Published on May 17, 2021

Women with long-term UV exposure found to have a lower risk of breast cancer, especially with diagnosis in older age

Breast, lung, and colorectal cancer account for 50% of all new cancer diagnoses in women and breast cancer accounts for 30% of these newly diagnosed cancer cases. It is also one of the most readily preventable cancers.

Research on breast cancer and vitamin D levels has shown that women with vitamin D levels at or above 60 ng/ml (150 nmol/L) had an 80% lower breast cancer risk compared to women with levels less than 20 ng/ml (50 nmol/L). Similar results have been found among women in the United Kingdom — an 83% lower breast cancer risk with vitamin D levels above 60 ng/ml. A 2019 meta-analysis by Song et al. analyzed data from 70 observational studies and found a 6% lower risk of developing breast cancer for every 2 ng/ml (5 nmol/L) increase in vitamin D blood levels.

If Higher Vitamin D Levels Can Decrease Breast Cancer Risk, Could More Sun Exposure Decrease Risk as Well?

Vitamin D is produced in the skin upon exposure to UVB, therefore, individuals who get more sunshine and exposure to UVB are known to have higher vitamin D levels compared to those who don’t. Since higher vitamin D levels are related to lower cancer risk, could the decreased risk of breast cancer also be seen among those who get more exposure to sunshine?

One study that aimed to answer this question, by Pedersen et al., included data from 38,375 Danish women, 70 years of age or younger, who had been diagnosed with breast cancer, and 191,875 controls who were breast cancer free. They looked at the employment history of all the women to see if there was a correlation between breast cancer incidence and long-term, occupational UV exposure. While they did not find any notable effect of occupational UV exposure for early onset breast cancer specifically (diagnosed before the age of 50), they did find a 17% decreased risk for late-onset cancer (diagnosed at 50 years or older) with longer duration of UV exposure (more than 20 years exposure, OR=0.83) and a 11% decreased risk with higher cumulative UV exposure (top 25% percentile of exposure, OR=0.89). Also, the researchers found a 15% decreased risk overall associated with longer duration of UV exposure (more than 20 years, OR=0.85) for all diagnosis ages combined.

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To summarize, this study found that long-term occupational UV exposure was associated with a reduced risk of late-onset breast cancer among Danish women, and that longer durations and higher amounts of UV exposure contributed to a further decreased risk.

Relationship Between UV Exposure and Breast Cancer Risk Confirmed with this Meta-analysis

A dose-response meta-analysis on UV exposure and breast cancer risk, by Yilun Li and Li Ma, aimed to quantify the relationship between the amount of UV exposure and breast cancer risk. They included six case-control studies and conducted a dose-response meta-analysis, with an additional analysis by age, sunscreen use, and limb coverage.

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The authors found a significant dose-response correlation between UV exposure and breast cancer risk such that women in the highest exposure groups had a 30% lower risk of breast cancer compared to women in the lowest exposure groups (OR=0.70, p<0.001). A significant dose-response relationship in women over 40 years of age was found which showed a breast cancer risk reduction of 10% for each increase of 1000 mW/m2 hours in the dose of sunlight.

Overall, this study saw a negative correlation between UV exposure and breast cancer risk, especially among women over 40 years of age; women who did not tan or who covered their arms and legs while in the sun also had a higher risk of breast cancer.

Be Sure to Get Your Vitamin D Levels into the Cancer-Prevention Range!

With almost 90% of the general population having vitamin D levels below the recommended 40-60 ng/ml (100-150 nmol/L), it is obvious that most people need more vitamin D. While most of us cannot achieve a vitamin D level of 40-60 ng/ml from sun alone, either due to our lifestyle, where we live, or other circumstances, we can certainly reach those levels with the right amount of supplementation.

Below is a guide for how much you might need, and who may need more. Your levels can be tested safely at home – order your home test kit today.

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By joining the GrassrootsHealth projects, you are not only contributing valuable information to our study, but you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it. Do you know what your status of vitamin D, omega-3s, and other essential nutrients is? Could your levels be improved? Test now to find out!

We now have a NEW GIFTING SERVICE that allows you to quickly send ‘Gift Cards’ to friends, family and coworkers who you consider might need immediate access to testing, and to Claim the Joy of Your Health TODAY. Give the gift today!

What does the Research Say about Vitamin D & COVID-19?

It’s TIME to start saving lives! If you can help PREVENT the majority of the death, it’s time! What’s it costing you/us not to take action NOW?

There is much published research that supports a clear link between vitamin D and COVID-19 showing that higher vitamin D levels are related to:

a decreased risk of testing positive for COVID-19

increased viral SARS-CoV-2 RNA clearance

better clinical outcomes among patients with COVID-19

less severe COVID-19 disease

decreased risk of death due to COVID-19

Be sure to educate yourself on the benefits and importance of vitamin D for immune health, and take steps to ensure you and your loved ones are getting enough.

You can review all of the COVID-19 and immune health information we have shared on this page.

How Can You Use this Information for YOUR Health?

Having and maintaining healthy vitamin D and other nutrient levels can help improve your health now and for your future. Measuring is the only way to make sure you are getting enough!

STEP 1 Order your at-home blood spot test kit to measure vitamin D and other nutrients of concern to you, such as omega-3s, magnesium, essential and toxic elements (zinc, copper, selenium, lead, cadmium, mercury); include hsCRP as a marker of inflammation or HbA1c for blood sugar health

STEP 2 Answer the online questionnaire as part of the GrassrootsHealth study

STEP 3 Using our educational materials and tools (such as our dose calculators), assess your results to determine if you are in your desired target range or if actions should be taken to get there

STEP 4 After 3-6 months of implementing your changes, re-test to see if you have achieved your target level(s)

Enroll in D*action and Build Your Custom Test Kit!