Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation

Details

• Alternative Title:
  Am J Clin Nutr
• Personal Author:
  Chen, Meng-Yu ; Rose, Charles E ; Qi, Yan Ping ; Williams, Jennifer L ; Yeung, Lorraine F ; Berry, Robert J ; Hao, Ling ; Cannon, Michael J ; Crider, Krista S
• Description:
  Background:
  
  For women of reproductive age, a population-level red blood cell (RBC) folate concentration below the threshold 906 nmol/L or 400 ng/mL indicates folate insufficiency and suboptimal neural tube defect (NTD) prevention. A corresponding population plasma/serum folate concentration threshold for optimal NTD prevention has not been established.
  
  Objective:
  
  The aim of this study was to examine the association between plasma and RBC folate concentrations and estimated a population plasma folate insufficiency threshold (pf-IT) corresponding to the RBC folate insufficiency threshold (RBCf-IT) of 906 nmol/L.
  
  Methods:
  
  We analyzed data on women of reproductive age (n = 1673) who participated in a population-based, randomized folic acid supplementation trial in northern China. Of these women, 565 women with anemia and/or vitamin B-12 deficiency were ineligible for folic acid intervention (nonintervention group); the other 1108 received folic acid supplementation for 6 mo (intervention group). We developed a Bayesian linear model to estimate the pf-IT corresponding to RBCf-IT by time from supplementation initiation, folic acid dosage, methyltetrahydrofolate reductase (MTHFR) genotype, body mass index (BMI), vitamin B-12 status, or anemia status.
  
  Results:
  
  Using plasma and RBC folate concentrations of the intervention group, the estimated median pf-IT was 25.5 nmol/L (95% credible interval: 24.6, 26.4). The median pf-ITs were similar between the baseline and postsupplementation samples (25.7 compared with 25.2 nmol/L) but differed moderately (±3–4 nmol/L) by MTHFR genotype and BMI. Using the full population-based baseline sample (intervention and nonintervention), the median pf-IT was higher for women with vitamin B-12 deficiency (34.6 nmol/L) and marginal deficiency (29.8 nmol/L) compared with the sufficient group (25.6 nmol/L).
  
  Conclusions:
  
  The relation between RBC and plasma folate concentrations was modified by BMI and genotype and substantially by low plasma vitamin B-12. This suggests that the threshold of 25.5 nmol/L for optimal NTD prevention may be appropriate in populations with similar characteristics, but it should not be used in vitamin B-12 insufficient populations. This trial was registered at NCT00207558.
  
  
• Subjects:
  Adult Bayes Theorem Body Mass Index China Dietary Supplements Erythrocytes Female Folic Acid Folic Acid Deficiency Genotype Humans Methylenetetrahydrofolate Reductase (NADPH2) Neural Tube Defects Nutrition Therapy Population Health Preconception Care Pregnancy Reference Values Vitamin B 12 Vitamin B 12 Deficiency Young Adult

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• Keywords:
  Bayesian Folic Acid Neural Tube Defects Plasma Folate Red Blood Cell Folate Vitamin B-12
• Source:
  Am J Clin Nutr. 109(5):1452-1461
• Pubmed ID:
  31005964
• Pubmed Central ID:
  PMC7099800
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Volume:
  109
• Issue:
  5
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:4f56ffef396d039599910b895c53bb05ba3ceeba6286ad6aa9b3660e5b6bb8cbf5f8ea9269709e9e0063c3926bacd1002df49b1fb3d788f620c9e262335d6aef
• Download URL:
  https://stacks.cdc.gov/view/cdc/86189/cdc_86189_DS1.pdf
• File Type:
  [PDF - 1.05 MB ]