Background The World Health Organization recently released recommendations stating that red blood cell (RBC) folate concentrations should be above 400 ng/L (906 nmol/L) for optimal prevention of folate-sensitive neural tube defects (NTDs). The objective of this study was to determine the distribution of folate insufficiency (FI) (<906 nmol/L) and potential risk of NTDs based on RBC folate concentrations among nonpregnant women of child-bearing age in Guatemala. Methods A national and regional multistage cluster probability survey was completed during 2009 to 2010 among Guatemalan women of child-bearing age 15 to 49 years of age. Demographic and health information and blood samples for RBC folate analyses were collected from 1473 women. Prevalence rate ratios of FI and predicted NTD prevalence were estimated based on RBC folate concentrations comparing subpopulations of interest. Results National FI prevalence was 47.2% [95% confidence interval, 43.3–51.1] and showed wide variation by region (18–81%). In all regions, FI prevalence was higher among indigenous (27–89%) than among nonindigenous populations (16–44%). National NTD risk based on RBC folate concentrations was estimated to be 14 per 10,000 live births (95% uncertainty interval, 11.1–18.6) and showed wide regional variation (from 11 NTDS in the Metropolitan region to 26 NTDs per 10,000 live births in the Norte region). Conclusion FI remains a common problem in populations with limited access to fortified products, specifically rural, low income, and indigenous populations. However, among subpopulations that are most likely to have fortified food, the prevalence of FI is similar to countries with well-established fortification programs.

Introduction Information on folate and vitamin B12 deficiency rates in Guatemala is essential to evaluate the current fortification program. The objectives of this study were to describe the prevalence of folate and vitamin B12 deficiencies among women of childbearing age (WCBA) in Guatemala and to identify vulnerable populations at greater risk for nutrient deficiency. Methods A multistage cluster probability study was designed with national and regional representation of nonpregnant WCBA (15–49 years of age). Primary data collection was carried out in 2009–2010. Demographic and health information was collected through face-to-face interviews. Blood samples were collected from 1,473 WCBA for serum and red blood cell (RBC) folate and serum vitamin B12. Biochemical concentrations were normalized using geometric means. Prevalence rate ratios were estimated to assess relative differences among different socioeconomic and cultural groups including ethnicity, age, education level, wealth index and rural versus urban locality. Results National prevalence estimates for deficient serum (<10 nanomoles per liter [nmol/L]) and RBC folate (<340 nmol/L) concentrations were 5.1% (95% CI 3.8, 6.4) and 8.9% (95% CI 6.7, 11.7), respectively; for vitamin B12 deficiency (<148 pmol/L) 18.5% (95% CI 15.6, 21.3). Serum and RBC folate deficiency prevalences were higher for rural areas than for urban areas (8.0% vs. 2.0% and 13.5% vs. 3.9%, respectively). The prevalence of RBC folate deficiency showed wide variation by geographic region (3.2%–24.9%) and by wealth index (4.1%–15.1%). The prevalence of vitamin B12 deficiency also varied among regions (12.3% –26.1%). Conclusions In Guatemala, folate deficiency was more prevalent among indigenous rural and urban poor populations. Vitamin B12 deficiency was widespread among WCBA. Our results suggest the ongoing need to monitor existing fortification programs, in particular regarding its reach to vulnerable populations.