Cícero Coimbra MD, PhD is a neurologist and professor at the Federal University of São Paulo, Brazil. Over the past two decades, he has created a clinical protocol to treat autoimmune diseases with the establishment of adequate systemic levels of vitamin D, including in individuals with a genetic predisposition to insufficiency. This therapeutic approach relies on doses of vitamin D that range from 35,000 IU1 to 300,000 IU 2 per day (87.5 to 750 times the recommended daily amount); therefore, this is a medical treatment that must always be carried out under the supervision of a qualified doctor. 

     Dr. Coimbra based his protocol on medical literature describing positive effects of vitamin D on the immune system4, particularly with regard to its important immunoregulatory role5,6. Because MS is the most common neurological autoimmune disease, he started prescribing vitamin D to MS patients. That was the beginning of what is presently known as the Coimbra Protocol.

      With doses around 10,000 IU/day, Dr. Coimbra saw a remarkable clinical improvement in the vast majority of his patients. From that point on, the doses were further increased, always supported by laboratory tests to ensure patients would not experience side effects. The results were that many of these patients found themselves completely free of the symptoms and manifestations of the disease. During the next ten years, Dr. Coimbra and his staff gradually modified and perfected the treatment, mostly in terms of the prescribed daily doses, which grew steadily higher. From 2012 on, the desired level of efficacy was achieved, and the Coimbra Protocol became very similar to what it is today.

     Although the protocol includes other supplements besides vitamin D, achieving the correct level of vitamin D for each patient accounts for 95% of the treatment success. Therefore, in the beginning of treatment, parathyroid hormone or parathormone (PTH) levels are measured, and then measured regularly during the treatment. PTH is a hormone released by the parathyroid glands. Vitamin D suppresses the PTH; consequently, as vitamin D levels go up, PTH levels go down. When PTH levels are kept at the lowest normal limit, the best biological effect of vitamin D is reached for that individual.

     In the protocol, vitamin D daily doses are increased until the desired PTH level is achieved. When this happens, any resistance to vitamin D is overcome and the patient starts benefiting from its immunodulatory effects. It usually takes two years to adjust the doses of vitamin D, after which the treatment consists of maintenance of the proper levels of PTH and calcium.

Some of the tests required by the protocol include, but are not limited to the following (all are in the blood unless otherwise specified):

• PTH

• 24-hour calciuria (calcium excretion in urine)

• Vitamin B12

• 25(OH)D3 (the form of vitamin D tested)

• Total and ionized calcium

• Urea and creatinine (kidney function tests) 

• Albumin (a protein that also indicates liver function)

• Ferritin (the form of iron stored by the liver)

• Serum phosphate (a marker of bone health)

• 24-hour phosphaturia (phosphorus excretion in the urine)

• TSH and FT4 (thyroid function tests)

• Bone densitometry (dual-energy x-ray absorptiometry or DXA to assess bone integrity)

Side Effects

The possible side effects of taking high doses of vitamin D for extended periods of time are an excess of calcium in the blood (hypercalcemia) or in the urine (hypercalciuria, with potential for impaired kidney function), and loss of bone mass. Excess calcium can be prevented with a low-calcium diet, safety can be enhanced with copious fluid intake (2.5 liters/quarts per day), and regular lab tests can help ensure calcium levels are kept under control3

Foods to Forgo

Calcium-rich foods and beverages, including those that have been fortified with calcium. The following is a list of commonly consumed items that meet that description:

• Milk, cheese, yogurt, pudding, and other dairy foods (except for butter and sour cream)

• Vegan “milk”s and their products fortified with calcium

• Other calcium-fortified foods and beverages, such as orange juice, breakfast cereals, and baked goods made with calcium-fortified flour – check the label!

• Oranges

• Dried figs

• Dark green leafy vegetables such as arugula, broccoli and broccoli rabe, Brussels sprouts, greens for cooking (beet, collard, mustard, turnip), kale, and okra (note: spinach contains a high amount of calcium, but the body cannot absorb it well)

• Butternut squash

• Sweet potato

• White beans

• Almond butter

• Sesame butter (tahini)

• Chia seeds

• Edamame (young green soybeans)

• Firm tofu made with calcium – check the label!

• Fish where the bones are consumed, such as sardines and pilchards

• Many pre-made and powdered shakes – check the label!

• Many multivitamin-mineral supplements – check the label!

• Tube-feeding formulae

Foods for Moderation

Nuts (seeds are not mentioned, but those other than sesame are likely in the same category)

What to Favor

Water, at least 10-11 glasses (8 fluid ounces or 240 ml) per day – more on days in which you sweat a lot or are running a fever. This is to ensure that the kidneys will be able to eliminate excess calcium without difficulty.

Every individual is different, so test results will ultimately determine if the diet is being correctly followed or if more restrictions are needed. 

     To avoid loss of bone mass, patients on the protocol are instructed to practice a daily routine of aerobic exercise that places vertical pressure on bones, such as a daily 30-minute brisk walk. Those who cannot engage in such exercise may ultimately require medication against osteoporosis, such as bisphosphonates.

Additional Supplements

• Vitamin B2 (Riboflavin)

• Vitamin B12 (Cobalamin)

• Choline

• Chromium Picolinate

• Magnesium (Glycinate, Malate, Citrate, Chloride, etc.)

• Selenium

• Coenzyme Q10 (CoQ10)

• Omega 3 Fatty Acids

References

1.Finamor DC, Sinigaglia-Coimbra R, Neves LC, et al. A pilot study assessing the effect of prolonged administration of high daily doses of vitamin D on the clinical course of vitiligo and psoriasis. Dermatoendocrinol. Jan 1 2013;5(1):222-34. doi:10.4161/derm.24808

2.Coimbra C. Coimbra Protocol. https://www.coimbraprotocol.com/the-protocol-1

3.Amon U, Yaguboglu R, Ennis M, Holick MF, Amon J. Safety Data in Patients with Autoimmune Diseases during Treatment with High Doses of Vitamin D3 According to the “Coimbra Protocol”. Nutrients. Apr 10 2022;14(8)doi:10.3390/nu14081575

4.Charoenngam N, Holick MF. Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients. Jul 15 2020;12(7)doi:10.3390/nu12072097

5.Johnson CR, Thacher TD. Vitamin D: immune function, inflammation, infections and auto-immunity. Paediatr Int Child Health. Nov 2023;43(4):29-39. doi:10.1080/20469047.2023.2171759

6.Prietl B, Treiber G, Pieber TR, Amrein K. Vitamin D and immune function. Nutrients. Jul 5 2013;5(7):2502-21. doi:10.3390/nu5072502