The epidemic of suicides, mental health disease, and drug overdose as well as chronic fatigue were a group of issues that I had considered individually until today. Perhaps the reason so many people are suffering in today’s environment are because of sub-optimal vitamin D3 dosing and blood levels causing altered gut microbiota and reduced serotonin production.

Here are the facts:

  • The number of people using antidepressants jumped 65% between 2002-2017, and 12.7% of people age 12 and older had used antidepressants in the past month.1
  • In the human body, 70-80% of the immune system is in the alimentary tract.2,3
  • The Alimentary tract is the tube that connects our mouth to our anus and where we process food and liquids.
  • The gut microbiota (see previous post) is located mainly in the large intestine and produces around 90% of our body’s serotonin.4
  • Serotonin is involved in many functions in the body including the state of brain arousal (stimulated or relaxed), contributing to a state of well-being and happiness, and is a precursor to melatonin which is important for sleep.5
  • Vitamin D3 modifies our immune system to become stronger.6,7
  • Selective serotonin reuptake inhibitors (SSRI’s) are the most widely prescribed antidepressants in the United States and many other countries.8
  • According to the #Mayo Clinic website, “SSRI’s ease depression by increasing serotonin levels in the brain.”9

First, I offer a couple of observations. In treating chronic pain for over 23 years, two of the main symptoms were depression and poor-quality sleep. The pain doesn’t shut off just because you want to sleep. In my residency training at University of Massachusetts I was taught to use SSRI’s as they were and continue to be the best tool I had to offer my patients for these symptoms.

So successful were SSRI’s, in fact, that at one point in my practice, I was the largest prescriber of them in the five-state region, including Texas and the surrounding states. It also had some effect on patients’ pain which I found useful to reduce opioid use.10 It caused side effects, the major being weight gain and reduced sex drive. I was always looking for a better option. Then, in 2010, I started recommending optimal doses of vitamin D3 with Omega 3, two grams twice a day*. Soon I rarely needed to prescribe the SSRI’s anymore.

One of theories on vitamin D3’s effects on the immune system is that it alters the gut biota to become healthier. It does this to promote the survival of beneficial bacteria like the ones that produce serotonin. Thus, increasing your serotonin levels helps to alleviate depression, poor quality sleep and chronic pain. Without the correct gut microbiota can result in a 90% reduction in serotonin production by the gut microbiota. I believe optimal dosing of vitamin D3 restores the ideal microbiota, so you don’t have this reduction in serotonin production. This is huge. As otherwise for your body to try to produce the missing serotonin, which it probably can’t, certainly contributes to the epidemic of depression we are seeing and is a further drain on the limited energy your body can produce. There is certainly more to this problem but this is the reason we need to do studies of vitamin D3 at optimal dosing and blood levels.

* At that dose it can thin your blood.

  1. Pratt LA, Brody DJ, Gu Q. Antidepressant Use Among Persons Aged 12 and Over: United States, 2011–2014. NCHS Data Brief No. 283 August 2017.
  2. Suzuki K, Ha SA, Tsuji M, Fagarasan S. Intestinal IgA synthesis: a primitive form of adaptive immunity that regulates microbial communities in the gut. Semin Immunol 2007;19(2):127–35.
  3. Macpherson AJ, Slack E. The functional interactions of commensal bacteria with intestinal secretory IgA. Curr Opin Gastroenterol 2007;23(6):673–8.
  4. Yano JM, Yu K, Donaldson GP, et al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell. 2015 Apr 9;161(2):264-76
  5. Frazer A, Hensler JG. Serotonin Involvement in Physiological Function and Behavior. In: Siegel GJ, Agranoff BW, Albers RW, et al., editors. Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition. Philadelphia: Lippincott-Raven; 1999. Available from:
  6. Mora JR, Iwata M, von Andrian UH. Vitamin effects on the immune system: vitamins A and D take centre stage. Nat Rev Immunol. 2008;8:685–698.5.
  7. Von Essen MR, Kongsbak M, Schjerling P, et al. Vitamin D controls T cell antigen receptor signaling and activation of human T cells. Nat Immunol. 2010 Apr; 11(4):344-9.
  8. Preskorn SH, Ross R, Stanga CY (2004). “Selective Serotonin Reuptake Inhibitors”. In Sheldon H. Preskorn, Hohn P. Feighner, Christina Y. Stanga, Ruth Ross. Antidepressants: Past, Present and Future. Berlin: Springer. pp. 241–62. ISBN 978-3-540-43054-4.
  10. Santello M, Nevian T. Dysfunction of Cortical Dendritic Integration in Neuropathic Pain Reversed by Serotoninergic Neuromodulation. 2015, Neuron 86, 233–246.

*The information posted above is for educational purposes only. Always check with your doctor before initiating any changes in your medical treatment. If you do not, then The Two-Minute Health Fact, Dr. Judson Somerville, nor The Optimal Dose is responsible!

1 Comment

Pharm · June 3, 2019 at 12:27 am

Sweet blog! I found it while surfing around on Yahoo News.

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