It’s commonly known that vitamin D helps maintain strong bones, helps the body absorb calcium and can improve heart health. But a recent study indicates vitamin D — specifically, vitamin D3 — can even help reduce the risk of breast cancer.
Breast cancer is the most common non-skin type of cancer in women, and, the researchers of the study say, there has been progress in detecting and treating the disease. Although certain anti-hormonal therapies have been shown to reduce breast cancer risk, many patients do not complete these therapies due to the side effects. This study found that in some cases, vitamin D decreased the risk of breast cancer by 83%.
To understand how vitamin D can decrease the risk of breast cancer, let’s look at the role of vitamin D in the body.
What is vitamin D?
Vitamin D is a fat-soluble vitamin, meaning it can dissolve along with fatty foods and be absorbed in the fatty tissues of the body. It is naturally present in a few foods, like salmon and tuna, and is fortified in milk, orange juice, yogurt, eggs and cereal. Two forms of vitamin D exist, based on the source.
Vitamin D2 is present in plant sources — mushrooms that are grown in UV light, fortified foods and daily supplements. Vitamin D3 comes from animal sources — fish, fish oil, liver, egg yolk and butter, as well as from supplements. You also can get vitamin D3 through exposure to sunlight.
A lack of vitamin D can cause rickets in children and decreased mineralization in bone at any age, leading to curvature of the spine, frequent fractures, difficulty walking and muscle cramps.
Beyond bone health, vitamin D also helps regulate cells responsible for autoimmune functions and converts to a hormone that can turn genes on or off — letting those genes know when to make enzymes and proteins that help maintain health.
Vitamin D can help reduce breast cancer by:
- Controlling how quickly breast cells multiply
- Improving cell cohesiveness with other cells so they don’t grow out of control
- Inducing abnormal cells to go into a programmed death
- Reducing inflammation
Should you take vitamin D supplements?
Should you take vitamin D to reduce breast cancer risk? Making sure you have enough (but not too much) vitamin D can only be beneficial. Studies show that the ideal vitamin D level you should have in order to reduce your risk is 60-70 mg/mL.
To find out what the right amount is, have your baseline vitamin D level checked through a blood test. Most of us don’t get enough of this important vitamin, and one estimate is that one billion people in the world are vitamin D deficient or insufficient.
Once you know your level of vitamin D, if the level is not in the therapeutic target range, you can begin supplementing with 2,000 international units of vitamin D3 daily. You can find vitamin D3 supplements at your pharmacy or health store. After two to three months of supplementation, have your blood level tested again to make sure it’s at the therapeutic range.
While it is important to take enough vitamin D to stay well and gain additional health benefits, it’s also essential not to take too much. Excess vitamin D can lead to elevated calcium levels, mental status changes, increased thirst and urination, loss of appetite, vomiting and muscle weakness. It is rare to reach toxic levels of vitamin D with routine supplementation, but if you have a history of elevated calcium levels, talk with your doctor before adding more vitamin D to your diet.
Making sure you have enough (but not too much) vitamin D can only be beneficial.
Questions about vitamin D
As research continues on the therapeutic uses of vitamin D, we uncover more questions.
For example, when testing total levels of vitamin D in African Americans, the results may not be accurate because this population may have lower levels of proteins that bind vitamin D. Instead of testing total levels, checking levels of serum 25 hydroxy vitamin D may show more definitive results.
Unfortunately, those tests give inconsistent results and still need improvement. Until that time, if you are African American and are concerned about having enough vitamin D, talk with your doctor about developing a safe but effective therapeutic range.
Researchers also are looking at data that indicates vitamin D can reduce the risk of other diseases, including colon and prostate cancers, multiple sclerosis, asthma and autoimmune diseases. We continue to be excited and hopeful to find ways that vitamins can help the body protect itself from illness.