People who take vitamin A supplements have lower chance of developing the deadly skin cancer melanoma.
Although supplements of vitamin A called retinol could be a protective agent against melanoma, the overdose of it can result in serious side effects, researchers say.
“We found a protective effect from supplemental vitamin A, more than you would get from a multivitamin,” said lead researcher Dr. Maryam Asgari, a dermatologist and investigator at Kaiser Permanente Northern California, in Oakland.
She added that people should not be taking vitamin A in the hope it will reduce the risk of melanoma. “For us to really be able to recommend that, we would need a trial,” Asgari said.
“Based on these findings I wouldn’t recommend that the average person start taking vitamin A to prevent melanoma; more data needs to be obtained to make this recommendation,” she said.
The study was published online March 1 in the Journal of Investigative Dermatology. To convey the study, Asgari’s assistants collected data on almost 70,000 people participating in a study on vitamins and lifestyle in Washington state.
After about five years of follow-up, 566 people had developed melanoma, Drugs writes.Taking vitamin A supplements was associated with a significantly reduced risk of developing melanoma (by as much as 40 percent).
Gender and sun exposure may also be a factor in how retinol could prevent melanoma, the researchers claim. The protective effect of retinol was stronger among women and in areas of the skin exposed to the sun.
Vitamin A is included in foods such as liver, eggs and milk, and appears to have an effect on cell differentiation and growth, the researchers noted.
The recommendation for vitamin A for adults is 700 micrograms to 900 micrograms a day. Taking more than 2,800 micrograms a day can lead to birth defects, liver abnormalities, reduced bone mineral density and mental problems, the U.S. National Institutes of Health says.
Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City, said she doubts about the effectiveness of vitamin A supplements.
“I will say that based on data and research, using vitamin A on the skin has been helpful to protect against skin cancers,” she said.
However, she thinks that vitamin A in the diet also protects against skin cancer. “Diet is your number-one source,” she noted.
“Everything you put into your body has an effect on your skin. Your skin is another organ system that affects and reflects your other organ systems,” she explained.
“When you eat antioxidants, like vitamin A, you are supporting your skin in a direct way and you are increasing protection against [ultraviolet] radiation and repair cells after UV radiation,” Day said.
Unfortunately, not all melanoma is a result of sun exposure. There is also a strong genetic component, Asgari added. “Even the most vigilant sun-avoider is at risk, especially if they are fair-skinned, freckle easily and have red or blonde hair.”
However, Asgari said that it’s not clear how much vitamin A might bring a benefit. “We don’t know yet the optimal dosage,” she explained. “Further studies will clarify how much vitamin A in the form of a supplement would be of benefit for melanoma prevention.”