Low Vitamin D Levels Linked to Advanced Cancers
Study Shows Three-Fourths of Cancer Patients Have Low Levels of Vitamin D
Vitamin D Supplementation
As a second part of the study, the researchers treated patients with low vitamin D levels with 50,000 international units (IU) of vitamin D a week for eight weeks. The recommended dietary allowance of vitamin D for most people is 600 IU a day, but much higher doses are often needed for the short-term treatment of vitamin D deficiency. This type of treatment should only be done under a doctor's supervision.
The average vitamin D levels of the supplemented patients rose to about 35 ng/mL -- in the normal range.
Now the patients have to be followed for months and years to see if vitamin D supplements appeared to reduce the chance of cancer spread and extend lives, Churilla says.
Phillip Devlin, MD, a radiation oncologist at Harvard Medical School, tells WebMD that such a study does not show cause and effect, only an association between low vitamin D levels and stage III cancer.
Churilla agrees. It could be that people with stage III cancer are more likely to have low vitamin D levels because they are sicker and don't eat as well or get out in the sun as much as people with less advanced cancer, he says.
Devlin says the study generates interesting ideas that need to be tested in larger, longer studies.
"We do not recommend vitamin D supplementation for cancer patients at this point," he says.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.