy and human milk folate. Grade: Grade Not Assignable

Neurocognitive Development

Insufficient evidence is available to determine the relationship between folic acid supplementation before and/or during pregnancy and cognitive, language, and social emotional development, and risk of autism spectrum disorder in the child. Grade: Grade Not Assignable

No evidence is available to determine the relationship between folic acid from supplements consumed before and during pregnancy and movement/physical development, academic performance, anxiety, depression, or the risk of attention-deficit disorder (ADD) or attention-deficit/hyperactivity disorder (ADHD) in the child. Grade: Grade Not Assignable

No evidence is available to determine the relationship between folic acid from fortified foods consumed before and during pregnancy and developmental milestones including neurobehavioral development in the child. Grade: Grade Not Assignable

Lactation

Micronutrient Status

Moderate evidence suggests that folic acid supplements consumed during lactation alone is positively associated with RBC folate, and may be positively associated with serum/plasma folate. Grade: Moderate

Insufficient evidence is available to determine the relationship between folic acid from supplements consumed during lactation alone and hemoglobin, mean corpuscular volume (MCV), and serum vitamin B12. Grade: Grade Not Assignable

No evidence is available to determine the relationship between folic acid from supplements consumed during lactation alone and red cell distribution width (RDW). Grade: Grade Not Assignable

No evidence is available to determine the relationship folic acid from fortified foods consumed during lactation alone and micronutrient status. Grade: Grade Not Assignable

Human Milk Composition

Moderate evidence suggests that consumption of folic acid supplements during lactation alone does not influence folate levels in human milk. Grade: Moderate

No evidence is available to determine the relationship between folic acid from fortified foods consumed during lactation alone and human milk folate. Grade: Grade Not Assignable

Neurocognitive Development

No evidence is available to determine the relationship between folic acid from supplements or fortified foods consumed during lactation alone and developmental milestones including neurobehavioral development in the child. Grade: Grade Not Assignable