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: CONCLUSION : A high vitamin C intake from supplements is associated with an increased risk of cardiovascular disease mortality in postmenopausal women with diabetes .
### Output Text:
CONCLUSION : A high <span class="chemical">vitamin C</span> intake from supplements is associated with an increased risk of cardiovascular disease mortality in postmenopausal women with diabetes . 