Vitamin D supplements, if taken for multiple years, may add years of life to those with cancer.
In a recent study conducted at Michigan State University, researchers found that vitamin D, if taken for at least three years, could help people with cancer live longer.
In the study, which was presented at the American Society of Clinical Oncology annual meeting this month and published in the Journal of Clinical Oncology, the researchers looked at a population of almost 80,000 people with cancer with an average age of 68 years old and 10 randomized controlled trials. They focused on the use of vitamin D supplementation and its effects on cancer risk and death.
The authors found that vitamin D supplementation was associated with a significant reduction of cancer-related death compared to placebo.
Using the database search, the researchers found that those using vitamin D supplements for at least three years had a 13 percent reduced risk of death from all cancers in comparison to placebo effects.
Although these results are promising, compared with placebo, vitamin D didn’t show a reduction in cancer incidence. The benefits only came into play once cancer had already manifested.
Dr. Tarek Haykal, a lead study author and second-year internal medicine resident physician at Michigan State University and Hurley Medical Center in Flint, Michigan, said in a released statement, “Vitamin D had a significant effect on lowering the risk of death among those with cancer, but unfortunately it did not show any proof that it could protect against getting cancer.”
Although the initial data results are promising, experts caution against vitamin D’s widespread use and that more research is needed.
“While the data described are interesting, there needs to be more careful analysis of whether cancer-related mortality was decreased for all cancer types, or for specific diagnoses, age ranges, ethnicities, etc., before considering whether it should be used to lower global cancer mortality,” Joya Chandra, PhD, associate professor of pediatrics, epigenetics, and molecular carcinogenesis at the University of Texas-MD Anderson Cancer Center and co-director of MD Anderson’s Center for Energy Balance in Cancer Prevention & Survivorship, told Healthline.
Cancer is a leading cause of death in the United States, ranked second only to heart disease, according to the Centers for Disease Control and Prevention.
In 2018, there were more than 1.7 million new cancer cases diagnosed in the United States, with almost 610,000 people dying from the disease, reports the National Cancer Institute (NCI).
Globally, the burden of cancer is much greater. There were 14.1 million new cases in 2012 and more than 8.2 million cancer-related deaths.
Vitamin D is a fat-soluble vitamin. You can obtain it through supplements and diet, and the body produces it when ultraviolet rays from sunlight encounter the skin.
However, unless you’re getting around 15 minutes of sun exposure between 10 a.m. and 3 p.m. several times a week, you may not be getting enough for daily levels.
Vitamin D is known to promote calcium absorption in the gut and aid in adequate levels of calcium throughout the body to ensure appropriate bone growth and remodeling.
The Harvard University T.H. Chan School of Public Health notes that if you live north of the line connecting San Francisco to Philadelphia and Athens to Beijing, odds are you’re not getting enough vitamin D.
Dr. Wasif M. Saif, deputy physician-in-chief and medical director at Northwell Health’s Cancer Institute in New York, told Healthline, “It’s now generally accepted that vitamin D deficiency is a worldwide problem that affects not only musculoskeletal health but also a wide range of acute and chronic diseases.”
He notes that people with cancer are especially more at risk for developing low levels of vitamin D “due to renal or hepatic dysfunction, malabsorption, and lack of sun exposure due to decreased ambulation.”
The amount of daily supplementation of vitamin D is still a point of debate among doctors. In a report by the Institute of Medicine in 2010, the recommended amount of vitamin D for children and adults is 600 international units (IU) per day.
However, because of the increased safety profile of vitamin D, the upper limit of intake was changed from 2,000 to 4,000 IU per day. Even at this new level, there’s no good evidence of harm.
Although vitamin D is naturally found in the environment and is many times supplemented in food, the exact amount of vitamin D that’s necessary to protect against death is still unknown.
Despite this study showing results which could reduce death, Chandra says much work still needs to be done.
“The safety of giving vitamin D to people with cancer and making sure it doesn’t interfere with therapy is of utmost importance. There may be benefits for some cancer diagnoses, but not others,” she said.
A recent study found that people recovering from cancer had a lower risk of dying if they were taking vitamin D supplements. Experts say more research is needed to confirm the findings.
While vitamin D is found in nature and is often supplemented in foods, there’s still a global deficiency.
“An effective strategy to prevent vitamin D deficiency and insufficiency is to get sensible sun exposure, eat foods that contain vitamin D, and take a vitamin D supplement if recommended by your doctor,” Saif said.