Meta-analysisindependent cross-checkabstract only checked★ key study I-SUP-02 in-depth review

Folic acid and birth defects (Cochrane)

Effects and safety of periconceptional oral folate supplementation for preventing birth defects.

Overview

De-Regil LM et al.. Cochrane Database Syst Rev 2015 · PMID 26662928 · DOI 10.1002/14651858.CD007950.pub3

Folic acid lowered neural tube defects by about 69%.

Does the study support the specific claim? No · Methodological quality: high

Study explained simply

What did the researchers want to find out?: Folate and birth defects.
How was the study done?: Cochrane.
How many people, animals or samples were studied?: 7,391.
What was actually found?: Fewer NTDs.
How large was the observed effect?: RR 0.31.
What do the results mean in everyday life?: Take folic acid when planning pregnancy.
What does it say about Elawady's specific claim?: Contradicts C-SUP-10.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: Other anomalies.

Authors: De-Regil LM et al.
Journal: Cochrane Database Syst Rev
Year: 2015
Identifier: PMID 26662928 DOI 10.1002/14651858.CD007950.pub3
Verification: verified – PubMed efetch 2026-10-25
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: Luz Maria De‐Regil: I am a full time staff of the Micronutrient Initiative, an International NGO that supports research projects and large scale programmes to improve vitamin and mineral consumption among the most vulnerable populations. Juan Pablo Peña‐Rosas and Pura Rayco‐Solon: The World Health Organization gratefully acknowledges the financial contribution of the Bill & Melinda Gates Foundation, Micronutrient Initiative, the Centers for Disease Control and Prevention (CDC), the US Agency for International development (USAID), the Global Alliance for Improved Nutrition (GAIN) and Harvest Plus towards the work in the area of nutrition. Donors do not fund specific guidelines and do not participate in any decision related to the guideline development process, including the composition of research questions, membership of the guideline groups, conduct and interpretation of systematic reviews, or formulation of recommendations. Ana C Fernández‐Gaxiola: none known.

Effects and safety of periconceptional folate supplementation

Results: NTDs RR 0.31 (0.17–0.58), 6,708 births, high-quality evidence; recurrence RR 0.34 (0.18–0.64); effect not modified by dose ≥400 µg.
Absolute risks: not reported in abstract excerpt
Authors' conclusion: Folic acid has a protective effect against NTDs.

High.

High-certainty benefit.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	high
Risk of bias	low
Precision of results	moderate
Directness	direct
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable