✶ Written by an AI · fact-checked before publication
Every claim in The Vitamin D Myth, checked
This is the book's verification ledger, published in full. Every factual claim was extracted from the manuscript and handed to an independent blind checker — one claim, its cited source, nothing else. High-stakes claims (doses, safety, real diseases, trial numbers) were checked by three checkers who had to agree. Every checker first had to confirm the cited source actually exists.
64claims checked
62verified first pass
2flagged & corrected
The honest part: 2 claims did not survive first contact with their own sources — the checkers flagged them as misstated or unsupported. Each one was corrected in the text and re-verified by a fresh blind panel before the book was published. The table below shows the first-pass verdicts, because that's the honest number: what the machine got wrong before checking, not after.
| id | claim as written | stakes | first-pass verdict |
|---|---|---|---|
| C1 | The popular vitamin D story: nearly everyone is deficient and topping up is close to a cure-all — better immunity, lower cancer risk, healthier heart, lifted mood, more years of life. | low | verified |
| C2 | Older vitamin D books were "mostly written before the big trials reported, so the trials that actually settled these questions simply went unaddressed. | low | verified |
| C3 | Reverse causation: being ill can lower vitamin D (via inflammation, staying indoors, a body under stress) rather than low D causing the illness; measuring a marker in sick people tells you they're sick, not that a healthy reader should take a pill. | high | verified |
| C4 | Giving vitamin D to a genuinely, measurably deficient person (a child with rickets, an adult with soft aching bones) can help them; that deficiency-correction benefit does not generalise to everyone supplementing. | high | verified |
| C5 | A lab "insufficient" cutoff is a threshold someone chose — and a threshold that "crept upward over the years, reclassifying ordinary people as patients" — not itself a disease to chase upward. | high | verified |
| C6 | The marketed package under test: respiratory infections/immunity, cancer, heart/blood vessels, mood/depression, live longer, falls & fractures in ordinary adults — plus two framing claims: "almost everyone is deficient" and "test everyone / chase an optimal level. | low | verified |
| C7 | A randomised hard-outcome trial (actual fracture / cancer / death) outranks any number of observational associations; when a trial disagrees with a pile of associations, the trial wins. | high | verified |
| C8 | Across the largest, fairest trials most marketed claims came back with no meaningful benefit for a healthy already-topped-up person; the short list that held up is correcting a genuine deficiency and vitamin D's role in specific bone contexts for at-risk people. | high | verified |
| C9 | The three anchor trials are VITAL, D-Health, and VIDA. | low | verified |
| N1 | The storage form 25-OH-D is what the blood test measures — "not the active hormone, and not how much good it's doing you. | high | verified |
| N2 | When this system fails badly, children develop rickets and adults develop osteomalacia — real, serious, treatable bone diseases. | high | verified |
| N3 | Treating a lab 'insufficiency' cutoff as a disease" — a 25-OH-D result under a threshold gets stamped "insufficient" and a healthy person becomes a patient; the cutoff is a line drawn for population screening, not by itself a disease. (Myth #5 in the harm-ranked list.) | high | verified |
| C10 | Vitamin D breaks the vitamin definition: the skin manufactures it from sunlight — UVB light converts a cholesterol-like molecule in skin cells into vitamin D; topped up by a little from food and, if taken, supplements. Behaves more like a hormone. | high | verified |
| C11 | Two supplement forms: D2 = ergocalciferol; D3 = cholecalciferol. D3 is the form the skin makes and the most commonly sold. | high | verified |
| C12 | Two-step activation: liver converts it to storage form 25-hydroxyvitamin D (25-OH-D); kidney converts that to the active hormone 1,25-dihydroxyvitamin D (calcitriol). | high | verified |
| C13 | The active hormone's well-established, non-controversial job: helps the gut absorb calcium and phosphate and keeps bone mineralisation working. | high | verified |
| C14 | Vitamin D receptors were found "in tissues all over the body" — not just bone and gut; immune cells and many other tissues have them. | high | verified |
| C15 | A receptor being present is a reason to ask a question, not an answer to it" — mechanism is a hypothesis generator, not proof of clinical outcome. | low | verified |
| C16 | For immunity/respiratory infections, the trial evidence (VITAL respiratory findings, VIDA monthly high-dose results, meta-analyses pooling dozens of studies) is "modest and inconsistent at best, not the protective shield that was marketed"; the signal shrinks as you strip out deficient-at-baseline people. | high | verified |
| C17 | VITAL "found no reduction in cancer incidence in adults not selected for deficiency"; people taking 2,000 IU/day for five years did not get less cancer than placebo. | high | verified |
| C18 | Some analyses of VITAL and its extended follow-up "hinted at a possible signal on cancer *deaths*, particularly with longer time and in leaner participants" — stated as a lead, not a proven benefit. | high | verified |
| C19 | VITAL "found no reduction in major cardiovascular events" — no fewer heart attacks, no fewer strokes in the vitamin D group. | high | verified |
| C20 | A large depression-focused arm within VITAL: "the large trial data show no meaningful benefit for preventing or treating depression in the general population. | high | verified |
| C21 | The big trials, including D-Health, "show no clear all-cause mortality benefit in unselected adults"; VITAL's mortality data point the same way. | high | verified |
| C22 | The VITAL fracture ancillary "found no reduction in fractures in generally healthy, replete adults. | high | verified |
| C23 | The 25-hydroxy-vitamin-D "insufficiency"/"optimal" cutoff "crept upward" over time, each nudge reclassifying a slice of well people as "insufficient. | high | verified |
| C24 | In 2024 the Endocrine Society, whose earlier guidance had helped push those thresholds up, retreated from routine testing and supplementation in healthy adults. | high | verified |
| C25 | Mayo Clinic Proceedings reframed the entire question with a title… 'To D or Not to D?' | low | verified |
| C26 | Financial incentives sit with supplement makers, high-volume pathology running the tests, and a "deficiency pandemic" narrative requiring everyone tested then topped up; needs no conspiracy. | low | verified |
| C27 | In Australia, the TGA has acted against vitamin D products for unsubstantiated bone claims. | high | verified |
| C28 | In one large cohort, the proportion of people getting tested "rose from 42% to 93%" while the deficiency label was very likely overestimated by cutoffs set too high. | high | misstated → corrected |
| C29 | Take enough vitamin D for long enough and you get hypervitaminosis D — genuine vitamin D poisoning." Almost always self-inflicted via very high-dose products, often bought online. | high | verified |
| C30 | The mechanism is calcium: flooding the system with D floods it with calcium — hypercalcaemia — showing as nausea, vomiting, unquenchable thirst, constant urination, and, as it worsens, confusion. | high | verified |
| C31 | Pushed further, calcium damages the kidneys directly: kidney stones, calcium deposits in kidney tissue, and acute kidney injury. | high | verified |
| C32 | Published case reports and hospital admissions from vitamin D toxicity exist — real people, real megadoses, real damage. | high | verified |
| C33 | Vitamin D is fat-soluble: it doesn't flush, it accumulates over weeks and months; the "you just pee out the excess" idea is false for this vitamin. | high | verified |
| C34 | In large randomised trials of already-replete, generally healthy adults, adding vitamin D didn't buy less cancer, less heart disease, better mood, or a longer life; chasing a high level walks you toward toxicity — "all of the accumulation risk and none of the promised reward. | high | verified |
| C35 | Pinning fatigue, aches, low mood, or bone pain on "low vitamin D" and self-treating can let something serious hide — thyroid disease, anaemia, an inflammatory illness, sometimes something malignant — delaying the diagnosis that mattered. | high | verified |
| C36 | In children, severe deficiency causes rickets — bones that don't mineralise, ending soft and deformed; real, serious, treatable. | high | verified |
| C37 | In adults, the same failure of bone mineralisation is osteomalacia — soft, aching, weakened bones; real and treatable. | high | verified |
| C38 | At-risk groups who genuinely warrant assessment: limited sun exposure or covered/veiled skin; darker skin (makes less D for the same sunlight); housebound or frail elderly; malabsorption (coeliac, Crohn's, or post-bariatric surgery); exclusively breastfed infants (per local guidance); people already in structured osteoporosis care. | high | verified |
| C39 | Persistent fatigue, bone pain, muscle weakness, or a fracture are reasons to get assessed, not to self-diagnose deficiency and reach for a high-dose bottle. | high | verified |
| C40 | Thiazide diuretics (common blood-pressure tablets) reduce how much calcium you excrete; adding vitamin D raises the risk of hypercalcaemia. | high | verified |
| C41 | Sarcoidosis and other granulomatous diseases: the body activates vitamin D outside its normal control, so ordinary — even modest — doses can drive calcium up dangerously; vitamin D can be genuinely hazardous. | high | verified |
| C42 | Primary hyperparathyroidism: when the parathyroid glands are already overdriving calcium, adding vitamin D can push calcium into the danger zone; needs medical supervision. | high | verified |
| C43 | Dosing for a genuine deficiency is a decision made with a doctor, calibrated to need — not a figure copied off a forum. | low | verified |
| C44 | Correcting a genuine deficiency in a truly-short person prevents and treats the real diseases of vitamin D lack: rickets in children, osteomalacia in adults. Strongest-evidence item. | high | verified |
| C45 | In older and at-risk people — especially those with low levels, institutionalised, in aged care, or frail — vitamin D, usually paired with calcium, has a modest benefit for preventing fractures. | high | verified |
| C46 | When VITAL looked at fractures in its generally healthy, already-replete participants, it "found no reduction"; that fracture benefit does not extend to healthy, replete adults under 70. | high | verified |
| C47 | The groups for whom a supplement makes real sense = the at-risk list: limited sun / dark or veiled/covered skin; elderly and housebound; malabsorption (coeliac, Crohn's, post-bariatric); structured osteoporosis and fracture-prevention care; exclusively breastfed infants per local guidance. | high | verified |
| C48 | Guidelines describe modest, regular dosing — one amount to correct a genuine deficiency, a smaller one for maintenance — set with a doctor; the benefit evidence sits on modest regular dosing, NOT on giant one-off megadoses, which "have their own troubling signals. | high | verified |
| C49 | Across VITAL and D-Health, extra vitamin D "did not deliver the cancer benefit, the cardiovascular benefit, the mood benefit, the longer-life benefit, or the general-population fracture benefit it was sold on" in replete adults. | high | verified |
| C50 | Genuine open questions remain: specific sub-populations the big trials weren't built to answer cleanly, some unsettled mortality sub-signals, and optimal targets in particular conditions experts still argue about. | low | verified |
| C51 | When UVB light hits skin it kicks off the reaction that makes vitamin D — "sunlight is the main natural source for most people. | high | verified |
| C52 | In Australia UV is strong — "strong enough that the same sun making your vitamin D is also the leading driver of skin cancer" — so sun exposure must be balanced against that risk. | high | verified |
| C53 | Diet contributes a smaller share of vitamin D; sources are a short list: oily fish, eggs, and fortified foods. | low | verified |
| C54 | Most healthy people with reasonable sun exposure don't need to chase a number or a supplement; the people who genuinely warrant assessment are the at-risk groups. | high | verified |
| C64 | VITAL, randomised nearly 26,000 adults and followed them for about five years. | high | verified |
| C65 | VITAL "enrolled ordinary adults from the general population and gave half of them vitamin D3 at 2,000 IU a day (in a design that also tested fish oil at the same time)" — adults not selected for deficiency. | high | verified |
| C66 | D-Health "gave older Australian adults a big monthly dose of 60,000 IU of vitamin D and tracked what happened over years, including who lived and who died. | high | verified |
| C67 | VIDA "is the New Zealand study, which also used a monthly high-dose approach in its population and looked hard at outcomes like heart disease and respiratory infection. | high | verified |
| C68 | A practising doctor reviewed the results and is accountable for what made the page." Doctor is AHPRA-registered Australian, unnamed, unbranded. | low | verified |
| C69 | Michael Holick, a vitamin D researcher, authored the canonical pro-supplement book and is closely associated with the deficiency-panic framing. | low | verified |
| C70 | wording in the book — untabled restatement | — | unsupported → corrected |
Ledger exported 2026-07-23. Found something we still got wrong? Tell us — corrections happen in the open. How the books are made: the honest method.