Frequently Asked Questions

I have an autoimmune disease, what should I do to start the Coimbra Protocol?

To start, you must find a doctor trained by Dr. Cícero, a doctor who knows how to apply the treatment. The Coimbra Protocol cannot be carried out on one's own, and patients cannot take high doses of vitamin D alone. Here is the list of Spanish-speaking doctors (if you do not find a doctor in your country, the doctors on the list can assist you remotely, via telemedicine).

Does the Coimbra Protocol have side effects?

No, there are no side effects when the patient strictly follows all the recommendations of the Coimbra Protocol doctor. The treatment is safe when carried out under medical supervision.

How much does it cost to follow the Coimbra Protocol?

The doctors are independent, and each one has their own fees, so the ideal is to speak directly with them. Here is the list of Spanish-speaking doctors.

Do I need to stop taking the conventional medication to start the Coimbra Protocol?

No, it is not necessary. The decision to stop conventional drugs is exclusive to the patient. If the patient wants to quit conventional medication, this must be guided by the treating physician, that is, the Coimbra Protocol doctor (the transition must be done safely).

Is the Coimbra Protocol the cure for autoimmune diseases?

Initially, there is no talk of a 'cure,' but rather of 'suppression' of autoimmune diseases. This means that as long as the patient is undergoing the treatment, which is initially lifelong, they will not have any more flare-ups.

"I do not talk about curing autoimmune diseases, but rather about preventing these diseases from manifesting in the body while the person maintains high vitamin D levels, while also taking preventive measures that require a special diet and abundant hydration." Cícero Galli Coimbra, neurologist, PhD

If I take vitamin D supplements, can I get intoxicated from sun exposure?

The body is intelligent, and the skin interrupts vitamin D production when the body detects that there are already adequate levels in the bloodstream (due to the use of supplements).

About sun exposure:

"Unfortunately, dermatologists demonized sun exposure, when in reality it is a matter of rationalizing exposure time. You don't need a prolonged time capable of causing skin cancer; you need 20-30 minutes of sun exposure, depending on the area of the body exposed. For example, if you wear bathing suits in the pool or beach and lie in the sun, in 10 minutes you can produce 20,000 IU of vitamin D; when you reach that level, the skin stops production because the organism learned that excess vitamin D can cause damage or toxicity. The skin interrupts production."

Cícero Galli Coimbra, neurologist, PhD

Is there a simplified explanation of the Coimbra Protocol?

Autoimmune diseases appear due to a genetic error that prevents the body from properly using vitamin D. Vitamin D regulates the immune system and prevents it from attacking the body itself. Each person needs a different dose. Never copy someone else's dose.

The Coimbra Protocol is 'precision medicine.' It is an example of precision medicine: the treatment adapts to each body, meaning that what is therapeutic and works for one patient can be toxic for another. Doses are adjusted according to laboratory tests. Only a trained doctor can apply this protocol.

Those interested in more details about the Coimbra Protocol can find extended information here.

Does the Coimbra Protocol have an age limit?

No, the Coimbra Protocol can be applied from babies to elderly people (our social media networks are full of testimonials).

Why don’t medical associations accept the Coimbra Protocol?

Because current studies are pilot trials with few patients and no phase III data.

Why no large-scale trials? Because they cost millions and only happen when patents exist. Vitamin D is cheap and generic - there’s no financial incentive.

The system demands a type of evidence that will never be produced for something unpatentable. Yet published data already demonstrate efficacy and safety. This is not about conspiracy but about how evidence and business models work.

The Coimbra Protocol also cannot be evaluated through the standard randomized double-blind model, since vitamin D doses are adjusted individually based on lab parameters. Each patient has a unique biological resistance, making a uniform trial design unfeasible.

Discrediting a physician with decades of research and publications (Dr. Coimbra) is not a scientific argument, but a simplification.

The real issue lies in how research and funding models operate: what cannot be patented rarely receives large-scale investment, even when clinical results are consistent.

Several studies document the protocol.