Published on October 12, 2018

GrassrootsHealth promotes health change through research. There are many research articles which conclude that vitamin D levels above 60 ng/ml (150 nmol/L) may significantly reduce your chance of getting breast cancer. Read about some of the research here.

After you have decided to use vitamin D to prevent breast cancer and a whole slew of other diseases, here are your three easy steps:


Test your vitamin D level

Why is this important? Because GrassrootsHealth has found, through our D*action members, that there is a big difference in how different bodies react to vitamin D.





What does this mean?

This means that two people, both taking the same amount of vitamin D each day, could have vastly different vitamin D levels. Believe me, if there was a certain amount that was both safe and would achieve recommended levels – that would be the answer. Unfortunately, there is not. Some people only need 2,000 IU/day and others need 18,000 IU/day to get to the same level!

The idea of testing was one of the first agreed upon goals from our panel of 48 scientists. From their research and studies, they knew there was no ideal supplement amount, and it certainly wasn’t the paltry 400 IU or 1,000 IU being thrown around on a number of public web sites.

While GrassrootsHealth trusted the 48 scientists (and really if you can get 48 people to agree on anything you have success) we set out to demonstrate, through research, that achieving blood levels in the range of 40-60 ng/ml (100-150 nmol/L) might decrease overall disease. It had never been truly tested and analyzed. We started D*action, a mechanism to test vitamin D levels at home, provide feedback/education for participants, collect data, AND report on outcomes.

Our data is from over 10,000 individuals who have tested and reported on their supplementation, food, weight, diseases, and overall health. We used this data to publish a paper in AntiCancer Research. The paper concluded that there is a vitamin D response curve that can be used to approximate vitamin D level by supplement amount, but that at any one point there is wide variability. (Simple explanation here)

So… test your level at home with the D*action or the Breast Cancer Prevention Project, or get it done through your doctor.


Get the exact number and know your target number.

Recent research has shown a serum level of 60 ng/ml helped prevent 80% of breast cancer (vs the 20 ng/ml commonly recommended).  Your doctor will likely say this is excessive. They will worry you will become hypercalcemic (what?!?!?!). That sounds serious! We will show you throughout Breast Cancer Prevention Month that this is the magic number; not 20 ng/ml (50 nmol/L) or 30 ng/ml (75 nmol/L), the numbers most doctors learned in medical school.

AND you need a number! If you test with your doctor, please learn more if they tell you, “Your vitamin D level is fine.” Get the number. It will be in nanograms per milliliter (ng/ml) in the United States, or nanomoles per liter (nmol/L) in most other countries.

Since the average vitamin D level for women in the US is about 29 ng/ml (72 nmol/L), let’s assume you are below 60 ng/ml at your first test. Use our vitamin D calculator to figure out how much intake you might need per day to get to 60 ng/ml if that is what you choose to do.

Another important point is that whatever regimen you choose, do it daily. You need daily vitamin D to really elicit change to the body for disease prevention. Please read this blog and the referenced scientific paper about daily dosing.


Test again in 3-6 months

Vitamin D levels don’t change over-night. You can think of it like a diet. Just because you go on a diet, doesn’t mean you will lose 20 pounds that first week. You can get on that scale daily or weekly, but it will be over months that real change is made.

Scientists say it takes a minimum of two months for the change in vitamin D practice to take hold in your body, so that would be the minimum testing time. Twice a year is fine if you do not have a current medical situation.



GrassrootsHealth Breast Cancer Prevention Research Documents
Download here

Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention
Cedric F. Garland, Dr., PH, FACE
Anticancer Research
Read Paper

The Role of the Parent Compound Vitamin D with Respect to Metabolism and Function: Why Clinical Dose Intervals Can Affect Clinical Outcomes
Bruce W. Hollis and Carol L. Wagner
Journal of Clinical Endocrinology & Metabolism
December 2013
Read Paper