Almost All Women With Breast Cancer Are Also Vitamin D Deficient

February 24, 2023

We all know someone who’s been affected by breast cancer, so it shouldn’t come as a surprise that it’s the most common type of cancer worldwide. According to a 2022 review published in The Breast, breast cancer accounts for one in eight cancer diagnoses and resulted in a total of 2.3 million new cases in 2020. 

As common as this devastating cancer is, I hear very little in the news about its link to vitamin D status. And yet, up to 96%1 of the breast cancer population is also deficient in vitamin D, per a 2017 review published in Breast Cancer.

While we aren’t shocked that vitamin D is profoundly helpful in promoting breast health given its vast and impactful health benefits, we found this statistic too compelling to not explore further—especially considering vitamin D deficiency affects 29% of U.S. adults2.

The connection between vitamin D & breast cancer.

In a 2017 Tumor Biology systematic review and meta-analysis, VDR gene polymorphisms were found to increase breast cancer risk3. Researchers believe the link between vitamin D and breast cancer risk has to do with vitamin D receptor (VDR) genes4 and their function in mammary glands—which include regulating calcium transportation during lactation and milk production. 

How vitamin D sufficiency can help prevent breast cancer.

While research on the exact mechanisms and pathways of the sunshine vitamin’s effect on breast cancer are ongoing, evidence consistently shows a clear association between circulating vitamin D [i.e., 25(OH)D serum vitamin D levels] and breast cancer risk.

In a 2015 case-control study from Breast Cancer Research and Treatment, women deficient in vitamin D [i.e., with 25(OH)D levels below 20 ng/ml] had a 27% higher risk5 of breast cancer than women with sufficient vitamin D levels. But while clinical vitamin D sufficiency is defined as 25(OH)D levels above 30 ng/ml, other research indicates that higher levels provide greater protection against breast cancer risk.

Case in point: In one pooled analysis from Anticancer Research, a serum 25(OH)D level of 47 ng/ml was found to lower breast cancer risk by 50%6. This aligns with what mindbodygreen has found after speaking to leading endocrinologists, RDs, and longevity experts—a truly optimal vitamin D status of 50 ng/ml or higher is the goal for thriving health and well-being.

How to achieve & maintain truly optimal vitamin D levels.

Evidence suggests the average person needs to consume 5,000 IU of vitamin D3 per day to reach the goal serum level of 50 ng/ml. The problem? Food sources high in vitamin D don’t offer enough to help you achieve this goal (unless you’re drinking 50 glasses a milk a day, that is). 

And though it’s nicknamed the “sunshine vitamin,” most people aren’t able to get sufficient safe sun exposure to achieve optimal vitamin D status due to myriad factors (e.g., age, latitude, season, climate, skin tone, biological sex, to name a few). 

The most effective way to reach and sustain optimal serum vitamin D levels is by taking a high-quality supplement that delivers 5,000 IU of vitamin D3 (bonus points if it features built-in healthy fats for enhanced bioavailability). Hint: You can find mindbodygreen’s all-time favorite vitamin D supplement selections here.

The takeaway.

A whopping 96% of the breast cancer population is also deficient in vitamin D. Science shows that achieving vitamin D sufficiency (specifically, serum levels of 47 ng/ml or higher) can help cut your breast cancer risk in half. 

To reach and sustain vitamin D sufficiency, experts suggest you increase your vitamin D3 intake to 5,000 IU per day. For a simple and effective way to get adequate vitamin D on a daily basis, consider a premium supplement.