Fig. 1. Plasma vitamin B₁₂ in 86 children with intestinal parasitosis, before and three months after treatment. Analysis showed a significant increase for Giardia lamblia, p = 0.045 (triangle) and Enterobius vermicularis, p = 0.004 (circle). No significant differences were found for Cryptosporidium parvum, p = 0.388 (square).