July 8, 2015

Director's Letter 


 How do you get what you want? MEASURE IT 

"You get what you measure."  I was recently working with a medical consortium which indicated that the current electronic health record (EHR) systems that are in vogue now are centered around cost, not value, of the clinic experience.  For example, the practitioner records things with billing codes: tests ordered, consultation type, prescriptions, and laboratory fees. While there may be questions about your blood pressure, weight, or overall health goals, there is no way to record these goals, nor is there a feedback mechanism for the patient to let them know how well they're doing.   


We at GrassrootsHealth are working on new systems to expand health outcome information for additional nutrients, and adding sections for individual goal setting and tracking.  The system will take your input as to what you think you'd like to measure to help you be the healthy person you want to be...  and, it will track attainment based on your input as well.

In our recent publication of Sunlight and Vitamin D: Necessary for Public Health, it was stated that  


"The current policy of sun avoidance is creating probable harm for the general population. Ignorance of the effects of portions of the solar spectrum at wavelengths longer than the ultraviolet is due mainly to lack of suitable measurement tools for cutaneous and systemic responses to those regions. We propose therefore that the U.S. Surgeon General's office, the World Health Organization, the Institute of Medicine, and other health entities, together or separately, engage in an immediate effort both to define and quantify comprehensively the benefits and harms of sun exposure and to develop the measurement methods needed for their detection and quantification."  


Please note the word 'define'. Currently, there is no agreed upon measurement for even what health effects we get from the sun's rays; there are only assorted research papers.  There are ongoing arguments about the harms and benefits of the sun without any measurement standards that we can all use in making determinations about exposure.  We will be working with the scientific community to help put those proposed measurement standards in place for consideration.  


Stay tuned for further development.  As noted above, you have to measure what you want to achieve, AND, you have to carefully define exactly what it is that you need to measure!  




Carole Baggerly 

Director, GrassrootsHealth

A Public Health Promotion & Research Organization

Moving Research into Practice NOW!

Measuring Vitamin D 


Why do we need vitamin D?

Every tissue in our bodies needs vitamin D and will not work at their optimal potential if we do not have enough. In its most recognizable forms, vitamin D deficiency produces rickets in children and osteomalacia (bone softening) in adults.

Long term deficiency and deficiency at critical stages of development are now understood to be associated with a vast array of chronic diseases, including osteoporosis, impaired immune competence, various autoimmune diseases (such as diabetes and multiple sclerosis), several cancers (breast, colon, lung, lymphoma and prostate, among others) high blood pressure, pregnancy complications and cardiovascular disease. Asking the body to deal with these disorders without adequate vitamin D is like asking a fighter to enter battle with one hand tied behind his/her back.

Our scientists recommend a vitamin D blood level (25(OH)D) between 40-60 ng/ml for disease prevention, see our disease incidence prevention chart:

Click on image to expand

What are the forms of vitamin D and what do we measure?

Depending on the context, "vitamin D" has different meanings. Most accurately and strictly speaking, vitamin D is the compound that we produce in our skin in response to UV exposure, the same compound that we take in orally when we take a vitamin D3 supplement; it is also known as cholecalciferol. This is the parent compound for other vitamin D metabolites that we sometimes refer to. Some vitamin D supplements are in the form of vitamin D2, or ergocalciferol, which is made in plants such as mushrooms, and alfalfa. When referring to a vitamin D blood test or level of vitamin D in the blood, most often, that is referring to the measurement of 25-hydroxyvitamin D (abbreviated as 25(OH)D, or also known as calcidiol), a metabolite of vitamin D3. Another metabolite that is sometimes measured, although much less frequently, is 1,25-dihydroxyvitamin D (abbreviated as 1,25(OH)2D, or also known as calcitriol).

While new information from Dr. Bruce Hollis indicates that keeping a steady supply of the parent compound, vitamin D3, in the system is important for many cellular functions, measurement of this form is impractical and costly. The best way to keep a steady supply of vitamin D3 is to make sure you have daily input through UV exposure and/or supplements.
Why is measurement important?

Why can't we say that, like other nutrients, you need a certain amount per day and be done with it? In part, it is because people absorb and use vitamin D differently. In this chart, with 3,667 samples, you can see a wide range of serum levels for any single intake amount. For example, with those who took 4,000 IU/day, serum levels were measured as low as 20 ng/ml (deficient!) and as high as 120 ng/ml.

Click to expand

Another way to look at it is by achievement of serum level. Using over 13,000 sample points from our data, we graphed the supplement amount with the average serum level. You see here that it could take anywhere from 1,000 IU/day - 10,000 IU/day to achieve 40-60 ng/ml.

Click to expand

Some factors that influence vitamin D levels include age, BMI, food exposure, and sun exposure. It is also thought that your body will need more vitamin D if it is in a disease-fighting state.

When should I test?

At the very least, we recommend a baseline serum level measurement for yourself and a follow up in about 6 months to make sure you have achieved your goals. If not, adjust your intake and test again in about 6 months.  Sometimes it takes 3 or more tests to finally figure out your own body's vitamin D performance.  From that point forward, testing should be done at a minimum of once a year, ideally in the early spring (late March, early April) when your vitamin D level is the lowest.  It's a good time to adjust to make sure you don't get too low.

What have we learned through D*action data?

As of this writing D*action has roughly 9000 participants, of which 64% are female. The median age of participants at the time of their first test is 54 years old and the average serum level of first tests is 44 ng/ml. This makes D*action an ideal cohort to study the incidence of certain medical conditions within a vitamin D replete community.

We have reported on this data in past newsletters, but some highlights have been:
  • Showing supplementation amount does not strictly determine vitamin D level
  • Approximating how much added supplementation is necessary to raise vitamin D levels (based on group averages)
  • Demonstrating that the IOM is off by an order of magnitude in its recommended dietary allowance for vitamin D
  • Showing serum levels greater than 50 ng/ml may provide additional reduction in breast cancer risk 
  • Reporting a 50% lower incidence rate of type 2 diabetes in a population with a median serum level of 41 ng/ml, as compared to the NHANES cohort with median serum level of 22 ng/ml
Test Now!


Video of the Week 


Vitamin D Measurement, the Key to Change

Michael F. Holick, PhD, MD

Boston University Medical Center

December 2014



Michael Holick Dr. Holick has made numerous contributions to the field of the biochemistry, physiology, metabolism, and photobiology of vitamin D for human nutrition. Holick has established global recommendations advising sunlight exposure as an integral source of vitamin D.  He has helped increase awareness in the pediatric and medical communities regarding vitamin D deficiency pandemic, and its role in causing not only metabolic bone disease, and osteoporosis in adults, but increasing risk of children and adults developing common deadly cancers, infectious, autoimmune, and other diseases. He has written more than 300 peer reviewed articles and edited or wrote 12 books including "The Vitamin D Solution," and is the recipient of numerous awards and honors, including the Linus Pauling Functional Medicine Award from the Institute for Functional Medicine.


This video is a shared talk between Dr. Michael Holick and Dr. Alexander Wunsch. For this spotlight, we recommend the first half of this presentation - minutes 0 to 28. Holick explains vitamin D deficiency, starting with an unusual case study. He then goes through many examples of vitamin D deficiency, from all over the world, both past and present, through charts and study data. He discusses different sources of vitamin D (food, sun, tanning beds, supplements) and their effectiveness. He explains what he recommends to his patients, both those that are diagnosed with vitamin D deficiency and as a standard recommendation. He explains how different body types react differently to vitamin D and dispels many vitamin D myths.   


This is a great video to watch after you have measured your vitamin D blood level, to understand both what your level means to your health and how to increase your level.   


Watch Video 


Editor's Letter 


There was one point that really hit me this week when watching Dr. Holick's video. He made the point that if you are vitamin D sufficient for many years it is typical for blood levels to level out within 40-60 ng/ml. I live in Southern California and get regular sun and I will have to say - I think this is happening in my case. I still need to be cognizant of my sun exposure and supplementation, but I don't see the fluctuation I used to see in my vitamin D blood levels.

But... the key is measurement. It is great to look back and see what the levels were, what they are now - and how they have changed over time. Only by taking those measurements can you truly gauge where you are.

Are you behind on your blood tests? When did you take your last one? Do you test at regular intervals, twice a year, as our scientists recommend? If not, please consider getting a test now. Don't put it off. This data can be crucial in your preventive health. And... by testing through D*action you are helping others by participating in a program that is helping solve the world-wide vitamin D deficiency epidemic.




Susan Siljander       

Marketing Director, GrassrootsHealth

A Public Health Promotion & 

Research Organization  

Moving Research into Practice NOW!
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Your participation in this project funds all the GrassrootsHealth research and promotion.

Clear information on vitamin D and pregnancy  


Announcing Nationwide Campaign - free blood tests for pregnant women in the United States
Read Announcement

Interview by Dr. Mercola
about Protect our Children NOW!

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D*certified Practitioners

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A comprehensive vitamin D tracking on your phone or iWatch


You put your information in once, then every time you pull out your phone wherever you are on earth, it tells you when you can make vitamin D and how much of it. 


New! Wear SunFriendŽ wristbands for Healthier + Safer Sun TimeŽ


SunFriend tracks real-time exposure to both UVA and UVB, and flashes when you reach optimal exposure. Waterproof, patented, scientific, customizable. GrassrootsHealth readers save $10 GH2015


Disease Incidence Prevention Chart

Updated 08/24/2012
A chart showing the required vitamin D serum levels for prevention of many diseases including cancers, falls, heart attacks and diabetes and several others.

View Now


The Role of the Parent Compound Vitamin D with Respect to Metabolism and Function: Why Clinical Dose Intervals Can Affect Clinical Outcomes 

Read Paper 


Serum Level vs. Intake

D*action data

Chart shows wide range of outcomes for every supplement level

View Chart 


Average Serum Level by Vitamin D Supplement Amount
D*action data
Chart shows wide range of supplementation to achieve 40-60 ng/ml
View Chart

Higher vitamin D serum levels may reduce breast cancer risk
D*action data
Poster presentation  


Higher vitamin D serum levels may reduce incidence of type 2 diabetes
D*action data
Poster presentation
View Chart


Video of the Week

Vitamin D Measurement, the Key to Change

Michael F. Holick, PhD, MD

Boston University Medical Center

December 2014


Watch video

D*action now available in New York State!



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