(RxWiki News) Melanoma, one of the most common cancers affecting Americans, casts a shadow over people at risk for this disease. However researchers are finding new ways to lower melanoma rates.
A recent cohort study examining the use of vitamin A supplements provided evidence that may help researchers find ways to reduce melanoma rates among high-risk populations
"Taking multivitamins containing Vitamin A might reduce risk of melanoma."
The author of this study was Maryam Asgari, MD, a researcher with Kaiser Permanente, a non-profit managed care consortium headquartered in Oakland, California.
Dr. Asgari, also a clinical professor of dermatology at the University of California, San Francisco, worked with several other researchers from the University of Washington’s department of epidemiology to conduct the study with 69,635 participants throughout western Washington.
The participants were all Caucasians – who have a higher melanoma risk than other races – between the ages of 50 and 75. They provided information about their supplement use over the previous ten years on study questionnaires.
After the six-year period of the study, 566 participants had developed melanoma. Participants who took vitamin A supplements were 40 percent less likely to develop the disease than those who did not report taking this nutrient.
Cohort studies follow large populations with similar characteristics over a period of time, in this case people with a risk of developing melanoma.
The purpose of this cohort study was to find out what, if any, connection there was between vitamin A and carotenoid supplementation and melanoma rates over a period of several years.
Carotenoids are a class of plant pigments named after carrots that are responsible for making some plants appear orange, yellow or red.
Carotenoids fall into two groups. The first are pro-vitamin A carotenoids, which can be converted by the body into vitamin A. The second are non pro-vitamin A carotenoids which cannot be converted into vitamin A, but often they have other purposes in the body.
Both types of carotenoids, as well as vitamin A itself, have been shown to have protective effects against melanoma in laboratory studies.
In this study, however, carotenoid supplementation did not show any significant effect on melanoma rates among study participants, though the number of participants using these supplements was too low to see much of an effect in the study.
Though the results of this study would make vitamin A supplements a good idea, using vitamin A for the prevention of melanoma is something that should be monitored by a healthcare professional.
Vitamin A toxicity can be an issue, especially if a person supplements vitamin A in addition to having a diet rich in vitamin A containing foods.
Vitamin A toxicity can result in symptoms similar to liver failure or jaundice, such as yellowing of the skin, reduced liver function, vomiting and nausea, as well as other symptoms. Vitamin A toxicity is usually not life threatening, though chronic toxicity can result in liver damage.
Physicians can run blood tests to determine vitamin A levels as well as helping to monitor patients for symptoms of toxicity. If toxicity occurs, it can be dealt with by cutting back on vitamin A intake, usually by stopping supplementation all together.
Because of the risk of toxicity, people who are not in high-risk groups for developing melanoma, such as fair-skinned individuals with a family history of melanoma, should not use vitamin A as a preventative measure.
Even those in high-risk categories should use caution when using vitamin A in large amounts.
This observational study began in December of 2002 and followed the participants until December of 2007. Statistical analysis of the data continued until the acceptance for publication in December of 2011.
The study was published in the March 1, 2012 volume of The Journal of Investigative Dermatology. There were no reported conflicts of interest.
Information regarding the funding for this research was unavailable, but the authors acknowledge the National Institute of Arthritis Musculoskeletal and Skin Diseases and National Cancer Institute.