Vitamin D may extend the lives of people with colon and rectal cancer, according to a study published on Wednesday suggesting another health benefit from the so-called sunshine vitamin.
The researchers in the study, published in the Journal of Clinical Oncology, used blood samples to determine vitamin D levels of the patients, and they were tracked for an average of about 6-1/2 years.
Those in the highest 25 percent of vitamin D levels were about 50 percent less likely to die during the study from their cancer or any other cause compared to the patients in the lowest 25 percent of vitamin D levels. ~ Reuters, 19 June 2008
I have always thought Vitamin D is the vitamin most people pay less attention to. It has two major forms --- Vitamin D2 or ergocalciferol, and Vitamin D3 or cholecalciferol.
Nutritional sources include several types of fish like tuna, salmon, and mackerel. You can also get it from eating eggs and mushrooms.
The easiest way to get it is to expose yourself in the sun either during the early mornings or late afternoons when sunlight is not too intense to cause sunburn. Vitamin D3 is produced in the skin when exposed to sunlight. Ten to fifteen minutes of sun exposure twice a week is the recommendation.
Former President Corazon Aquino should try to get some sun to improve her chances of living longer. In the study mentioned above, colorectal cancer patients with higher plasma Vitamin D levels were shown to have improved survival rates. Other studies have shown that Vitamin D suppresses the proliferation of cancer cells.
On the prevention aspect, the editorial of the Journal of Clinical Oncology has these important considerations:
Based on the results presented in JCO, should colorectal cancer patients be advised to take vitamin D supplements?
For primary cancer prevention, Gorham et al propose intakes of 1,000 to 2,000 IU/d.
Should cancer patients consider similar intakes?
In light of the risk of hypercalcemia, the Institute of Medicine defines a tolerable upper intake level for vitamin D of 2,000 IU/d for adults, a level that can be achieved among users of multiple supplements. Toxicity due to hypercalcemia, which may also have a genetic component, has also been a limiting factor in clinical trials using calcitriol, the most potent form of vitamin D; these trials also suggest limited treatment success for prostate cancer.