How vitamin D powers up a cancer-fighting gene

Some human studies have found no clear link between vitamin D and cancer protection, while others indicate an undeniable connection…

For example, studies have shown that people who live near the equator, with higher exposure to the sunlight that produces more of the “sunshine vitamin,” have lower incidences of certain cancers and even lower death rates.

In lab and mouse models, researchers have found that vitamin D slowed cancer progression. In a large-scale human study, people who took vitamin D each day had a 17 percent lower risk of ending up with advanced cancer spread throughout their bodies.

Thankfully, these hopeful signs have spurred continuing research, revealing what could be a “game changer for the field of vitamin D as it relates to cancer”…

The power of p53

Researchers in Japan conducted a randomized clinical trial that included 392 patients with digestive tract cancers, including colorectal cancer, who were followed for a median of 3.5 years.

During this study, the researchers took an especially close look at the p53 gene, which produces a protein that prevents cells from becoming malignant. In cancer, the p53 gene becomes mutated, and the mutated p53 protein helps the cancer to grow and become immune to cancer therapy. But some people have an immune system that produces antibodies to control the production and release of this mutated p53 protein.

In the study, participants whose immune system produced those antibodies had a 27 percent reduction in risk of relapse or death if they also took 2,000 IUs of vitamin D3 daily — compared with participants in the same subgroup who did not take vitamin D supplementation.

Participants whose immune systems did not produce the antibodies received no survival benefit from taking vitamin D.

In a commentary in JAMA Network Open on the study, Dr. Michael F. Holick, a professor at Boston University Chobanian & Avedisian School of Medicine, says these results support the conclusion that improvement in vitamin D status through vitamin D supplementation can be an effective strategy for improving survival outcomes of cancers, especially of the digestive tract.

“We now recognize that there are a variety of variables that can influence how vitamin D prevents and responds to cancer,” corresponding author Holick says in the piece. “For example, being at a normal weight and taking vitamin D improves your ability to survive cancer. Other factors include the patient’s genetic makeup and how the patient utilizes and breaks down vitamin D.”

Sun and diet aren’t enough

Holick says it’s important to recognize that most studies showing vitamin D3 supplementation improves cancer survival had patients taking at least 2,000 IUs of vitamin D3 every day. This amount helps get vitamin D concentrations above 30 ng/mL and is not reported to cause any toxicity.

He notes that this amount can’t be achieved from diet or sunlight alone.

“Although vitamin D is the sunshine vitamin you cannot get enough vitamin D from sun exposure unless you expose more than 20% of your body surface to sunlight almost daily like the Maasai and Hazda do in equatorial Africa,” Holick says.

Since vitamin D deficiency has been reported to be as high as 72 percent among cancer patients, it’s an especially good idea to add vitamin D3 to your daily routine if you’re a cancer sufferer or survivor. Even if you’re cancer-free, you still may want to check your vitamin D levels, given that roughly 1 in 3 Americans is deficient in the sunshine vitamin.

Make sure you choose a quality vitamin D3 supplement. My colleague Margaret Cantwell explains the key difference vitamin D3 has on immune system function that vitamin D2 does not, in this post.

Sources:

1. BU commentary: Vitamin D supplementation was found to improve more than 1.5 fold survival of cancers of the digestive tract including colorectal cancer in patients with a cancer fighting immune system — EurekAlert!

2. Effect of Vitamin D Supplements on Relapse or Death in a p53-Immunoreactive Subgroup With Digestive Tract Cancer — JAMA Network Open