Improvement of serum folate status in the US women of reproductive age with fortified iodised salt with folic acid (FISFA study)

Abstract

Objective: Mandatory folic acid fortification of enriched grains has reduced neural tube defect prevalence in several countries. We examined salt as an additional vehicle for folic acid fortification. The primary objective was to examine the change in serum folate concentration after 1 month of consumption of fortified iodised salt with folic acid (FISFA) among women of reproductive age. The secondary objectives were to examine (1) the feasibility of implementing FISFA intervention and (2) the acceptability of FISFA. Design: We conducted a pre–post intervention study (January–April 2023). Participants received a FISFA saltshaker with the study salt (1 g of sodium chloride salt fortified with 100 mcg of folic acid) to use instead of regular table salt for 1 month. Serum folate was measured using the Elecsys Folate-III immunoassay method at baseline and 1-month endpoint. Change in serum folate was assessed using a two-tailed Wilcoxon signed rank test for paired samples. Setting: Metropolitan city, Southern USA. Participants: Non-pregnant, 18–40-year-old women who lived alone/with a partner. Results: Thirty-two eligible women consented to participate, including eleven non-Hispanic-White, eleven non-Hispanic-Black and ten Hispanic. Post-intervention, there was a significant increase in median serum folate concentration of 1·40 nmol/l (IQR 0·74–2·05; P < 0·001) from 24·08 nmol/l to 25·96 nmol/l in an analytical sample of n 29. An increase was seen in 28/29 (93 %) participants. Feasibility: 100 % study consent and compliance. FISFA acceptability: 25 d average use; 1·28 g average daily intake; 96·7 % and 90 % reported taste and colour of FISFA as highly acceptable, respectively. Conclusions: FISFA is an effective approach to increasing serum folate concentrations among women of reproductive age. Findings should be replicated in a larger study.