Folic Acid–Fortified Iodized Salt and Serum Folate Levels in Reproductive-Aged Women of Rural India

Importance India has a disproportionately high prevalence of neural tube defects, including spina bifida and anencephaly (SBA), causing a high number of stillbirths, elective pregnancy terminations, and child mortality; India contributes a large proportion of the global burden of SBA. Thirty years after folic acid was shown to be effective in reducing SBA prevalence, only about one-quarter of such births are prevented globally through cereal grain fortification. Objective To determine the association of folic acid–fortified iodized salt with serum folate concentrations among nonpregnant and nonlactating women of reproductive age. Design, Setting, and Participants This nonrandomized controlled trial using a preintervention and postintervention design was conducted in 4 rural villages in Southern India from July 1 to November 30, 2022. All households in the villages agreed to participate in the study. Preintervention and postintervention serum folate levels were analyzed among study participants at baseline and after 4 months, respectively. Intervention Consumption of approximately 300 µg/d of folic acid using double fortified salt (folic acid plus iodine). Median serum folate concentrations were assessed at baseline and 4 months. Main Outcomes and Measures Change in median serum folate levels between baseline and study end point as the primary outcome of the study. Results A total of 83 nonpregnant nonlactating women aged 20 to 44 years (mean SD age, 30.9 5.1 years) were eligible for the study and provided serum samples for analysis at baseline and the end point of the intervention. The median serum folate concentration increased from 14.6 (IQR, 11.2-20.6) nmol/L at baseline to 54.4 (IQR, 43.5-54.4) nmol/L at end of study, a 3.7-fold increase from baseline to study end point. Two-tailed Wilcoxon signed rank test showed the median difference in preintervention and postintervention serum folate concentrations to be highly significant ( P lt; .001). The participants found the salt acceptable in color and taste. Conclusions and Relevance Use of folic acid–fortified iodized salt was associated with increased serum folate concentrations in women of reproductive age. This novel evidence can inform public health policy to accelerate SBA prevention. Trial Registration ClinicalTrials.gov Identifier: NCT06174883