Researchers at Mayo Clinic have found a significant difference in cancer progression and death in chronic lymphocytic leukemia (CLL) patients who had sufficient vitamin D levels in their blood compared to those who didn’t.
In the Mayo Clinic study, published online in the journal Blood, the researchers found that patients with insufficient levels of vitamin D when their leukemia was diagnosed progressed much faster and were about twice as likely to die as were patients with adequate levels of vitamin D.
They also found solid trends: increasing vitamin D levels across patients matched longer survival times and decreasing levels matched shortening intervals between diagnosis and cancer progression. The association also remained after controlling for other prognostic factors associated with leukemia progression.
The finding is significant in a number of ways. For the first time, it potentially offers patients with this typically slower growing form of leukemia a way to slow progression, says the study’s lead author, Tait Shanafelt, M.D., a hematologist at Mayo Clinic in Rochester, Minn. “This finding may be particularly relevant for this kind of leukemia because although we often identify it at an early stage, the standard approach is to wait until symptoms develop before treating patients with chemotherapy,” Dr. Shanafelt says. “This watch and wait approach is difficult for patients because they feel there is nothing they can do to help themselves.” “It appears vitamin D levels may be a modifiable risk factor for leukemia progression. It is simple for patients to have their vitamin D levels checked by their physicians with a blood test,” he says. “And if they are deficient, vitamin D supplements are widely available and have minimal side effects.”
This research adds to the growing body of evidence that vitamin D deficiency is a risk factor for development and/or progression of a number of cancers, the researchers say. Studies have suggested that low blood vitamin D levels may be associated with increased incidence of colorectal, breast and other solid cancers. Other studies have suggested that low vitamin D levels at diagnosis may be associated with poorer outcomes in colorectal, breast, melanoma and lung cancers, as well as lymphoma.
Replacing vitamin D in some patients has proven to be beneficial, the researchers say. For example, they cite a placebo-controlled clinical trial that found women who increased their vitamin D intake reduced their risk of cancer development.
In this study, the research team enrolled 390 CLL patients into a prospective, observational study. They tested the blood of these newly diagnosed patients for plasma concentration of 25-hydroxyl-vitamin D and found that 30 percent of these CLL patients were considered to have insufficient vitamin D levels, which is classified as a level less than 25 nanograms per milliliter. After a median follow-up of three years, CLL patients deficient in vitamin D were 66 percent more likely to progress and require chemotherapy; deficient patients also had a two-fold increased risk of death.
To confirm these findings, they then studied a different group of 153 untreated CLL patients who had been followed for an average of 10 years. The researchers found that about 40 percent of these 153 CLL patients were vitamin D deficient at the time of their diagnosis. Patients with vitamin D deficiency were again significantly more likely to have had their leukemia progress and to have died, Dr. Shanafelt says.
“This tells us that vitamin D insufficiency may be the first potentially modifiable risk factor associated with prognosis in newly diagnosed CLL,” he says.
The study was funded by the National Institutes of Health, Gabrielle’s Angel Foundation for Cancer Research, the Henry J. Predolin Foundation, Vysis, Inc., and the Mayo Hematologic Malignancies Fund. The authors declare no conflicts of interest.
By Andrew Schneider
WASHINGTON (May 24) — Almost half of the 500 most popular sunscreen products may actually increase the speed at which malignant cells develop and spread skin cancer because they contain vitamin A or its derivatives, according to an evaluation of those products released today.
AOL News also has learned through documents and interviews that the Food and Drug Administration has known of the potential danger for as long as a decade without alerting the public, which the FDA denies.
The study was released with Memorial Day weekend approaching. Store shelves throughout the country are already crammed with tubes, jars, bottles and spray cans of sunscreen.
The white goop, creams and ointments might prevent sunburn. But don’t count on them to keep the ultraviolet light from destroying your skin cells and causing tumors and lesions, according to researchers at Environmental Working Group.
In their annual report to consumers on sunscreen, they say that only 39 of the 500 products they examined were considered safe and effective to use.
The report cites these problems with bogus sun protection factor (SPF) numbers:
- The use of the hormone-disrupting chemical oxybenzone, which penetrates the skin and enters the bloodstream.
- Overstated claims about performance.
- The lack of needed regulations and oversight by the Food and Drug Administration.
But the most alarming disclosure in this year’s report is the finding that vitamin A and its derivatives, retinol and retinyl palmitate, may speed up the cancer that sunscreen is used to prevent.
A dangerous additive
The industry includes vitamin A in its sunscreen formulations because it is an anti-oxidant that slows skin aging.
But the EWG researchers found the initial findings of an FDA study of vitamin A’s photocarcinogenic properties, meaning the possibility that it results in cancerous tumors when used on skin exposed to sunlight.
“In that yearlong study, tumors and lesions developed up to 21 percent faster in lab animals coated in a vitamin A-laced cream than animals treated with a vitamin-free cream,” the report said.
The conclusion came from EWG’s analysis of initial findings released last fall by the FDA and the National Toxicology Program, the federal government’s principle evaluator of substances that raise public health concerns.
EWG’s conclusions were subsequently scrutinized by outside toxicologists.
Based on the strength of the findings by FDA’s own scientists, many in the public health community say they can’t believe nor understand why the agency hasn’t already notified the public of the possible danger.
“There was enough evidence 10 years ago for FDA to caution consumers against the use of vitamin A in sunscreens,” Jane Houlihan, EWG’s senior vice president for research, told AOL News.
“FDA launched this one-year study, completed their research and now 10 years later, they say nothing about it, just silence.”
On Friday, the FDA said the allegations are not true.
“We have thoroughly checked and are not aware of any studies,” an FDA spokesperson told AOL News. She said she checked with bosses throughout the agency and found no one who knew of the vitamin A sunscreen research being done by or on behalf of the agency.
But documents from the FDA and the National Toxicology Program showed that the agency had done the research.
“Retinyl palmitate was selected by (FDA’s) Center for Food Safety and Applied Nutrition for photo-toxicity and photocarcinogenicity testing based on the increasingly widespread use of this compound in cosmetic retail products for use on sun-exposed skin,” said an October 2000 report by the National Toxicology Program.
FDA’s own website said the animal studies were done at its National Center for Toxicological Research in Jefferson, Ark.