Estimating the Serum Folate Concentration Associated With the Red Blood Cell Folate Threshold for Optimal Neural Tube Defects Prevention: A Population Based Biomarker Survey. (7th June 2021)

• Record Type: Journal Article
• Authors: Fothergill, Amy; Rose, Charles; Crider, Krista; Bose, Beena; Guetterman, Heather; Johnson, Christina; Jabbar, Shameem; Zhang, Mindy; Pfeiffer, Christine; Qi, Yan Ping; Williams, Jennifer; Bonam, Wesley; Finkelstein, Julia
• Is Part Of: Current developments in nutrition. Volume 5(2021)Supplement 2
• Page Start: 644
• Page End: 644
• Publication Date: 2021-06-07
• Subjects: Nutrition -- Periodicals; Nutritional Physiological Phenomena; Nutrition; Periodicals; Periodicals; Fulltext; Internet Resources; Periodicals; 612.3
• DOI: 10.1093/cdn/nzab045_026
• Languages: English
• ISSNs: 2475-2991

Abstract

Abstract: Objectives: To estimate the serum folate insufficiency threshold (sf-IT) corresponding to the red blood cell (RBC) folate insufficiency threshold for optimal neural tube defect (NTD) prevention. Methods: Participants were 977 women of reproductive age (WRA; 15–40y; not pregnant or lactating) from a population-based biomarker survey in Southern India. Venous blood samples were collected at enrollment. Plasma, serum, and red blood cells were centrifuged, processed, and stored < -80°C until batch analysis. Total vitamin B12 concentrations were measured via chemiluminescence; RBC and serum folate concentrations were measured using the World Health Organization-recommended microbiological assay. Vitamin B12 deficiency was defined as total vitamin B12 < 148 pmol/L. Folate insufficiency was defined as RBC folate < 748 nmol/L, the recommended calibrator-adjusted equivalent of the threshold for population optimal NTD prevention. A previously developed Bayesian model and the RBC and serum folate distributions in this population were used to estimate the sf-IT corresponding to the RBC folate insufficiency threshold for optimal NTD prevention, overall and by age, body mass index (BMI) category, HbA1c, anemia, and vitamin B12 status. Results: The overall estimated median sf-IT was 37.8 nmol/L (95% credible interval [33.8–43.3]). This threshold was lower in overweight WRA (BMI: ≥25.0 kg/m2: 32.0 nmol/L [27.3–40.2] vs. BMI < 25.0 kg/m2: 36.2 nmol/L [32.2–43.3]), and varied by age (< 25y: 61.3 nmol/L [44.3–111.8]; 25 to 35y: 35.7 nmol/L [30.8–43.5]; ≥35y: 30.8 nmol/L [26.9–37.2]). The sf-IT was lower in anemic WRA (32.9 nmol/L [28.5–40.1]) compared to non-anemic WRA (42.0 nmol/L [36.1–51.3]), and lower in WRA with elevated HbA1c (≥5.7% to < 6.5: 32.4 nmol/L [27.3–41.6]; ≥6.5%: 20.9 nmol/L [17.8–25.6]) vs. WRA with HbA1c < 5.7% (43.8 nmol/L, [37.5–53.7]). The median sf-IT was higher in WRA with vitamin B12 deficiency (72.1 nmol/L [52.0–126.0]), compared to women who were not vitamin B12 deficient (28.1 nmol/L [25.6–31.5]). Conclusions: The estimated sf-IT is dependent on anemia, elevated HbA1c, BMI, age, and vitamin B12 status. Funding Sources: Centers for Disease Control and Prevention; AF was supported by the National Institutes of Health #5 T32 HD087137.