In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: RESULTS : After adjustment for cardiovascular disease risk factors , type of diabetes medication used , duration of diabetes , and intakes of folate , vitamin E , and beta - carotene , the adjusted relative risks of total cardiovascular disease mortality were 1 . 0 , 0 . 97 , 1 . 11 , 1 . 47 , and 1 . 84 ( P for trend < 0 . 01 ) across quintiles of total vitamin C intake from food and supplements .
### Output Text:
RESULTS : After adjustment for cardiovascular disease risk factors , type of diabetes medication used , duration of diabetes , and intakes of <span class="chemical">folate</span> , <span class="chemical">vitamin E</span> , and <span class="chemical">beta - carotene</span> , the adjusted relative risks of total cardiovascular disease mortality were 1 . 0 , 0 . 97 , 1 . 11 , 1 . 47 , and 1 . 84 ( P for trend < 0 . 01 ) across quintiles of total <span class="chemical">vitamin C</span> intake from food and supplements . 