Keeping track of your vitamin D levels has a number of potential benefits. The nutrient helps boost your immune system and promotes the growth of healthy cells. It is critical in developing and nourishing strong bones. It helps foster muscle strength and agility. And some studies suggest that vitamin D may reduce your cancer risk. But, depending on your diet and where you live, you may be vitamin D deficient and not even know it. "We are having a 'silent epidemic' of vitamin D deficiency across the country," says Dr. Eugene Ahn, Medical Director of Clinical Research at our hospital near Chicago.
The connection between vitamin D levels and cancer is still unclear. But several studies published this year have linked vitamin D deficiencies with the behavior of cancer cells. Researchers at Stanford Medical Center, for example, concluded that in their study on lab mice, breast cancer cells grew faster and were more likely to metastasize in mice with low levels of vitamin D. "People at risk for breast cancer should know their vitamin D levels and take steps to correct any deficiencies," Stanford’s Dr. Brian Feldman tells ScienceDaily.com. Another study at Northwestern University suggests that low levels of vitamin D in men being treated for prostate cancer may signify a more aggressive form of cancer.
It’s important to know your vitamin D level before and during cancer treatments, Dr. Ahn adds. Much is still unknown about how the vitamin may affect treatments, such as immunotherapy, "but given the basic science and the relative safety of vitamin D, I recommend vitamin D replacement as a key component of integrative cancer care," Dr. Ahn says.
So what can you do to increase your vitamin D? Consider turning to good sources of vitamin D, which include:
Sunlight: The sun helps turn the body into a vitamin D factory. Skin exposed to ultraviolet rays produces vitamin D3, which is processed into vitamin D. But be careful. You don't need prolonged exposure to the sun to produce vitamin D. And it only takes a few minutes for the sun to do damage that could lead to skin cancer. In fact, the American Academy of Dermatology recommends not getting vitamin D from the sun.
Fish and mushrooms: Silver-scaled fish, such as cod and mackerel, are good sources of vitamin D. Mushrooms are a great vegetable source. Eggs and many other popular breakfast choices, when fortified, such as milk, yogurt, cereal and orange juice also may help. But it is difficult to get enough vitamin D from food alone.
Supplements: Taking your vitamin in pill form may be recommended if you have deficient levels of vitamin D and may be an efficient way to fix a deficiency, Dr. Ahn says.
Doctor Ahn also has an important word of caution. "Excessive levels of vitamin D may cause kidney stones," he says. "So no matter your strategy, it is important to talk to your doctor about your levels."
Learn more about the benefits of vitamin D.