High Dose Vit D for Autoimmune Diseases

Caution: This article is for scientific exchange only. Clinical application should be under a qualified physician’s supervision. Hypercalcemia may be a major concern raised against this protocol. However, as discussed in more detail below, the vitamin D resistance appears to confer an intrinsic protection against hypercalcemia. In addition, the therapy requires the patient to take some precautionary measures. Besides the avoidance of milk products and a minimum fluid intake of 2.5 l/day, patients will need to consistently monitor multiple blood parameters and undergo regular sonographic checks of their kidneys. Practically, this requires close and regular contact with a certified Coimbra practitioner.

In preparing for an international conference on Vit D and Integrative Orthomolecular Medicine, chaired by Prof. Dr. Jorg Spitz (of Germany), of which I am honored to assist him in organizing and also providing a keynote lecture, he shared with me their recent publication: Vitamin D Resistance as a Possible Cause of Autoimmune Diseases: A Hypothesis Confirmed by a Therapeutic High-Dose Vitamin D Protocol (Lemke et al 2021 PMID: 33897704). 

This international conference is scheduled for Nov. 2021, available to the public online with a very low cost. I’ll provide updates in the future on this conference. Multi-language simulcast translation to include German, Chinese (and possibly Spanish, French, and Japanese) are being considered. Stay tuned.

I summarize here the key points of their paper on high dose Vit D on autoimmune diseases.


  • Vitamin D3 is metabolized in various tissues to the biologically most active vitamin D hormone 1,25(OH)2D3 (calcitriol). Vit D3 is metabolized in the liver to vitamin D hormone, 1,25(OH)2D3, which has multiple effects, particularly within the immune system. 
  • Acquired and hereditary vitamin D resistance exists, including blockade of vitamin D receptors. This paper focuses on acquired Vit D resistance.
  • Elevated PTH is a hallmark of Vit D resistance. One key role of 1,25(OH)2D3 is to enhance intestinal calcium absorption. If ionized calcium concentrations in blood are low, the parathyroid glands release PTH which stimulates calcium release from bones. Furthermore, PTH increases the conversion of 25(OH)D3 into 1,25(OH)2D3 in the kidneys with subsequent release into circulation. PTH also inhibits the tubular reabsorption of phosphate which in turn lowers the amount of water-insoluble calcium-phosphate salts and thus increases ionized calcium concentrations. In this way, PTH constitutes a direct feedback mechanism within the vitamin D system. A physiological 25(OH)D3 level should thereby be able to suppress PTH into the lower third of the reference range. In other words: If 25(OH)D3 levels are high, PTH should be low and vice versa. In patients with autoimmune diseases this negative feedback loop is disturbed. Based on these observations, Prof. Coimbra proposed the hypothesis of vitamin D resistance.
  • Coimbra protocol: daily doses up to 1,000 IU/kg body weight daily of vitamin D3. (This can go even as high as 300,000 IU daily for 3 months, if PTH is not low enough, Dr. Spitz told me and also per Coimbra Protocol). For approximately 15 years, patients with autoimmune diseases, particularly MS (multiple sclerosis), have been successfully treated using Coimbra’s high-dose vitamin D protocol.
  • Doses for various autoimmune diseases are listed in Table 1.   
  • Using parathyroid hormone (PTH) serum levels as an indicator for the right dose. PTH target: lower third of the normal range.
  • Not only in autoimmune diseases, high dose Vit D therapy is also suggested in cancer management due possible Vit D resistance in various cancers.
  • The German Coimbra Protocol network physicians have been collecting Effectiveness and safety data and will be published in the future. 
  • Many patients with various diseases seem to have significantly improved with this protocol (https://www.coimbraprotocol.com/testimonials-1).
  • The authors summarized: we have reviewed evidence for the hypothesis of an acquired form of vitamin D resistance, developing on the basis of a genetic susceptibility from certain SNPs within the vitamin D system and its interplay with chronic stress and/or pathogen infections that are able to partially block the VDR. Other factors that have been associated with autoimmune diseases such as low sun exposure, aging or environmental toxins could easily be integrated into this hypothesis since they would further exacerbate developing vitamin D resistance arising from the described mechanisms (Figure 2 of original paper). The hypothesis of acquired vitamin D resistance thus provides a plausible pathomechanism for the development of autoimmune diseases. We consider its therapeutic exploitation by high-dose vitamin D administration as a promising approach. Our key messages reflecting the knowledge about vitamin D resistance and its treatment are summarized in Table 2.
  • Table 1. Doses of Vit D Used in Various Autoimmune Diseases:

Vitamin D3 (cholecalciferol) is a secosteroid and prohormone which is metabolized in various tissues to the biologically most active vitamin D hormone 1,25(OH)2D3 (calcitriol)


Table 2. Key points discussed in their paper.

Vitamin D3 (cholecalciferol) is a secosteroid and prohormone which is metabolized in various tissues to the biologically most active vitamin D hormone 1,25(OH)2D3 (calcitriol)

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