The Important Role of Vitamin D – Beyond Immune and Bone Support


Kurt Woeller, DO, FMAPS


Vitamin D is an essential nutrient well known for its role in immune function, bone metabolism, and reduction in cardiovascular diseases. However, there are other less-known effects of vitamin D that this lecture will explore, including its influence on cellular metabolism linked to mitochondrial activity and neurochemical regulation within the nervous system.

Q: What to do if serum vitamin d level is really high, in 400’s for example?

A: You need to check their sources of Vitamin D and look to cut back. Just because the levels come back high like this does not automatically mean the individual is toxic, but the longer times goes on it could become a problem.This is where repeat testing is important.

Q: Please discuss systemic dangers for levels above 80-100ng/ml

A: I did discuss this in the lecture. Hypercalcemia, bone problems, e.g., pain, kidney problems, including kidney stones. 

Q: Why did the child with total D of 153 have all in the D3 category if you stated that they were supplementing that made it elevated, if D3 is from sun exposure? 

A: Diet/supplements can go to Cholecalciferol (D3) too. Here is a diagram:

Q: What do you think of Vitamin D injections? 

A: I have not used them.

Q: I have a client with high serotonin on neurotransmitter test, so this can be caused by gut inflammation, and can be corrected by vitamin D, is this right? 

A: It is more likely that the high serotonin is from something else such as supplements like tryptophan, 5-HTP, or even medications such as SSRI’s. There are certain foods that can generate serotonin too such as eggplant and bananas.

Q: What if you have the VDR SNP? How to manage? 

A: You need to test an individual’s Vitamin D levels, along with varying dosages of Vitamin D to maintain their level is the optimal range. In a situation like this running a test every 6 to 8 weeks for a period time can be done to get the levels consistent in the healthy range.

Q: Do you test animals? Dogs and cats? 

A: No.

Q: Not sure if addressed; which level should be checked? 25 (OH)d or 1,25 (OH) 2d? 

A: 25(OH)D since it has a longer half-life than 1,25(OH)D. The 25(OH)D is a good indicator of overall Vitamin D status. 

The material contained within this article and webinar is not intended to replace the services and/or medical advice of a licensed healthcare practitioner, nor is it meant to encourage diagnosis and treatment of disease. It is for educational purposes only. Any application of suggestions set forth in the portions of this article is at the reader’s discretion and sole risk. Implementation or experimentation with any supplements, herbs, dietary changes, medications, and/or lifestyle changes, etc., is done so at your sole risk and responsibility.

Kurt Woeller DO

About the Author

Kurt Woeller, DO, FMAPS

Kurt N. Woeller, DO, FMAPS, is a Doctor of Osteopathic Medicine, integrative and functional medicine physician, and biomedical Autism Treatment Specialist in clinical practice for over 25 years.

Dr. Woeller is the education director and main course developer for his Integrative Medicine Academy (https://integrativemedicineacademy.com), an online academy for health professionals. He is also the Organic Acids Test (OAT) seminar creator and presenter for Mosaic Diagnostics Laboratory (formally Great Plains Laboratory’s GPL Academy) Mosaic EDGE seminars and has been involved in monthly educational webinars for GPL/Mosaic Diagnostics, and other organizations for over a decade.

His private practice, Sunrise Functional Medicine (https://mysunrisecenter.com), focuses on specialized diagnostic testing and treatments for individuals with complex medical conditions like autism, autoimmune, gastrointestinal, certain neurological disorders, and other chronic health conditions. Dr. Woeller is a Fellow of the Medical Academy of Pediatric Special Needs (MAPS).

He has served as a clinical consultant for various laboratory companies, i.e., Great Plains Laboratory, BioHealth Laboratory, providing health practitioner education regarding functional and integrative medicine.

You can follow Dr. Woeller for ongoing education articles and videos through his Substack at https://drwoeller.substack.com/ and his YouTube channel for Integrative Medicine Academyhttps://www.youtube.com/@integrativemedicineacademy. Finally, listen to Dr. Woeller’s latest health professional interviews through his Functional Medicine Doc Talk Podcast – https://functionalmedicinedoctalk.com.