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Vitamin A may reduce skin cancer risk

March 9, 2012

According to a new US study, regular use of vitamin A supplements may reduce the risk of developing melanoma, especially in women.

In the observational study, 69,635 participants with an average age of 62 were examined for the develop-ment of melanoma and interviewed about their use of vitamin A supplements over the course of six years (1). The study results showed that participants who were currently taking a vitamin A supplement, and had done so regularly over the past 10 years, were about 40% less likely to develop melanoma than those who had never taken vitamin A supplements. These effects were more pronounced in women than men, and the protection was greater in body parts that were exposed to the sun.

According to the researchers, the results indicated that, in addition to sun protection, increased vitamin A intakes could help prevent melanoma. The effects were only seen in people who were taking more vitamin A than what is found in multivitamins. The protective effect might be stronger in women than men because men may be more susceptible to skin damage from ultraviolet radiation. However, the scientists cautioned that taking too much vitamin A could lead to harmful conditions, such as birth defects, liver problems and bone pain. It was not clear just how beneficial vitamin A might be. Further studies would be needed to clarify how much vitamin A would be necessary in supplements in order to boost melanoma prevention.

According to the U.S. National Institutes of Health, the recommended daily amount of vitamin A is
700 micrograms for adult women and 900 micrograms for adult men. Taking more than 2,800 micrograms of vitamin A per day could lead to toxic symptoms in adults. Vitamin A plays an important role in vision, bone health, immune function and reproduction. The vitamin is found in foods such as sweet potatoes, carrots, spinach, milk, eggs and liver. Surveys show that about 46% of Americans have insufficient intakes of
vitamin A (2).

Melanoma is the sixth leading cause of death in the U.S., according to the American Cancer Society. Based on recent estimates, about 76,000 cases of melanoma will be diagnosed this year. Reducing sunlight exposure is recommended to reduce the risk of melanoma. This includes limiting time in direct sunlight, wearing sun block and avoiding tanning beds. There is also a strong genetic component related to melanoma risk.

References

  1. Asgari M. M. et al. Association of Vitamin A and Carotenoid Intake with Melanoma Risk in a Large Prospective Cohort. Journal of Investigative Dermatology. Published online March 2012.
  2. Fulgoni V. L. et al. Usual intake of vitamin A, calcium, magnesium, phosphorous and potassium from NHANES (2003-2004). FASEB J. 2008; 22:1081.5.