Published on October 15, 2025
March 6, 1963, to August 27, 2025
We extend our deepest respect and remembrance to Dr. Leslie Ray “L. Ray” Matthews, a distinguished trauma surgeon and internationally recognized vitamin D researcher… and a true vitamin D super-star.
Dr. Matthews made pioneering contributions to the medical community through his research on the role of vitamin D in the prevention and treatment of concussions, traumatic brain injuries, and other critical conditions. He implemented vitamin D testing and supplementation protocols as standard of care for all his patients – and while working in the fourth busiest level 1 trauma center in the United States – he was able to cut the rate of heart attacks, strokes, falls, pneumonia, overall mortality, readmissions and the length of hospital stay just with vitamin D.
Dr. Matthews discussed his use of vitamin D in practice and how vitamin D changed hospital patient outcomes in this GrassrootsHealth interview, titled “Vitamin D Deficiency vs Toxicity: What’s More Dangerous?”
A native of Indianola, Mississippi, Dr. Matthews served as a Professor of Surgery at Morehouse School of Medicine and a trauma surgeon at Grady Memorial Hospital in Atlanta, Georgia. He passed away on August 27, 2025. His legacy continues to inspire physicians, researchers, and advocates dedicated to advancing vitamin D science and its application in clinical practice.
His obituary page is here, where you can send flowers or a card, or plant a tree in his memory.
We honor his extraordinary career and lasting impact on medicine.
The GrassrootsHealth Team
Dr. Matthews’ Notable Achievements
A timeline of Dr. Matthews’ professional milestones was featured on Marquis Who’s Who; the following are only a handful of his notable achievements. View them all here.
2010
Speaks at the Centers for Disease Control on two occasions and the Federal Drug Administration six times on the subject of vitamin D through today.
2012
Introduces the concept of vitamin deficiency to U.S. Army generals as a national security threat.
2015
Is honored by Governor Tate Reeves and the Mississippi State Legislature for his research on vitamin D.
2018
Speaks before the United Nations; Is inducted as Fellow of the Royal Society of Medicine.
2019
Name is engraved on the Wall of Honor at the Royal Society of Medicine; Submits patent for vitamin D use on patients with brain injuries.
2021
Pioneers the use of high dose vitamin D treatment to care for a patient with a brain stem injury; Secures provisional patent for vitamin D use in COVID patients.
Measure Your Vitamin D and Other Important Nutrients
If you haven’t had your vitamin D levels checked recently, now is the time! With so many Americans still falling short, awareness is the first step toward change.
Measuring and calculating a supplementation amount to help reach and maintain a target level, or taking loading doses to correct deficiency faster, could possibly make all the difference in overall health, wellbeing, and how a current disease situation progresses. Test your level now!
Create your custom home blood spot kit by adding any of the following measurements, along with your vitamin D:
- Omega-3 Index (with or without Ratios AA:EPA and Omega-6:Omega-3)
- Magnesium (with additional Elements copper, zinc, selenium, mercury, and cadmium)
- hsCRP as a marker of inflammation and HbA1c as a marker of blood sugar health
Having and maintaining healthy vitamin D levels and other nutrient levels can help improve your health, now and for the future. Enroll and test your levels today, learn what steps to take to improve your status of vitamin D (see below) and other nutrients and blood markers, and take action! By enrolling in the GrassrootsHealth projects, you are not only contributing valuable information to everyone, 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.
How Can You Use this Information for YOUR Health?
Having and maintaining healthy vitamin D and other nutrient levels can help improve your health now and for your future. Measuring is the only way to make sure you are getting enough!
STEP 1 Order your at-home blood spot test kit to measure vitamin D and other nutrients of concern to you, such as omega-3s, magnesium, essential and toxic elements (zinc, copper, selenium, lead, cadmium, mercury); include hsCRP as a marker of inflammation or HbA1c for blood sugar health
STEP 2 Answer the online questionnaire as part of the GrassrootsHealth study
STEP 3 Using our educational materials and tools (such as our dose calculators), assess your results to determine if you are in your desired target range or if actions should be taken to get there
STEP 4 After 3-6 months of implementing your changes, re-test to see if you have achieved your target level(s)
