COcoa Supplement and Multivitamin Outcomes Study

The purpose of this study is to determine whether taking daily, dietary supplements of cocoa extract (containing cocoa flavanols and theobromine from the cocoa bean) and/or a standard multivitamin reduces the risk of developing cardiovascular disease (including heart attack, stroke, coronary revascularization, unstable angina or acute coronary syndrome (ACS) requiring hospitalization, carotid artery surgery, and peripheral artery surgery or angioplasty, and cardiovascular mortality) and cancer.

Inclusion Criteria: 1. Women ≥ 65 years of age participating in the Women's Health Initiative (WHI) Extension Study. 2. Men ≥ 60 years of age and women age ≥ 65 years of age who were contacted for but not randomized into the VITAL trial. 3. Other women ≥ 65 years of age and men aged ≥ 60 years of age who responded to targeted mass mailings and volunteers who learned about the trial through the media or through ResearchMatch.org, an electronic recruitment website. 4. Willing to participate, as evidenced by providing informed consent and completing all required baseline forms. Exclusion Criteria: 1. History of myocardial infarction or stroke. 2. Diagnosed with invasive cancer other than non-melanoma skin cancer in the last 2 years prior to enrollment. 3. Any serious illness that would preclude participation and/or completion of the trial, including the diagnosis of kidney failure and current dialysis treatment. 4. Taking cocoa extract or multivitamin supplements and not willing to forego use during the trial. 5. Taking total supplemental vitamin D \> 1,000 IU/day and not willing to forego use during the trial. 6. Taking total supplemental calcium \> 1,200 mg/day and not willing to forego use during the trial. 7. Extreme sensitivity to caffeine. 8. Consume \< 75% of the expected number of both types of supplements during the run-in phase. 9. Unable to communicate in English due to language barrier or mental incapacity.