But even the researchers caution that it is too soon to make any recommendations about taking extra vitamin A to reduce risk for melanoma. Vitamin A can be toxic in high doses.
Researchers analyzed melanoma risk among 69,635 people. Study participants were aged 62 on average. The researchers found that those participants who took vitamin A via supplements were about 40% less likely to develop melanoma than those who did not.
Only the supplements lowered melanoma risk, not vitamin A from food. Liver, eggs, and milk are rich in vitamin A. These effects were more pronounced in women than men. And this protection was greater in body parts that were exposed to the sun.
The findings appear in the Journal of Investigative Dermatology.
In 2012, about 76,250 new melanomas will be diagnosed, and about 9,180 people will die from this type of skin cancer, according to the American Cancer Society.
“It was definitely linked with supplements, not diet,” says study researcher Maryam Asgari, MD, MPH. She is a dermatologist and research scientist at Kaiser Permanente in Oakland, Calif. Asgari points out that the effects were only seen in people who were taking more vitamin A than what is found in multivitamins.
What’s more, it was only vitamin A, not other carotenoids, that were responsible for the lower skin cancer risk. Carotenoids are precursors to vitamin A. They include beta-carotene and lycopene.
“People who are concerned about melanoma should avoid sun exposure, practice sun protection, and get annual skin checks,” she says.
It is too soon to say whether adding a vitamin A pill on top of that makes sense. Other research has suggested that vitamin A may have a role in preventing melanoma.
Still, too much vitamin A can be dangerous. Serious risks can include liver toxicity and bone pain.
Vitamin A May Have a Role in High-Risk Individuals
Darrell S. Rigel, MD, is a clinical professor of dermatology at New York University.
His advice is to take a multivitamin that contains vitamin A. “There is no downside to this, but there are risks to overdoing vitamin A, including liver damage, dry skin, and hair loss,” he says.
Heidi Waldorf, MD, agrees. She is a dermatologist at Mount Sinai Medical Center in New York City. “It is not surprising to me that vitamin A may be protective against melanoma,” she says. “However, high doses of vitamin A can have serious side effects, including liver toxicity.”
That said, “This may be an option for patients at high risk for melanoma because of prior diagnosis or family history, but not for the general population,” she says.
People at high risk for melanoma also include those with fair skin, history of sunburn, and a lot of moles.