August 5, 2015

Director's Letter 


Diabetes--do you have it?

It affects over 9% of our total population, 25.9% of seniors 65 and older. The CDC expects the number of cases to double or triple in the next 40 years. Is this necessary?

Our latest paper, just published with YOUR Data, shows a full 60% lower rate of incidence of type 2 diabetes with our median serum level of 41 ng/ml vs.the NHANES median of 22 ng/ml.  Another very significant finding was that the data were consistent with previous data we have published showing a sigmoidal response curve with the serum level, and not a straight line:

  • there is a flat (no) response for people under 10 ng/ml
  • between 10 ng/ml and 30-35 ng/ml, there is a very definite positive clinical response and
  • no additional effect above 30-35 ng/ml
A very significant addition to the field with the GrassrootsHealth data is that we actually have enough people above 35 ng/ml to demonstrate this plateau.  Prior to this publication, it was not clear.  Thank you! 

Keep in mind that this type of curvilinear response is showing up with many disease conditions, at different levels. For preterm births, for example, the plateau is at about 40 ng/ml (not 30). This type of response pattern is one of the reasons we have a range of a recommended levels from 40-60 ng/ml (100-150 nmol/L) based on the condition. I personally target the upper level in order to take care of the majority of conditions.

We do not know yet if taking vitamin D after you have been diagnosed with diabetes is a benefit, however, there are many in the community who will attest to the fact that it helps them and/or their patients.  We'd like to add some questions about this to our current study so we can start to track this as well! 

Keep up the good work, thanks again to all of you for your participation.  We now need your help to make sure this publication is OPEN SOURCE (everyone can read it). We have an open invoice for $3000 to pay for that access. Please donate today to help spread the word!  We will be happy to highlight any commercial sponsors that step up in our next newsletter.      





Carole Baggerly 

Director, GrassrootsHealth

A Public Health Promotion & Research Organization

Moving Research into Practice NOW!

Vitamin D and Type 2 Diabetes


Where is the data from?


GrassrootsHealth data is collected from at-home 25(OH)D blood tests from people of all ages, health status, and geographic location. Along with each blood test participants also complete a questionnaire which includes a series of health questions. We ask that participants complete a new test and questionnaire every 6 months for 5 years so that we can get long-term data. (Anyone who wishes to continue beyond 5 years is certainly welcome to do so.)  


For this study on diabetes, the GrassrootsHealth data was compared to data from the National Health and Nutrition Examination Survey (NHANES). NHANES is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The survey is unique in that it combines interviews and physical examinations. To match the data from the two data sets for comparison, GrassrootsHealth data was limited to participants 20 years and older residing in the United States who had not had a history of diabetes more than a year before enrollment.  


Why study diabetes?


According to the Centers for Disease Control (CDC), diabetes afflicts 29.1 million people in the United States, about 9% of the population. Type 2 diabetes accounts for 90-95% of adult diabetes cases. The CDC expects the number of cases to double or triple in the next 40 years. Diabetes is the leading cause of kidney failure, non-traumatic lower limb amputations, and new cases of blindness among adults and is the seventh leading cause of death in the United States. The estimated total yearly cost of diabetes in the United States is $245 billion.


A 60% lower incidence rate of type 2 diabetes?


Yes! Our cohort has an average 25(OH)D level of 41 ng/mg vs. NHANES with an average of 22 ng/ml. When comparing the number of cases seen in each population group in the study period, the GrassrootsHealth cohort has a full 60% lower incidence rate of diabetes. For more detail on the similarities and differences of these cohorts, check out table 1 of the paper.   





Want to know more?


The paper describes the scientific method that was used and both cohorts in detail.


Read Paper  

Interview of the Week  pic of mic


Vitamin D and Diabetes

Robert Scragg, MD, PhD

August 5, 2015


Listen to phone interview   


Robert Scragg, MD, PhD, is Professor of Epidemiology, and Head of the Section of Epidemiology & Biostatistics, at the School of Population Health, University of Auckland, New Zealand. He is a graduate of Adelaide Medical School and trained in epidemiology in the late 1970s at the CSIRO Division of Human Nutrition, Adelaide, South Australia, where in 1981 he published the hypothesis that sun light and vitamin D may protect against cardiovascular disease. Since then he has carried out studies in New Zealand showing that low vitamin D status is associated with an increased risk of both coronary heart disease and diabetes. He has also published several important papers on vitamin D status and health from the US National Health and Nutrition Examination Surveys (NHANES). He is a principal investigator on the Vitamin D Assessment (ViDA) Study, a large randomized trial to determine if vitamin D supplementation prevents cardiovascular disease and other adverse health outcomes.


Carole Baggerly, Director of GrassrootsHealth, interviews Scragg about his experience with vitamin D, health and diabetes.Scragg was one of the co-authors of our paper, and has been involved in vitamin D research for 35 years. In this interview Baggerly and Scragg discuss the cohorts used, methodology used - and the future of vitamin D and public health - will people listen? Scragg also weighs in on daily dosing. He references two on-going studies, one giving monthly doses and the other daily doses.   


Listen to phone interview 


Editor's Letter 


This is another newsworthy item, so since you are part of our grassroots effort - tweet away! Facebook! Forward this news to all your friends!


Once again, your D*action test results and questionnaire responses have helped us provide scientific data that adequate levels of vitamin D (40-60 ng/ml, but specifically over 30 ng/ml in this case) will lower the risk of type 2 diabetes.


I hope you enjoy the questions and answers from last week. These were answered directly by Dr. Hollis, they have not been edited. You will read his views on questions such as daily dosing, vitamin K, magnesium, daily supplement levels, and sun exposure.


Feel free to ask more questions this week through our "Ask a Scientist" area. This week the questions will go to Prof. Robert Scragg of the University of Auckland, New Zealand.


Spread the word!


Susan Siljander       

Marketing Director, GrassrootsHealth

A Public Health Promotion & 

Research Organization  

Moving Research into Practice NOW!
Order Your Home Vitamin D Test TODAY!
Your participation in this project funds all the GrassrootsHealth research and promotion.


What about vitamin K?

What about magnesium?

How should I dose daily?

Click here to view the questions and answers from last week's newsletter. 

Dr. Bruce Hollis
Questions answered by Dr. Bruce Hollis, PhD, Medical University of South Carolina


We now need your help to make sure this publication is OPEN SOURCE (everyone can read it).  We have an open invoice for $3000 to pay for that access.  Please donate today to help spread the word!  We will be happy to highlight any commercial sponsors in our next newsletter as well. 

pic of mic
Interview of the Week

Vitamin D and Diabetes

Robert Scragg, MD, PhD

Epidemiology & Biostatistics

The University of Auckland, New Zealand

August 5, 2015


Listen Now 


If you have a question on vitamin D and diabetes - please click here and they will be answered by Prof. Robert Scragg.    

We will publish the answers in a future newsletter.  

Open to any US woman, 18 years or older, at 12-17 weeks of pregnancy


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Incidence rate of type 2 diabetes is >50% lower in GrassrootsHealth cohort with median serum 25-hydroxyvitamin D of 41 ng/ml than in NHANES cohort with median of 22 ng/ml

Sharon L. McDonnell, MPH

Leo L. Baggerly, PhD

Christine B. French, MS

Robert P. Heaney, MD

Edward.D. Gorham, PhD

Michael F. Holick, PhD, MD

Robert Scragg, MD, PhD

Cedric F. Garland, Dr PH FACE

July, 2015

Read Paper


CDC National Diabetes Statistics Report 

July 9, 2014

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