From
Laboratory Equipment:
Researchers at the Univ. of Leeds have shown that higher levels of
vitamin D may help improve survival for bowel and skin cancer patients.
The results of two studies published in the British Journal of Cancer and Journal of Clinical Oncology found people with higher levels of vitamin D--at the time they were diagnosed--were more likely to survive.
In the first study researchers at the Dana-Farber Cancer Institute monitored 1,017 bowel cancer patients for nine years.
Using information about UV-B and sunlight exposure, skin type, body-mass index, and vitamin D intake from food and supplements they estimated the amount of vitamin D in patients' blood at the time of diagnosis.
The results showed that those with higher vitamin D scores after being diagnosed with cancer were 50% less likely to die from the disease--compared to those with lower vitamin D scores.
"Our study shows that levels of vitamin D after colorectal cancer diagnosis may be important for survival," says Kimmie Ng, study author. "We're planning further research in patients with bowel cancer to see if vitamin D has the same effect, and to investigate how vitamin D works with molecular and genetic pathways in the cell to fight cancer."
The second study found that malignant melanoma patients with the lowest levels of vitamin D in their blood at the time they were diagnosed were 30% more likely to relapse from the disease than those with the highest levels.
The researchers from Leeds also found that patients who have higher levels of vitamin D at diagnosis have thinner tumors at diagnosis.
"It's common for the general public to have low levels of vitamin D in many countries," says Julia Newton Bishop, study author. "Melanoma patients tend to avoid the sun as sunburn is known to increase the risk of melanoma. We use sunshine to make vitamin D in the skin, so melanoma patients' levels of vitamin D may be especially low. Our results suggest that melanoma patients may need to get vitamin D by eating fatty fish or by taking supplements to ensure they have normal levels. But we're continuing to carry out research to find out the optimum level of vitamin D. There's some evidence from other health studies that high levels of vitamin D are also harmful--so we should aim for a normal level rather than a very high one."
Sara Hiom, director of health information at Cancer Research UK, says, "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."