(RxWiki News) Many women who have faced breast cancer also face decreased odds of survival. Increasing concentrations of a vitamin in the blood might change those odds.
In 2012, about a half million women died of breast cancer. Many research studies have focused on whether vitamin D is helpful in preventing cancer. But few studies have looked at whether vitamin D helps to increase survival in women who have had breast cancer.
Recently published research showed that higher amounts of vitamin D in the blood were associated with an increased chance of survival in breast cancer patients.
"Ask your oncologist before taking any vitamin supplements."
The research was conducted by a team led by Sharif B. Mohr from the Naval Health Research Center in San Diego, CA.
The research team analyzed five previously published studies that looked at the association of vitamin D and survival after breast cancer.
Products of the metabolism of vitamin D by the body can be measured in the serum. The normal range of 25-hydroxyvitamin D in the serum is 30-80 ng/ml.
The five different studies measured the vitamin D metabolite, 25-hydroxyvitamin D, in the serum of a total of 4,443 study participants.
Survival of the participants was evaluated over periods of 5 to 20 years in the five studies.
Three of the five studies found that serum vitamin D metabolite concentrations over 30 ng/ml were associated with 40 to 60 percent lower odds of dying. These odds were compared to women who had vitamin D in the low ranges of less than 20 or less than 30 ng/ml, depending on the study.
Overall, the five studies showed that serum 25-hyroxyvitamin D concentrations over 30 ng/ml decreased the risk of death by about 50 percent.
“These studies suggest it might be prudent for patients with breast cancer to have their serum 25-hydroxyvitamin D measured and repleted (brought up) to concentrations in the normal range (30 to 80 ng/ml) pending the performance of a randomized controlled clinical trial,” the authors suggested.
According to Heidi A. Jordan, MD, oncologist on the medical staff of Baylor Regional Medical Center at Grapevine, "This study indicated that patients with breast cancer should consider having their 25-hydroxyvitamin D levels checked and should attempt to maintain them within the normal range.
Dr. Jordan, who was not involved in this study, told dailyRx News, "This needs to be confirmed in an appropriately randomized and controlled clinical trial, as the study may help to clarify whether the tumor is the potential cause of the lower vitamin D, or, rather, the 25-hydroxyvitamin D could potentially be an indicator of a higher risk breast cancer."
The authors remarked that the clinical trials might clarify whether the tumor is the cause of lower concentrations of vitamin D metabolites.
It may turn out that 25-hydroxyvitamin D could be an indicator for severity of cancer, instead of a factor that caused longer survival.
The study was published in the March issue of Anticancer Research.
Funding for the research was provided by the Penn State Cancer Institute of the Milton S. Hershey Medical Center in Hershey PA, through the Department of the Navy Bureau of Medicine and Surgery.
The authors declared no conflicts of interest.