Published on April 2, 2021

View these GrassrootsHealth Seminar presentations by our trusted scientists and doctors on all kinds of topics for your health

As part of our efforts to bring reliable, scientific information about vitamin D to the public, GrassrootsHealth has hosted several in-person seminars at the University of Carlifornia, San Diego (UCSD) with presentations by vitamin D scientists, researchers, and doctors from all over the world.

Each of these presentations are now available for anyone to view on UCTV! See the list of presentations below and make some time to watch the ones that speak to your interests or concerns.

Vitamin D for Public Health – Integrating Sunshine, Supplements and Measurement for Optimal Health 2014

Learn about the science of vitamin D and sunshine. Notable researchers discuss conditions affected by vitamin D, ways to improve patient outcomes, how to solve the deficiency epidemic and much more.

Public Health Initiative: Meeting the Vitamin D Requirements of the Pregnant Woman and Improving Health Outcomes; NICHD Vitamin D Lactation Summary Data
Carol L. Wagner, MD, Medical University of South Carolina, discusses how vitamin D status during pregnancy varies around the globe and the implications of maternal vitamin D deficiency for both the mother and her developing fetus.

Cost/Benefit of Optimal Health with Sunshine, Vitamin D
William B. Grant, PhD, Sunlight, Nutrition, and Health Research Center, looks at the costs and benefits of increasing vitamin D-related behavior. Identify the cost reductions of increased vitamin D as it compares to the cost of skin cancers.

Design Components of Interventions/Studies of Vitamin D
Robert P. Heaney, MD, Creighton University, examines the critical design features and standard frameworks for vitamin D studies.

Vitamin D Usage in Alaska
Overview of legislation and promotion of Vitamin D in Alaska by State Senator Paul Seaton.

Results of a Prostate Cancer/Vitamin D Trial: Effectiveness, Safety, Recommendations
Bruce W. Hollis, PhD, Medical University of South Carolina shares the results of a recent trial including identifying the vitamin D level needed to protect the prostate gland.

Vitamin D and Sunlight for Cancer Prevention
Cedric F. Garland, Dr PH FACE, UCSD School of Medicine, identifies cancers that have lower incidence at the equator and discusses the characteristics of the human photoprotective response.

Vitamin D, Sunshine, Optimal Health: Putting it all Together
Robert P. Heaney, MD, Creighton University explores why vitamin D is important, how it works, how we get it and how much we need.

Why the Sun is Necessary for Optimal Health
Alexander Wunsch, MD, Wismar University of Applied Sciences, Germany gives a historical perspective on sunlight exposure and explains how both the public’s and medical community’s perspective has changed over time.

Sunlight and Your Health: An EnLIGHTening Perspective
Michael F. Holick, PhD MD, Boston University Medical Center gives an energetic talk on the positive impacts of sunlight on your health. How can we balance current thinking on the negative effects of sun exposure with new research on its benefits? How does sunlight help in the production of vitamin D? Join Dr. Holick as he explains how sunlight reaches us, how it is absorbed by the skin and much more.

Vitamin D and Public Health Practice
Mary Pittaway, MA, RD identifies ways to educate communities about vitamin D from a public health perspective.

Prevention of Type 1 Diabetes with Vitamin D and Sunshine
Edward Gorham, PhD, UC San Diego School of Medicine, describes the prevalence of vitamin D deficiency in terms of sun avoidance and person, place, and time. He identifies key items of evidence suggesting a protective association between sunlight, vitamin D, and risk of type 1 diabetes. He also lists the ways in which addressing vitamin D deficiency can have a positive impact on public health.

Vitamin D Measurement, the Key to Change
Alexander Wunsch, MD, Wismar University of Applied Sciences, Germany, discusses the importance of measurement when studying vitamin D.

My Data – My Answers: Vitamin D
Overview of GrassrootsHealth, conclusions of studies on specific health issues, and its global data collection and advocacy of Vitamin D for overall health by Carole Baggerly, Director of GrassrootsHealth.

Diagnosis and Treatment of Vitamin D Deficiency Seminar 2010

GrassrootsHealth Seminar April 9, 2010 – Is vitamin D the wonder vitamin? Can it prevent certain cancers and chronic diseases? Find these answers and more in this series brought to you by UCSD School of Medicine and GrassrootsHealth where experts discuss the latest research on vitamin D.

Vitamin D: Interactions of Vitamin D and Calcium
Robert Heaney, MD, talks about vitamin D and calcium metabolism safety. Series: “Vitamin D Deficiency – Treatment and Diagnosis”

Vitamin D: Diabetes and Colon Cancer in the Japanese Population
Tetsuya Mizoue, MD, talks about vitamin D, diabetes and colon cancer in the Japanese population.

Vitamin D: Pregnancy and Lactation – Preventing Complications, Growing Healthy Babies
Carol Wagner, MD, discusses vitamin D and its role in growing healthy babies from pregnancy to lactation.

Vitamin D: UV, The Original Source – How to Use It
Edward Gorham, PhD, talks about how to use the sun, or UV light, for vitamin D synthesis.

Vitamin D: Nutrient, Not A Drug
Robert Heaney, MD, talks about vitamin D as a nutrient, not a drug.

Vitamin D: Role in Preventing Cancer, How Does it Work?
Dr. Cedric Garland discusses vitamin D and its role in preventing cancer.

Diagnosis and Treatment of Vitamin D Deficiency Seminar 2009

GrassrootsHealth Seminar December 2, 2008 – Can vitamin D help prevent certain cancers and other diseases such as type 1 diabetes, cardiovascular disease, and certain autoimmune and chronic diseases? To answer these questions and more, UCSD School of Medicine and GrassrootsHealth bring you this innovative series on vitamin D deficiency. Join nationally recognized experts as they discuss the latest research and its implications.

Vitamin D Deficiency: Analysis and Approach in a Comprehensive Cancer Center
Donald Trump, MD, discusses what has been learned about vitamin D deficiency from studying cancer patients.

D-Lightful Vitamin D: Bone & Muscle Health and Prevention of Autoimmune and Chronic Diseases
Michael Holick, MD, discusses vitamin D relating to bone and muscle health and the prevention of autoimmune and chronic diseases.

Vitamin D & Cardiovascular Disease- New Frontiers for Prevention
David Sane, MD, discusses the prevention of cardiovascular disease through vitamin D.

Vitamin D and Diabetes-Can We Prevent it?
Frank Garland, PhD, discusses vitamin D and the opportunity for prevention of diabetes.

Skin Cancer/Sunscreen – the Dilemma
Edward Gorham, PhD, discusses the dilemma of skin cancer and sunscreen use.

Dose-Response of Vitamin D and a Mechanism for Cancer Prevention
Cedric Garland, Dr. P.H., discusses the expected vitamin D serum level for cancer prevention.

What’s a Vitamin D Deficiency?
Robert Heaney, MD, gives an overview of vitamin D deficiency.

More Videos on Vitamin D

Additional videos, including webinars hosted by GrassrootsHealth, interviews with vitamin D experts, short sunlight snippets, and more can be viewed from the GrassrootsHealth videos page.

Should You be Getting More Vitamin D to Help Protect Your Health?

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 another 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.

Click to Enlarge & Print

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!