Michigan State University physicians have found that vitamin D, if taken for at least three years, could help cancer patients live longer. The findings suggest that the vitamin carries significant benefits other than just contributing to healthy bones and were presented at the American Society of Clinical Oncology annual meeting 2019.
In the US, cancer is the second leading cause of death, according to the US Centres for Disease Control and Prevention. “Vitamin D had a significant effect on lowering the risk of death among those with cancer, but unfortunately it didn’t show any proof that it could protect against getting cancer,” said Tarek Haykal, a lead author on the study and an internal medicine resident physician at Michigan State University and Hurley Medical Centre in Flint, Michigan.
The researchers looked at data related to disease prevention from more than 79,000 patients in multiple studies that randomly compared the use of vitamin D to a placebo over at least a three-year period. Haykal and his team zeroed in on any information that involved cancer incidence and mortality.
“The difference in the mortality rate between the vitamin D and placebo groups was statistically significant enough that it showed just how important it might be among the cancer population,” Haykal said.
While these findings show promise, Haykal cautioned that the exact amount of the vitamin to take and what levels are needed in the blood are still unknown. He also said that it’s unclear how much longer vitamin D extends lifespan and why it has this result.
“There are still many questions and more research is needed,” Haykal said. “All we can say is that at least three years of taking the supplement is required to see any effect.”
Results show enough promise, however, that Haykal would like to see more doctors, especially oncologists, prescribe vitamin D to patients in general.
“We know it carries benefits with minimal side effects, he said. “There’s plenty of potential here.”
Background: In the United States cancer is the second leading cause of mortality, as such, primary prevention of cancer is a major public health concern. Vitamin D supplementation has been studied as a primary prevention method for multiple diseases including cardiovascular disease, osteoporosis, diabetes mellitus and cancer. The role of aspirin as primary prevention of cancer is still controversial. With fast emergence of large randomized controlled trials (RCTs) in that regards, we aimed to evaluate the efficacy of Vitamin D supplementation as primary prophylaxis for cancer.
Methods: A comprehensive electronic database search was conducted for all RCTs where comparison of Vitamin D supplementation versus placebo for the prevention of any type of disease with at least 3 years of Vitamin D supplementation was used and where cancer incidence or mortality was reported. The primary outcome was cancer-related mortality and cancer incidence. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) using a random-effects model at the longest follow-up.
Results: We included 10 RCTs with 79,055 total patients, mean age of 68.07 years, a female percentage of 78.02% and a minimum follow-up of 4 years and more. Vitamin D was associated with significant reduction of cancer-related mortality compared with placebo (RR 0.87; 95% CI: 0.79-0.96; P = 0.05: I2= 0%). Compared with placebo, Vitamin D was not associated with significant reduction of cancer incidence (RR: 0.96; 95% CI: 0.86-1.07; P = 0.46; I2= 31%).
Conclusions: Our study highlights that the use of Vitamin D supplementation for primary prevention of cancer is important as it does decrease cancer-related mortality once cancer is diagnosed, however it has no role or effect on cancer incidence.
Varun Samji, Tarek Haykal, Yazan Zayed, Inderdeep Gakhal, Vijaysai Veerapaneni, Michele Obeid, Babikir Kheiri, Sunil Badami, Ghassan Bachuwa, Rizwan Danish