Dried blood spot microbiological assay indicates high prevalence of folate deficiency in rural adult men and women in the Haitian Central Plateau

Abstract

Background Although folate deficiency is linked to adverse health effects, limited data exist characterizing the problem in rural settings. This study determined the prevalence of folate deficiency and anemia in rural adults in the Haitian Central Plateau using combined laboratory methods. Methods Dried blood spots (DBSs) and hemoglobin measurements were collected from adult men and women selected by cluster random sampling in Haiti’s Central Plateau. DBSs were analyzed for folate using a microbiological assay. Hemoglobin levels were determined using both a HemoCue photometer and the sodium lauryl sulfate microplate method. Red cell folate (RCF) levels were determined by normalizing DBS folate to hemoglobin. Results Of the 197 subjects assessed for hemoglobin, 11.4% of males and 21.0% of females were anemic (male: hemoglobin<12 g/dL; female: hemoglobin<11 g/dL). Of the 173 subjects assessed for RCF, 27.9% of men and 14.9% of women were folate deficient (RCF<340 nmol/L). Among reproductive-age women, 83.6% had RCF levels associated with a risk of neural tube defects of >14 per 10 000 live births (RCF≤699 nmol/L). Conclusions Adults in the Haitian Central Plateau suffer from high rates of anemia and folate deficiency, putting the population at elevated risk for disease. DBSs and microbiological assay make folate evaluation feasible, even in low-resource regions.

Dried blood microsample-assisted determination of vitamins: Recent developments and challenges

“…Red blood cell folate (RCF) is recommended to assess the long-term folate status (74). Shreckengost et al determined the hemoglobin (Hb) content of a DBS using the sodium laurylsulfate (SLS) microplate method (75,76). Consequently, folate concentrations may be expressed as Hb folate (HF) (nmol/g) by dividing the DBS whole blood folate concentration by the measured Hb concentration.…”