19229
The present study evaluated the effects of pica and IDA on oxidative stress and antioxidant capacity as well as on the levels of trace elements including serum zinc and selenium in 47 children with IDA plus pica , 22 children with IDA only and 21 nonanemic children as controls .
 zinc, selenium
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 zinc, selenium