Fort Lauderdale, Fla. ? Before you reach for your morning vitamins, consider this: They may not be good for you.

An analysis of 47 studies involving more than 180,000 participants taking beta carotene, vitamin E and vitamin A indicates that rather than improving health, popping the pills may increase the risk of death.

The report appears in today’s issue of the Journal of the American Medical Association and was compiled by researchers with the Cochrane Collaboration, an international network of experts who conduct systematic reviews of published studies to determine whether current treatments are based on scientific evidence.

The researchers reviewed 68 studies, but sorted out results from the 47 they considered the most credible and found an overall 5 percent increased risk of death. Beta carotene was associated with a 7 percent increased risk; vitamin A, a 16 percent increase, and vitamin E, a 4 percent increase.

Vitamin C and selenium also were included in the analysis and no increased risk of death was found, according to Dr. Goran Bjelakovic, director of medical science at the Center for Clinical Intervention Research in Copenhagen. But people taking vitamin C didn’t necessarily live any longer than people who didn’t take the vitamin.

“Our findings contradict the findings of observational studies claiming that antioxidants improve health,” the researchers wrote. There is no evidence that vitamin C increases longevity, they said, and while selenium tended to reduce mortality, more study is needed to confirm the benefit.

The vitamin industry took issue with the methods used in the analysis and with the findings.

“Healthy consumers can feel confident in continuing to take antioxidants for the benefits they provide. This meta-analysis does nothing to change those facts,” said Andrew Shao, vice president of the Council for Responsible Nutrition, a Washington-based trade association representing ingredient suppliers and manufacturers in the dietary supplement industry.