Vitamin D and Fish Oils Are Ineffective for Preventing Cancer and Heart Disease
The largest study to test vitamin D and omega-3 pills in healthy adults found they did little to prevent cardiovascular disease, but hinted at benefits for groups including African-Americans.

In recent years, many Americans have embraced vitamin D and fish oil pills, their enthusiasm fueled by a steady trickle of suggestive research studies linking higher levels of vitamin D with lower rates of cancer and other ills, and fish consumption with reduced heart disease.