People who spend more time outside have a better chance of surviving certain cancers, new studies suggest.
Those who had higher levels of vitamin D – produced by the body in the presence of sunlight -when diagnosed with colon cancer were 50 per cent more likely to survive than those with low levels, researchers found. A separate study also found that patients who had high levels of the vitamin when they were diagnosed with skin cancer were more likely to have thinner tumors.
Vitamin D, which is also present in a small number of foods, such as fatty fish, is thought to be important in protecting against a number of other conditions, including osteoporosis, diabetes, asthma, high blood pressure, depression and Multiple Sclerosis.
Earlier this year scientists cautioned that health warnings about the damaging effect of the sun could be causing vitamin D levels to drop.
Prof Kimmie Ng, from the Dana-Farber Cancer Institute, in Boston, who followed 1,017 patients with colon cancer, also called colorectal cancer, for around nine years, said: “Our study shows that levels of vitamin D after colorectal cancer diagnosis may be important for survival.
“We are now planning further research in patients with bowel cancer to see if vitamin D has the same effect, and to investigate how vitamin D works.”
The findings were published in the British Journal of Cancer and Journal of Clinical Oncology.
A second study found that skin cancer patients who had the lowest levels of vitamin D in their blood when they were diagnosed were almost a third more likely to relapse than those with high levels.
Prof Julia Newton Bishop, from Leeds Institute of Molecular Medicine, who led the study, said: “It’s common for the general public to have low levels of vitamin D in many countries.”
She added that skin cancer patients tended to avoid the sun as sunburn is known to increase the risk of the disease.
The findings suggested that they should increase their vitamin D levels by eating more fatty fish or taking supplements, she said.
Sara Hiom, from Cancer Research UK, said: “Both these studies support the theory that higher levels of vitamin D can improve the chance of surviving cancer.
The key is to get the right balance between the amount of time spent in the sun and the levels of vitamin D needed for good health. “But protection from burning in the sun is still vital.”