7315
We assessed Co whole blood concentrations in four healthy adult male volunteers who ingested a commercially available Co supplement ( 0 . 4 mg Co / day ) for 15 or 16 days .
 Co, Co, Co
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Co, Co, Co