New research from the Irish Cancer Society has found a potential link between vitamin D use and increased breast cancer survival.
The data of almost 5,500 breast cancer patients between the ages of 50 and 80 were analysed as part of the study.
It found that taking vitamin D supplements after diagnosis was associated with an increased survival rate of 20% compared to those who didn’t.
Head of Research at the Irish Cancer Society, Dr Robert O’Connor said: “Before rushing out to buy vitamin D supplements, we urge women with breast cancer to first talk to their medical team. Vitamin D use can cause health issues and each woman’s cancer is unique and will require personalised treatment.
“While this is an important preliminary study, the findings only show an association, and not causal link. We will only know if vitamin D supplementation should be recommended to improve breast cancer treatment outcome in the coming years when the results of clinical trials emerge.”
The research was led by RCSI researcher Dr Jamie Madden, under the supervision of Prof Kathleen Bennett, Associate Professor in Pharmacoepidemiology at RCSI Dublin.
Prof Bennett said: “Previous studies have found that higher blood levels of vitamin D, which can come from our diet, sunlight or supplements, is associated with increased breast cancer survival. Our study suggests that vitamin D supplementation might be useful for women diagnosed with breast cancer. Large clinical trials are already underway overseas to look into this further.”
While the findings are significant, the researchers did not have access to information on other measures from the women that could possibly impact their likelihood of better outcome. For example, increasingly studies are showing that moderate physical activity and maintaining a healthy diet can benefit a patient undergoing cancer treatment but this was not collected in this study.
The research also found vitamin D users to be younger on average, be less likely to smoke and have lower tumour stage and tumour grade progression compared to non-users, all factors more likely to be associated with better survival.
The findings were revealed as breast cancer researchers, survivors, and broadcaster Miriam O’Callaghan today launched ‘Cups Against Breast Cancer,’ an Irish Cancer Society fundraising campaign which aims to raise money for breast cancer research and support services.
Every year over 3,100 women are diagnosed with the disease in Ireland.