Vitamin D: Vital but out of reach for cancer patients

The summer months often bring plenty of sunshine and with them plenty of opportunity for the body to make vitamin D. At least that’s what a lot of people think. In fact, it is difficult for most people to get enough vitamin D each day, which is important because the body needs the nutrient to absorb calcium and promote bone health. In fact, vitamin D deficiency is a widespread problem worldwide, according to a 2015 article from the National Institutes of Health. This may be because the vitamin is not naturally available in most foods, or because getting what you need from the sun, its main natural source, may require excessive exposure to harmful UV rays that damage the skin. For many cancer patients, it’s hard to get enough vitamin D because treatments for the disease can make the skin more sensitive to sun damage. The concern is compounded because the benefits of vitamin D are especially important for many cancer patients.

“Vitamins, in general, are natural compounds that assist with various bodily functions, including metabolism, nerve function, and skin health. Vitamin D, in particular, helps provide immune support, bone strength and regulate calcium in the blood,” says Issam Alaouine. , a medical oncologist at our hospital in Tulsa. Dr. Alawin says that cancer patients who receive the recommended dose of vitamin D during treatment reduce their risks of osteoporosis and bone fractures, especially if their treatment regimen includes certain treatments, such as steroids or hormone blockers.

Get enough

However, it is not always easy to get an adequate amount. Natural sources of vitamin D are limited. Some people assume they can get the vitamin from the foods they eat, but the truth is that very few foods have enough to qualify as an adequate source. Dairy products generally have more vitamin D than other foods, but even cow’s milk, which has 400 IU of vitamin D per quart, doesn’t have enough when you consider that the recommended daily intake for most people It’s out of 600 IU, says Matt Reinhart, MS, RD, CSO, LD, who leads the dietician’s team in clinical oncology at our hospital in Tulsa. The sun is our main natural source of vitamin D, but it does carry the risk of damaging the skin. “Unless you’re a milk drinker and get a good amount of sunlight every day, you’re likely falling short of your vitamin D needs,” Rinehart says.

Vitamin D deficiency is even more difficult to combat in cancer patients who experience fatigue and other challenging side effects of cancer treatment. “Because of its side effects, many cancer patients prefer to stay home,” says Dr. Alaouine. “They may be too tired to be active outside, or they may feel cold from anemia and want to stay covered inside.”

Many oncologists also recommend that patients stay out of the sun to avoid skin reactions that can result from treatment. Photosensitivity, for example, is often caused by certain treatments, such as radiotherapy, photodynamic therapy, and chemotherapy drugs such as methotrexate (Folex ^® , Mixat ^® ), a drug commonly used to treat leukemia and lymphomas, and fluorouracil (Efudex ^® , Adrucil ^® ). ), a drug commonly used to treat colon cancer. The effects of photosensitivity can range from mild redness or small pigmented spots to painful blisters or peeling of the skin. “In all of these cases, vitamin D supplementation is recommended,” says Dr. Alawin.

Vitamin D test recommended

It’s a good idea for cancer patients to have their vitamin D levels tested once they are diagnosed with cancer, during treatment and after treatment ends regularly, says Reinhart. If a patient’s levels are below recommended values, your doctor or dietitian may recommend nutritional supplements. But it is important to know which supplements are safe and appropriate, and to know that these vitamins should be taken with food.

Vitamin D is a fat-soluble vitamin, which means that it dissolves in fats and oils digested with food and also does not dissolve when taken alone. “We see many patients who are already taking vitamin D supplements, but because no one is educating them about the fact that the nutrient is fat-soluble, they don’t take full advantage of it because they don’t take it with a meal,” says Reinhart. But being fat-soluble also means that vitamin D can build up in your blood if you eat too much of it, which means that taking a higher dose than your doctor or dietitian recommends can cause toxicity. “This is why frequent check-ups and follow-up are so important,” says Reinhart.

Experts agree that more research is needed to fully understand the effect of vitamin D on the body. Before taking any supplements, talk with your care team about whether they are right for you and if they interfere with your treatment.