PREMISE: How three popular topics in alternative health risk becoming new dogmas if not examined in their true complexity.

Functional medicine grew thanks to a specific promise: to look at the whole person rather than just a single number. It's a serious promise, and one that has largely been kept. But in its popular version, a trend is taking shape that I'm well aware of, because it's the same one I've criticized mainstream medicine for years: the reduction of a complex biological system to an isolated marker, and of a personalized protocol to a standard pill.

You know the three most common cases. “You are vitamin D deficient, supplement D3 . ” “You have the MTHFR mutation, take methylfolate . ” “You have a copper/zinc imbalance, increase your zinc .” Three short sentences, three convenient diagnoses, three ready-made protocols.

Official medicine has its own reductionism—lowering cholesterol, supplementing low vitamin D, administering low iron—and has created "deficiencies" tailored to its pills. My thesis, developed over years of work on mineral metabolism and light, and which will culminate in my next book, is a symmetrical warning: treated reductively, these three topics create the very problems they claim to solve. No complex system can be fixed with a single variable. And an alternative that reproduces the method of the model it criticizes is not an alternative: it is a copy with a different label.

The target of this article, let's be clear, is not functional medicine as a whole. It's a methodological error. And methodological errors are dismantled by providing data.

VITAMIN D: WHEN THE MARKER BECOMES A DIAGNOSIS

Let's concede the fact right away: the alternative intuition is correct. Official medicine has reduced vitamin D to a number that needs to be increased, and the criticism of this trivialization is legitimate. The problem is that the most common popular response— "almost everyone is deficient, supplement with D3" —is the same trivialization in reverse.

My thesis, consolidated over years of publications on this blog and especially in my third book, " VITAMIN D" : cholecalciferol is not a vitamin, it is a secosteroid hormone. The 25(OH)D test measures the inactive, storage form—not the active form. A low level is often a marker of inflammation, not the cause of health: the body is shifting its metabolism, not "losing" a molecule. And vitamin A and vitamin D act as a double-key system on nuclear receptors: D3 without retinol can be ineffective or toxic. I present this model as a framework—the biochemistry of receptors that share the same partner has been consolidated for decades; its practical translation into the clinical setting is my thesis.

The data on industrial production is documented: sheep lanolin, solvent refining, cholesterol extraction, chemical conversion to 7-dehydrocholesterol, artificial UV irradiation. The same molecule is registered as an active ingredient in rodenticides (Merck Veterinary Manual). And independent tests on commercial products are not reassuring: phthalates in 100% of samples and pesticides in almost two-thirds (I wrote about it here: https://www.evolutamente.it/integratori-vitamina-d-contaminanti-test-epa-2026/ ).

Large trials have failed everywhere: VITAL on cancer and cardiovascular disease (NEJM 2019), VITdAL-ICU in intensive care (JAMA 2014), the single 540.000 IU bolus in intensive care with a 90-day mortality rate of 23,5% in the treatment group versus 20,6% in the placebo group—a difference not statistically significant, but in the wrong direction (NEJM 2019). In 2024, the Endocrine Society discouraged routine testing and supplementation in healthy adults under 75. And in 2026, an observational study in BMJ Open associated routine supplementation with more rapid cognitive decline, only in those who started with normal levels—an observational study, a mild effect, not causal: calling it that is a matter of method, and it doesn't change the direction of the signal.

I've been making this point for years: the sun is not a vitamin D factory. It produces an entire family of photoproducts—lumisterol, tachysterol, previtamin D3, and CYP11A1 metabolites—that the capsule doesn't replicate. And light also affects other things: nitric oxide, circadian biology, and mitochondria (here: https://www.evolutamente.it/meccanismi-fotobiomodulazione-gradi-inferenza/ and here: https://www.evolutamente.it/fotoni-infrarossi-metabolismo-mitocondriale/ ).

Anyone who truly wants to assess their condition shouldn't stop at a single number: before making any decisions, the complete picture—25(OH)D, but also 1,25(OH)₂D, PTH, and ionized calcium—should be reviewed by a professional. And even before the blood count, there's the starting question: how much light does this person get? This isn't just decorative caution: it's the difference between evaluating a system and raising a marker.

For more information on cholecalciferol: https://www.evolutamente.it/la-vitamina-de-veleno-per-topi-approfondimento-sul-colecalciferolo/ and https://www.evolutamente.it/la-vitamina-d-colecalciferolo-e-un-farmaco-e-non-un-integratore/

MTHFR: THE GENE IS NOT A DESTINY

Let's grant the fact here too, and in full: the 677C→T polymorphism of methylenetetrahydrofolate reductase exists, has been described for thirty years (Frosst et al., Nature Genetics 1995), and produces a thermolabile enzyme. Nutritional genetics is looking at something real.

The simplification begins with the clinical translation: "you have the allele → you're sick → take the methylated pill ." The polymorphism is widespread in a significant portion of the population—a huge portion of healthy people carry it without knowing it and without consequences. It's an incomplete narrative that seems tailor-made to sell the usual magic supplement: the genotype is not destiny. Medicalizing a widespread polymorphism means turning a variant into a disease—which is exactly what functional medicine accuses mainstream medicine of when it labels cholesterol.

If a marker is needed, a functional marker exists and can be measured: homocysteine. It makes more sense to measure what the system does rather than which variant it carries. And here, biochemistry lends support to complexity: methylation is a network, not a cog. MTHFR is a flavoprotein that uses FAD, derived from riboflavin (B2)—it's no coincidence that riboflavin status modifies the polymorphism's effect on homocysteine ​​levels (García-Minguillán et al., Genes & Nutrition 2014). Then there's B12, folate, choline, betaine, alternative and redundant pathways. The "methylated pill for all mutations" reproduces the single-variable error: it fixes the most publicized cog and ignores the network that contains it.

One point must be clearly stated, because this is where the most hasty make themselves vulnerable: you CANNOT write that the MTHFR enzyme is copper-dependent, because it isn't. Its biochemistry is that of FAD. Those who work on the copper/ceruloplasmin model—and I have been working on it for months—propose, if anything, a systemic framework hypothesis: that methylation systems also reflect the body's overall mineral status. This is a working hypothesis, not consolidated literature, and it must be presented as such. Stating it openly doesn't weaken the argument; it makes it unassailable.

COPPER: THE RIGHT QUESTION IS NOT "HOW MUCH" BUT "WHERE"

The third case, the most fraught with consequences. Let's grant the fact: copper and zinc are indeed interdependent, and those who increase zinc levels are right to suspect interactions. The problem is demand.

The dominant narrative thinks in binary doses: either you're copper deficient or you're copper-toxic. But the issue isn't "how much copper"—it's its bioavailability. The regulator is ceruloplasmin, the protein that transports and activates almost all circulating copper and manages iron as ferroxidase (Hellman & Gitlin, Annual Review of Nutrition 2002). Serum copper alone tells you little: ceruloplasmin is an acute-phase protein, rising with inflammation precisely at times when functional copper levels may be low. Those who read just one number are misdiagnosing in both directions.

Zinc given alone in high doses can induce a functional copper deficiency: the effect has been documented for decades (Fischer et al., American Journal of Clinical Nutrition 1984). It's a classic case of "raising just one of the two without context" doesn't correct the imbalance: it shifts it. The body isn't a two-pan scale.

And here comes the heart of my thesis, the one for my next book: the copper/iron/ceruloplasmin triangle is the cornerstone of cellular energy metabolism. Ceruloplasmin-regulated iron reaches where it's needed; dysregulated iron—such as that administered in sulfate form for "deficiency"—is deposited in tissues and fuels the Fenton reaction, primarily mitochondrial oxidative stress. The role of retinol in ceruloplasmin synthesis and iron regulation is part of the same framework: some pieces are measured data, others are hypotheses under testing—and in the book I will distinguish as clearly as I do here.

The organ that holds the picture together is the liver: it synthesizes ceruloplasmin, it sorts iron, it detoxifies. A mineral model that ignores liver function is a map without a territory.

A clinical honesty that closes the gap: copper toxicity is real—Wilson's disease and other serious conditions. These are diagnoses that require immediate medical attention. This article isn't about those; it's about the mineral metabolism of the average person, which is a different matter.

THE RED THREAD: NO SYSTEM CAN BE FIXED WITH A VARIABLE

Let's reread the three cases together. In all three: an isolated marker treated as the primary cause, and a standardized protocol applied to non-standard individuals. Vitamin D reduced to the test value, methylation reduced to the gene, copper reduced to the ratio of zinc.

Biological systems are interconnected by design: nuclear receptors that communicate with each other, a methylation network that depends on vitamin cofactors and mineral status, minerals that regulate each other through specific transporters, light that modulates hormones and mitochondria, and the liver that sorts everything. Touching one without seeing the others doesn't fix the system: it just shifts the problem downstream, where it can no longer be measured.

The risk is historic and well-known: where conventional medicine has created "deficiencies" to be treated—cholesterol, low vitamin D, low iron—functional medicine risks creating new ones: methylfolate for everyone, zinc for everyone. The pill changes, but the method doesn't.

WHAT TO DO INSTEAD: THE CONTEXT BEFORE EVERY DECISION

There is no universal protocol, in any direction — and no dosage: that is professional work, not an article.

• Vitamin D: First the sun. Then, if an evaluation is really needed, the complete picture—25(OH)D along with 1,25(OH)₂D, PTH, ionized calcium—read by a professional, not a single number to chase.
• MTHFR: measure function, not just genotype: homocysteine, B2, B12, and folate status, and the mineral and liver context that supports the methylation network.
• Copper: ceruloplasmin and serum copper together, never separately; the relationship with zinc and vitamin A; liver function as a general picture.

Sunshine, real food, liver function, individual context. The rest is systems biology—which you read, not guess.

CONCLUSION: COMPLEXITY IS NOT AN ENEMY

Complexity isn't a barrier to dissemination: it's the reality of biology. Anyone selling you a one-variable system—a marker to raise, a gene to compensate, a mineral to dose—is selling you a map drawn on the back of an envelope.

The call for humility applies to both sides. Medicine that measures a marker and prescribes a pill, and alternative medicine that measures a gene and prescribes another, commit the same methodological error. The day they both recognize this, the conversation about health will finally be able to change direction. It's the thread I've been following for years—on mineral metabolism, light, vitamin D—and it's summarized in my next book.

WHERE WE ARE SIMPLIFYING

To be consistent with everything I've written so far, I'll also declare my simplifications. We speak of "vitamin D" as a molecule when the active metabolite is a system of receptors, transporters, and metabolites. We reduce "methylation"—a universe of epigenetic reactions on DNA, histones, and neurotransmitters—to a mere mechanism for expository purposes. We write "bioavailable copper" as a single concept when the biochemistry of ceruloplasmin is much more complex. This article itself simplifies, and for this reason I ask you to read it as a map, not as a territory. Whoever sells you the territory as a variable is also lying about the scale.

This article is the result of a collaboration between Angelo Rossiello and an advanced artificial intelligence. The primary sources were verified on PubMed. Angelo provided precise guidance on structure, tone, and objectives, and reviewed and validated each scientific statement using a method he calls a "refinement loop."

Disclaimer

This article presents the author's theses and framework hypotheses, distinct from the measured data cited in the sources. It does not constitute medical advice. Any decisions about supplements or tests should be made with a competent healthcare professional.

Sources (primary literature cited in the text, PMID/DOI verified on PubMed):

1. Hua R, Lam CS, Mok VCT, Cheung YT. BMJ Open. 2026;16(1):e106050. PMID 41571412. DOI 10.1136/bmjopen-2025-106050.
2. Manson JE, Cook NR, Lee IM, et al. VITAL. N Engl J Med. 2019;380(1):33-44. PMID 30415629. DOI 10.1056/NEJMoa1809944.
3. Amrein K, et al. VITdAL-ICU. JAMA. 2014;312(15):1520-1530. PMID 25268295. DOI 10.1001/jama.2014.13204.
4. Ginde AA, et al. VIOLET. N Engl J Med. 2019;381(26):2529-2540. PMID 31826336. DOI 10.1056/NEJMoa1911124.
5. Demay MB, et al. Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2024;109(8):1907-1947. PMID 38828931. DOI 10.1210/clinem/dgae290.
6. Frosst P, et al. Nat Genet. 1995;10(1):111-113. PMID 7647779. DOI 10.1038/ng0595-111.
7. García-Minguillán CJ, et al. Genes Nutr. 2014;9(6):435. PMID 25322900. DOI 10.1007/s12263-014-0435-1.
8. Fischer PW, Giroux A, L'Abbé MR. Am J Clin Nutr. 1984;40(4):743-746. PMID 6486080. DOI 10.1093/ajcn/40.4.743.
9. Hellman NE, Gitlin JD. Annu Rev Nutr. 2002;22:439-458. PMID 12055353. DOI 10.1146/annurev.nutr.22.012502.114457.
10. Merck Veterinary Manual. Cholecalciferol Poisoning in Animals (veterinary reference manual, cited as document).

FACT CHECK — “THE THREE GREAT SIMPLIFICATIONS” (12/09/2026)

TO BE CORRECTED (only 1 point, but it's yours)

"Simplification begins with clinical translation..." — MTHFR section, second paragraph. You've corrected the title and slug to "simplifications," but the last instance of "simplification" remains alive in the body. Since you just banned it, it's on the prowl too:

“ Simplification begins with the clinical translation: “you have the allele → you are sick → take the methylated pill”.”

This is the only remaining occurrence — I've checked the entire text word for word.

MICRO-TYPES (optional, 30 seconds)

1. “in my third book VITAMIN D: cholecalciferol” —there is a space before the colon. → “VITAMIN D: cholecalciferol.”
2. “It's an incomplete narrative” — with the right accent, it's "It's an incomplete narrative." In WordPress, a straight apostrophe works, but using the accented one makes it cleaner.

EVERYTHING ELSE VERIFIED ✓