Connect with others who understand.

sign up log in
Resources
About MyBCTeam
Powered By

Vitamin D and Breast Cancer: Benefits and Uses

Posted on July 15, 2021
Medically reviewed by
Todd Gersten, M.D.
Article written by
Anika Brahmbhatt

If you’re living with breast cancer, you may be curious whether your vitamin D levels affect the condition’s progression. “Has anyone had issues with vitamin D?” asked one MyBCTeam member. Another said, “I am taking a booster of vitamin D.”

It’s important to understand whether there are any connections between vitamin D intake and breast cancer and if you should do anything to evaluate whether you have enough vitamin D in your diet.

What Is Vitamin D?

Vitamin D is a nutrient that your body needs to make your muscles move, help your nerves send signals, and allow your immune system to fight off bacteria and viruses that can make you sick. Vitamin D is also important so bones can absorb the calcium they need to be strong and healthy.

There are two kinds of vitamin D: vitamin D2 and vitamin D3. Vitamin D2 is mostly found in plants, mushrooms, and yeast. Vitamin D3 can be found in oily fish and is also made in the body during sun exposure. Additionally, vitamin D3 is later converted to 25-hydroxycholecalciferol, which helps turn on and off the genes that allow vitamin D to carry out its function in the body.

According to the Cleveland Clinic, foods that are good sources of vitamin D include:

  • Beef liver
  • Fortified cereal
  • Fish (such as salmon, sardines, swordfish, and cod liver oil)
  • Egg yolks
  • Fortified milk and orange juice

Your body converts vitamin D into its active form, called 1,25-dihydroxyvitamin D — which is also known as calcitriol and can be found as a supplement. This active form of vitamin D can affect the cells involved in the immune system.

Is Vitamin D Deficiency Linked to Breast Cancer?

Research shows that having low levels of vitamin D may increase the risk of developing breast cancer. That’s because vitamin D may help control the normal growth of breast tissue cells.

There is more information about the link between vitamin D and breast cancer than there is for many other conditions, though vitamin D has been researched concerning several other cancers as well. Twenty different types of cancer, including colorectal, kidney, lung, and pancreatic cancer, have incidence rates that are inversely related to the concentration of serum vitamin D in one’s body.

There is research to support the idea that higher blood levels of vitamin D may be a protective factor for people undergoing breast cancer treatment. Researchers from the University of California, San Diego School of Medicine reported that “breast cancer patients with high levels of vitamin D in their blood are twice as likely to survive the disease as women with low levels of this nutrient.”

There is also evidence indicating that a lack of vitamin D may be associated with a poorer outlook for people who have already gotten a breast cancer diagnosis. A 2021 study noted that “compared to those with deficient vitamin D levels, patients with sufficient levels had significantly better survival outcomes.”

However, other studies have indicated that associations between vitamin D levels and breast cancer risk or prognosis do not prove causation. In other words, other factors besides vitamin D levels could account for the outcomes in individuals with breast cancer, and a cause-and-effect relationship between the vitamin and the condition has not been solidified.

Considering what the research indicates regarding vitamin D and breast cancer, you may be wondering if taking vitamin D supplements is right for you.

Should You Take Vitamin D Supplements?

Before starting a regimen of vitamin D supplements, check in with your doctor, who can test your levels of vitamin D serum. This can be done as a simple blood test during your regular physical. If your health care team determines that you do not have enough vitamin D, they may recommend supplements. However, keep in mind that you should only take the recommended amount because there is a risk of taking too much.

The Office of Dietary Supplements warns that too much vitamin D can cause nausea and vomiting, muscle weakness, confusion, pain, dehydration, and kidney stones, among other side effects. Vitamin D can also interact with some medications, so don’t start any supplementation plan before speaking with your physician.

Talk With People Who Understand

On MyBCTeam, the social network and online support group for people with breast cancer and their loved ones, members discuss the chronic nature of the disease. Here, more than 53,000 members from across the world come together to ask questions, offer advice and support, and share stories with others who understand life with breast cancer.

Have you investigated your vitamin D levels? Share your experience in the comments below, or start a conversation on MyBCTeam.

Posted on July 15, 2021
All updates must be accompanied by text or a picture.
Todd Gersten, M.D. is a hematologist-oncologist at the Florida Cancer Specialists & Research Institute in Wellington, Florida. Review provided by VeriMed Healthcare Network. Learn more about him here.
Anika Brahmbhatt is an undergraduate student at Boston University, where she is pursuing a dual degree in media science and psychology. Learn more about her here.

Related articles

The first targeted treatment for human epidermal growth factor receptor 2 (HER2)-positive breast ...

How Early-Stage HER2-Positive Breast Cancer Treatment Has Evolved

The first targeted treatment for human epidermal growth factor receptor 2 (HER2)-positive breast ...
HER2-positive breast cancer is often treated with targeted therapies that can specifically find a...

6 HER2-Positive Breast Cancer Treatments: What To Know

HER2-positive breast cancer is often treated with targeted therapies that can specifically find a...
If you’ve been diagnosed with HER2-positive breast cancer, the best treatment for you will depend...

Slideshow: 6 Facts About Treating HER2-Positive Breast Cancer

If you’ve been diagnosed with HER2-positive breast cancer, the best treatment for you will depend...
Metastatic breast cancer (MBC) is an incurable but treatable form of breast cancer. It’s also kno...

New Treatments for Metastatic Breast Cancer: Extending Life

Metastatic breast cancer (MBC) is an incurable but treatable form of breast cancer. It’s also kno...
Breast cancer clinical trials — also called research studies — are designed to find more effectiv...

6 Things You Should Know About Breast Cancer Trials

Breast cancer clinical trials — also called research studies — are designed to find more effectiv...
Lymphedema is a condition that can develop after breast cancer treatment. It causes fluid buildup...

Understanding Lymphedema and Breast Cancer Treatment

Lymphedema is a condition that can develop after breast cancer treatment. It causes fluid buildup...

Recent articles

In welcome news to many who are immunocompromised, the U.S. Food and Drug Administration (FDA) re...

Next COVID-19 Vaccine Booster Dose Approved

In welcome news to many who are immunocompromised, the U.S. Food and Drug Administration (FDA) re...
Nurse Support | Top 3 Questions | Conversation Guide | Maintenance Therapy Breast cancer treatmen...

7 Ways Your Breast Cancer Nurse Can Support You

Nurse Support | Top 3 Questions | Conversation Guide | Maintenance Therapy Breast cancer treatmen...
Nurses are an important part of your health care team as you undergo treatment for human epiderma...

5 Ways Your Nurse Can Help During HER2-Positive Breast Cancer Treatment

Nurses are an important part of your health care team as you undergo treatment for human epiderma...
The genetic changes found in your breast tumor influence your prognosis and help your care team r...

What Is HER2? Understanding Cancer Genetics and Life Expectancy

The genetic changes found in your breast tumor influence your prognosis and help your care team r...
​Most people with breast cancer will undergo tests to determine whether their cancer is HER2-posi...

FISH and IHC Testing for HER2: 7 Things To Know

​Most people with breast cancer will undergo tests to determine whether their cancer is HER2-posi...
Advances in treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer ...

Life After HER2-Positive Breast Cancer Treatment: 5 Ways To Stay Healthy

Advances in treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer ...
MyBCTeam My breast cancer Team

Thank you for subscribing!

Become a member to get even more:

sign up for free

close