Steady-state red blood cell folate concentrations can be reached with 375-570 µg folic acid/day

Objectives:
The threshold for population-level optimal red blood cell (RBC) folate concentration among women of reproductive age for the prevention of neural tube defects has been estimated at 906 nmol/L. However, the dose-response relationship between folic acid intake and blood folate concentrations is uncharacterized. Therefore, this review article has been conducted.

Is there dose-response relationship between folic acid intake and blood folate concentrations?

Study design:
This review article included 23 articles for red blood cell folate and by 97 articles for serum/plasma folate.

Results and conclusions:
The investigators found in 17 studies red blood cell (RBC) folate concentration increased 1.78 fold [95% CI = 1.66 to 1.93] from baseline to steady-state at 375-570 µg folic acid/day and it took a median of 36 weeks of folic acid intake [95% CI = 27 to 52] to achieve steady-state red blood cell folate concentrations.

The investigators found for every 100 µg/day folic acid intake, serum/plasma folate concentrations increased 11.6% [95% CI = 8.4 to 14.9] from baseline to steady-state, over a median of 13 weeks [95% CI = 10 to 16].

The investigators concluded that there is a dose-response relationship between folic acid intake and changes in blood folate concentrations. At 375-570 µg folic acid/day, red blood cell folate concentrations increase 1.78 fold from baseline to steady-state, over a median of 36 weeks. For every 100 µg/day folic acid intake, serum/plasma folate concentrations increase 11.6% from baseline to steady-state, over a median of 13 weeks. These results can inform how much additional folic acid intake is needed among populations of women whose red blood cell folate concentrations are below the optimal threshold.

Original title:
Systematic Review and Bayesian Meta-analysis of the Dose-response Relationship between Folic Acid Intake and Changes in Blood Folate Concentrations by Crider KS, Devine O, […], Berry RJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356991/

Additional information of El Mondo:
Find here more information/studies about pregnancy and folaat (also called folic acid).