How Vitamin D Reduces the Risk of Cancer
Vitamin D, also known as the sunshine vitamin, is a group of fat-soluble secosteroids that have widespread actions throughout the body.
This vitamin is responsible for increasing intestinal absorption of calcium, iron, magnesium, phosphate and zinc.
It boosts the immune system, reduces inflammation, regulates numerous cellular pathways, promotes cell growth, supports neuromuscular functions and more.
Several recent studies show that vitamin D plays a crucial role in preventing and treating various cancers.
In a 2016 study published in PLOS ONE, researchers reported that higher levels of vitamin D – specifically serum 25-hydroxyvitamin D – are associated with a correspondingly reduced risk of cancer.
Maintaining the right level of vitamin D can help prevent at least 16 different types of cancer, including breast, colon, lung, pancreatic, ovarian, prostate and bladder cancers.
1. Vitamin D and Breast Cancer
Breast cancer is one of the most common types of cancer diagnosed in women worldwide.
A 2006 study published in Cancer Epidemiology, Biomarkers & Prevention reports the positive connection between vitamin D and breast cancer.
The study highlighted the anticarcinogenic effect of vitamin D due to its participation in regulating cell proliferation, differentiation and apoptosis in normal and malignant breast cells.
Plus, a prospective study published in Cancer Causes and Control in 2013 notes that low serum vitamin D levels in the months preceding diagnosis may predict a high risk of premenopausal breast cancer. In fact, the risk is three times higher in women who have extremely low serum vitamin D levels.
Another study published in Anticancer Research in 2014 suggests that patients suffering from breast cancer with high levels of the vitamin in their blood are more likely to survive the disease than patients with low levels.
This study included more than 4,000 patients with breast cancer and was conducted between 1966 and 2010. All patients were followed for an average of nine years.
This study says that 25-hydroxyvitamin D, a metabolite produced by the body from the ingestion of vitamin D, increases communication between cells by switching on a protein that blocks aggressive cell division.
This prevents tumor growth and keeps it from expanding its blood supply. This is the reason for better survival in patients whose vitamin D blood levels are high.
2. Vitamin D and Colon Cancer
Colon cancer, also referred to as colorectal or bowel cancer, is the third most common cancer in the United States.
An adequate amount of vitamin D in the body can help prevent and reduce the risk of this cancer. The sunshine vitamin helps regulate cell growth, fight inflammation and prevent cancer cells from spreading.
In fact, it has been found that colon cancer diagnosis and death rates are lowest in states with the highest mean solar radiation.
A 2004 study published in Cancer Epidemiology, Biomarkers & Prevention analyzed several studies and came to the conclusion that 1,25-dihydroxyvitamin D and its precursor, 25-hydroxyvitamin D, may aid in the prevention of colorectal cancer in older women.
Another 2011 study published in Cancer Prevention Research says that vitamin D may decrease colon cancer risk by improving differentiation and apoptosis and decreasing proliferation, invasiveness, metastatic potential and angiogenesis.
The study notes that it is even more significantly associated with reduced rectal cancer risk.
In a 2014 study published in Gut, researchers studied a group of immune system cells called T lymphocytes, or T cells, that can target tumor cells and limit their growth.
They found that a high plasma 25-hydroxyvitamin D level is associated with a lower risk of colorectal cancer with intense immune reaction, supporting a role of vitamin D in cancer immune prevention through tumor–host interaction.
Moreover, high vitamin D levels can improve response to chemotherapy and targeted anticancer drugs in patients with advanced colon cancer.
3. Vitamin D and Lung Cancer
Lung cancer is the second most diagnosed cancer in the U.S. Both men and women are affected equally and it causes about 27 percent of all cancer deaths, according to the American Cancer Society.
Regular sun exposure to help the body produce vitamin D can help lower the rate of lung cancer and resulting deaths. In fact, people living at higher elevations are less likely to suffer from this type of cancer.
Vitamin D helps block the growth of cancer tumors, thanks to a form of vitamin D called calcitriol that helps limit blood supply to a tumor, thus preventing it from spreading.
A 2008 study published in Cancer Epidemiology, Biomarkers & Prevention analyzed various studies and suggested that although there is no overall association between the 25-hydroxyvitamin D level and lung cancer risk, higher circulating levels of vitamin D in the body may help lower the risk.
Another study published in Anticancer Research in 2012 reports that vitamin D is converted to its active form locally in the lung, which in turn plays an important role in lung health.
In a recent 2015 study published in Cellular Physiology and Biochemistry, 453 research abstracts were studied and 12 papers published between 2006 and 2014 were considered for inclusion in the meta-analysis.
All studies provided adjusted risk estimates of lung cancer according to the levels of vitamin D.