Cancer Treatment Centers of America

Why vitamin D matters for cancer patients

Vitamin D is an important part of a healthy diet. It helps promote a healthy immune system, and being insufficient in this vitamin can compromise immune function.

For people faced with a cancer diagnosis, vitamin D may help prevent tumors from developing new blood vessels. Vitamin D also affects cell growth, by encouraging healthy cells to grow and discouraging the growth of cancerous cells.

Roughly 70 percent of the American population is low in vitamin D, according to Kristen Trukova, a nutritionist at our hospital near Phoenix.

Why vitamin D matters

In addition to controlling abnormal cell growth in cancer patients, vitamin D provides many other benefits that improve overall health. Adequate levels of vitamin D help support the following important functions in the body:

  • Bone health – Vitamin D helps your body absorb calcium and phosphorus, which promote strong bones.
  • Muscle function – People with a vitamin D deficiency experience muscle weakness, reduced athletic performance and are at greater risk for falls. The good news is, repletion of vitamin D has been shown to decrease falls and improve muscle strength and balance.
  • Cardiovascular function – It is believed that vitamin D protects cardiovascular health by reducing cytokines (inflammatory molecules) and by reducing cholesterol buildup in the arteries. It also may balance blood pressure by maintaining kidney hormone balance.

Vitamin D has also been linked to decreased risk of certain diseases, such as:

  • Diabetes – Since vitamin D increases insulin secretion, adequate vitamin D levels can improve insulin receptor responses.
  • Autoimmune diseases such as multiple sclerosis, type 1 diabetes, Crohn’s disease, lupus and rheumatoid arthritis – Research is less clear in these areas, but associations have been found between lower vitamin D levels and an increased risk of these autoimmune disorders.

How to know if you’re getting adequate vitamin D

A simple blood test from your doctor can check vitamin D levels. If you are interested in getting your levels checked, ask for the 25(OH)D test. There is debate over what level of vitamin D is considered adequate. In recent years, several studies have shown that higher vitamin D can cause heart disease or other forms of cancer. According to Trukova, the normal range for adequate vitamin D is between 30-100ng/mL.

“Once a patient gets above 30ng/mL, we want them to maintain in that area. Our goal is adequate, because it is still unclear what is optimal, or what is too much,” says Trukova.

Studies of vitamin D in relation to cancer

A study done by Trukova and her team found that stage IV prostate cancer patients with an adequate level of vitamin D had an improved survival rate after nearly two years compared with patients with an inadequate level of vitamin D.

According to Trukova, it’s important to exercise caution, but there is good evidence that vitamin D is essential for overall health and for cancer patients in particular. Although studies have shown a positive link between vitamin D levels and cancer risk, more well-designed clinical trials are needed, according to the American Cancer Society.