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.

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!