RESUMO
INTRODUCTION: Folate deficiency is commonly reported in ß-thalassemia. Individuals heterozygous for ß-thalassemia may have higher folate requirements than normal individuals. OBJECTIVES: To document the concentration of serum total folate and its forms in ß-thalassemia heterozygote users (ß-TmU) and nonusers (ß-TmN) of 5 mg folic acid/d; to determine whether folic acid (FA) consumption from fortified foods allows beta-Tm patients, who do not take FA supplements, to meet their dietary folate requirements; and to investigate the association between higher serum unmetabolized folic acid (UMFA) and inflammatory cytokine concentrations. METHODS: Serum total folate and forms were measured in 42 ß-Tm (13 ß-TmU and 29 ß-TmN) and 84 healthy controls. The mononuclear leucocyte mRNA expression of relevant genes and their products and hematological profiles were determined. RESULTS: ß-TmU had higher serum total folate, 5-methyltetrahydrofolate, UMFA, and tetrahydrofolate (THF) compared with ß-TmN. The ß-TmN had lower serum total folate and THF than controls. Plasma total homocysteine (tHcy) was lower in ß-TmU compared with both ß-TmN and controls, while ß-TmN had higher tHcy than controls. ß-TmU had higher IL-8 than their controls while ß-TmN had higher IL-6 and IL-8 than their controls. ß-TmU have higher levels of serum total folate, 5- methyltetrahydrofolate, UMFA, and THF than controls. There was no association between UMFA concentrations and cytokine levels. CONCLUSIONS: Mandatory flour fortification with FA in Brazil may be insufficient for ß-TmN, since they have higher tHcy and lower serum total folate than controls. Furthermore, ß-TmN have higher IL-6 levels than ß-TmU. UMFA was not associated with inflammatory cytokine levels.