Supplementary Material for: The <b><i>MTHFR</i></b> C677T Polymorphism Is Related to Plasma Concentration of Oxidized Low-Density Lipoprotein in Adolescents with Cardiovascular Risk Factors

<b><i>Aim:</i></b> The aim of this study was to investigate possible relationships among the A1298C (rs1801131) and C677T (rs1801133) polymorphisms in the methylenetetrahydrofolate reductase <i>(MTHFR)</i> gene and levels of homocysteine, vitamins B<sub>6</sub>, B<sub>12</sub>, folic acid and lipid profile, including oxidized low-density lipoprotein (ox-LDL), of adolescents at cardiovascular risk. <b><i>Methods:</i></b> We recruited 115 adolescents (10-19 years old), 58.3% (n = 67) female, from a public school in Brazil who underwent anthropometric, biochemical and genetic tests as well as food consumption evaluation. <b><i>Results:</i></b> An important prevalence of hyperhomocysteinemia (19.1%) and alterations in triacylglycerol (17.4%), total cholesterol (26.9%) and high-density lipoprotein (HDL) cholesterol (48.0%) concentrations were observed, as well as low vitamin B<sub>6</sub> concentrations (23.5%). The categorization of homocysteine concentrations into tertiles revealed significant differences in serum concentrations of folate, vitamin B<sub>12</sub> and HDL, waist circumference and intake of total and saturated fat among the tertiles. The presence of variant alleles regarding the <i>MTHFR</i> C677T polymorphism interfered with vitamin B<sub>6</sub> and ox-LDL cholesterol concentrations. There was a trend for higher waist circumference values in T carriers (C677T), but not in C carriers (A1298C). <b><i>Conclusions:</i></b> The <i>MTHFR</i> C677T allele was associated with higher plasma vitamin B<sub>6</sub> and ox-LDL compared to the CC genotype.