Vitamin C intake, lead exposure, and oxidative stress in Uruguayan school children

Oxidative stress (OS) is a potential mechanism for lead (Pb) toxicity. Vit C may modify Pb‐induced OS. This study examined the relation between blood lead level (PbB) and OS markers [8‐isoprostane and 8‐hydroxy‐2‐deoxy Guanosine (8‐oxodg)], and the role of vit C intake in modifying the relation between PbB and OS. 6–8 y old children (n=145) from Montevideo, Uruguay were assessed in a cross‐sectional study, including nutrient intake via two 24 hr recalls. Mean±SD PbB was 4.5±2.1 μg/dL, with 29% children having PbB≥ 5 μg/dL. Specific gravity‐adjusted mean±SD urinary 8‐isoprostane and 8‐oxodg were 1.5±1.2 and 50±32.7 ng/mL, respectively. Mean±SD intake of vit C was 57±54 mg/d, with 23% of children not meeting recommended intake (RDA, 25 mg/d). Children with vit C intake below RDA had higher urinary 8‐isoprstane than children who met RDA (p<0.05). PbB was associated with 8‐isoprostane (β=0.1; p<0.05) even after adjusting for serum ferritin, and vit C and zinc intake. Children in the lowest tertile of vit C intake (<30 mg/d) and PbB above median (>;4.9 μg/dL) had 0.9 ng/mL higher 8‐isoprostane than those in the highest tertile of vit C intake (>;62 mg/d) and PbB below median (p<0.05). PbB was not associated with urinary 8‐oxodg. Low vit C intake and even modest elevation in PbB may predispose children to increased OS. Grant Funding Source : NIEHS Grant 4231251X1