This page shows what was measured, who it was measured in, and what that does not settle.
What Calcitriol does in the body
Low calcium and overactive parathyroid glands caused by kidney failure, and low calcium caused by absent parathyroid hormone
Ordinary vitamin D has to be modified twice before it does anything: once by the liver, once by the kidney. When the kidney fails, the second step stops, and calcium absorption fails with it. This drug is the finished molecule. It enters cells, binds a receptor that sits directly on DNA, and turns on the genes that pull calcium out of food — and turns down the gene that makes parathyroid hormone.
What happened in people
Increased intestinal calcium absorption and reduced serum alkaline phosphatase, stated in the label as the basis of the dialysis indication
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The recorded finding that sits closest to something a person would notice. Written into the record, not signed off, and it carries no population or interval.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
The limit that matters most
That suppressing parathyroid hormone and normalising alkaline phosphatase translates into fewer deaths, fractures or less vascular calcification
Where it acts
The nucleus of the intestinal absorptive cell and of the parathyroid chief cell — a gene switch, not a mineral supplement
Kind of result
A number that stands in for health
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · FXC9231JVH · read 2026-08-29
Its recorded molecular formula is C27H44O3, weighing 416.64.
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
Where each sentence above came from
No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.
Shown as the opening line on this page.
A limit recorded against this substance. Not signed off as a reviewed claim.
The four opening statements run to 111 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Comparator
A comparator is whatever the treatment was measured against.
A picture of it, and where the picture fails
It is like the other runner in a race.
Where that stops being true. A race has one winner. A study can show both arms improved.
What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.
The control condition against which the experimental intervention is assessed.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Absolute difference
An absolute difference is how many more people in a hundred were affected.
A picture of it, and where the picture fails
It is like counting heads in two rooms of a hundred.
Where that stops being true. Heads are easy to count. Study results carry a margin of error too.
What people get wrong. It is confused with a percentage change, which can look far larger.
The arithmetic difference in event rates between arms.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Mortality, cardiovascular outcomes and biochemical markers of mineral metabolism
✗ The study did not show it
Who was studied
Palmer 2007 meta-analysis of vitamin D compounds in chronic kidney disease
How many people
3667
Study design
Systematic review and meta-analysis of 76 randomised controlled trials
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
No reduction in death, bone pain, vascular calcification or parathyroidectomy; hypercalcaemia relative risk 2.37 (95% CI 1.16 to 4.85) for established sterols
Repeated elsewhere
Replicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. Only 8 of 76 trials reported mortality at all, and only 5 directly compared newer with established compounds. The evidence base is large in trial count and thin in outcomes.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral capsule and oral solution; an intravenous form and a topical ointment also exist
Interval reported. 95% CI 1
Written into the record, not signed off as a reviewed claim.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
CMS National Average Drug Acquisition Cost (NADAC) survey — what United States retail pharmacies pay to acquire a drug (https://data.medicaid.gov/dataset/fbb… · a recorded source, not a stored snapshot
New vertebral fracture rate per 100 patient-years
✓ The study showed what it set out to show
Who was studied
Tilyard 1992 — calcitriol against calcium in postmenopausal osteoporosis
How many people
622
Study design
Prospective, multicentre, single-blind, randomised, three years
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Year 3: 9.9 against 31.5 fractures per 100 patient-years, P<0.001; effect confined to women with five or fewer baseline fractures
Repeated elsewhere
Failed to Replicate
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Single-blind, with a comparator-group fracture rate several times higher than placebo arms of contemporaneous osteoporosis trials, and a treatment effect present only in a baseline-severity subgroup. Postmenopausal osteoporosis never became an approved indication.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral capsule and oral solution; an intravenous form and a topical ointment also exist
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
CMS National Average Drug Acquisition Cost (NADAC) survey — what United States retail pharmacies pay to acquire a drug (https://data.medicaid.gov/dataset/fbb… · a recorded source, not a stored snapshot
What we know
RNAWiki holds 2 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Calcitriol
What a person takes: Oral capsule and oral solution; an intravenous form and a topical ointment also exist.
The measurement behind this step
Given by mouth in microgram doses, or intravenously during dialysis where higher doses suppress parathyroid hormone more effectively. A topical form is a separate product for plaque psoriasis and is not interchangeable.
Getting in
Given as the finished hormone because the kidney cannot finish it
Vitamin D needs two chemical changes to work, one in the liver and one in the kidney. When the kidney fails, the second never happens. This capsule is the molecule that would have been made.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Cholecalciferol is 25-hydroxylated in the liver, then 1-alpha-hydroxylated by CYP27B1 in the proximal renal tubule. Loss of functioning tubular mass removes that enzyme, so 25-hydroxyvitamin D accumulates and the active hormone falls. Calcitriol bypasses both steps, which also means it bypasses the feedback that normally regulates the last one.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
Reaching the cell
It enters cells and binds a receptor that lives on DNA
Unlike most drugs it does not act at the cell surface. It travels into the nucleus and binds a protein that is already sitting on the genes it controls.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
The vitamin D receptor is a nuclear hormone receptor. Both the hepatic 25-hydroxyl and the renal 1-alpha-hydroxyl are required for high-affinity binding, which is roughly a thousandfold greater than for 25-hydroxyvitamin D — the structural reason the precursor cannot substitute.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
What it acts on
It pairs with a partner receptor and grips the response element
The drug-bound receptor joins with a partner protein, and the pair clamps onto specific sequences in front of the genes they control.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
The ligand-bound receptor heterodimerises with the retinoid X receptor and occupies vitamin D response elements — direct repeats separated by three nucleotides — recruiting coactivators and the transcriptional machinery.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
The change it makes
In the gut, calcium transport genes switch on
The cells lining the intestine start making the channels and carriers that pull calcium out of food. That is why calcium in blood rises.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Transcription of TRPV6, the apical calcium channel, and of calbindin, the cytosolic buffer that shuttles calcium to the basolateral pump, both rise. Transcellular absorption increases, which the label describes as enhanced calcium absorption and reduced serum alkaline phosphatase.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
The change it makes
In the parathyroid gland, hormone production is switched down
The same receptor in the parathyroid gland does the opposite: it turns the parathyroid hormone gene down. Combined with the rise in blood calcium, that is what relieves the overactive gland.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
The receptor complex acts at a negative vitamin D response element in the parathyroid hormone gene promoter, lowering transcription directly, while the rise in serum calcium suppresses secretion through the calcium-sensing receptor. Both arms converge, which is why hypercalcaemia and parathyroid hormone suppression are inseparable for this molecule.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
What that does for a person
The numbers move; whether anything else does is unresolved
Calcium rises and parathyroid hormone falls, which is what treatment is aimed at. Across seventy-six trials, deaths, bone pain, artery hardening and parathyroid surgery did not fall, and high calcium became more common.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Pooled across 76 randomised trials in 3667 participants, vitamin D compounds did not reduce death, bone pain, vascular calcification or parathyroidectomy; established sterols raised hypercalcaemia (RR 2.37) and hyperphosphataemia (RR 1.77) without a consistent parathyroid hormone reduction. Only 8 trials reported mortality.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 6 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
People with chronic kidney disease before and during dialysis, and people whose parathyroid glands are absent or unresponsive.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What the label states about particular groups
On pediatric, the label states: “The safety and effectiveness of Calcitriol Ointment in pediatric subjects below the age of 2 years has not been established.”
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
On older people, the label states: “Clinical studies of Calcitriol Ointment did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.”
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Available data from pregnancies that occurred during the clinical development of Calcitriol Ointment and published cases of oral and intravenous calcitriol use in pregnant women have not identified a drug associated risk for major birth defects, miscarriages, or adverse maternal or fetal outcomes.”
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary There are no data on the presence of calcitriol in human milk, the effects on the breastfed infant or on milk production after treatment with Calcitriol Ointment.”
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
Where the result stopped carrying
Across 76 randomised trials the class did not reduce death, bone pain, vascular calcification or parathyroidectomy
Established sterols did not show a consistent reduction in parathyroid hormone, the biochemical target they are prescribed to move
Only 8 of 76 trials reported mortality, so the outcome question was largely never asked rather than answered
The 1992 osteoporosis result was never reproduced and never converted into an indication
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Given by a clinician
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral capsule and oral solution; an intravenous form and a topical ointment also exist
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
RNAWiki has not recorded a supervision or regulatory status for this substance.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
No register row and no identity class settled the question.
No source is stored against this line.
What is in the pack
Given by mouth in microgram doses, or intravenously during dialysis where higher doses suppress parathyroid hormone more effectively. A topical form is a separate product for plaque psoriasis and is not interchangeable.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
No boxed warning. The characteristic hazard is hypercalcaemia, and the label states that adverse effects are in general those of excessive vitamin D intake. Early features are weakness, headache, somnolence, nausea, vomiting, dry mouth, constipation, muscle and bone pain, metallic taste and loss of appetite; later features include polyuria, weight loss, ectopic calcification, nephrocalcinosis, hypertension and arrhythmia. Concurrent hypercalcaemia and hyperphosphataemia can cause radiographically visible soft-tissue calcification. Because the biological half-life is short, elevated calcium normalises within days of stopping.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Calcitriol United States prescribing information (openFDA label endpoint) — indications and usage, warnings, adverse reactions (https://api.fda.gov/drug/labe… · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral capsule and oral solution; an intravenous form and a topical ointment also exist
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
A topical form is a separate product for plaque psoriasis and is not interchangeable.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
What is recorded as being sold
58 products list this as an active ingredient in the United States drug directory. 58 of them contain it and nothing else.
FDA National Drug Code directory · 72266-251 · read 2026-08-29
They are sold as capsule, capsule, gelatin coated, capsule, liquid filled, injection, ointment and powder, taken intravenous, oral and topical.
FDA National Drug Code directory · 72266-251 · read 2026-08-29
The regulator's established pharmacologic class for it is cholecalciferol [cs] and vitamin d3 analog [epc].
FDA National Drug Code directory · 72266-251 · read 2026-08-29
32 published labels name it as an active ingredient. 32 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · cdcaffc6-e14e-4607-b77b-fc78a8382f60 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · cdcaffc6-e14e-4607-b77b-fc78a8382f60 · read 2026-08-29
5 marketed supplement labels list this ingredient, classed as vitamin.
Those labels carry all other, nutrient and structure/function claims. A claim of that kind is written by the manufacturer and is not assessed by any regulator, so its presence says nothing about whether it is true.
calcitriol is topical at 3 DOSAGE FORMS AND STRENGTHS Ointment, 3mcg/g., recorded as fda label in effect 2023-01-31 in the United States.
US prescribing information · 7fa4ab07-3d8e-4300-91f3-b1e17cba8691 · read 2026-08-30
Recorded price in US: 0.15764–0.23874 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 15 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..
Recorded source · 2026-08-26 · read 2026-08-28
Recorded price in US: 6.79324 USD per one millilitre, across 2 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..
Recorded source · 2026-08-26 · read 2026-08-28
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.
Questions worth asking
Which of the trials of Calcitriol studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That suppressing parathyroid hormone and normalising alkaline phosphatase translates into fewer deaths, fractures or less vascular calcification
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That calcitriol is a treatment for postmenopausal osteoporosis, which is not an approved indication and rests on one unreplicated single-blind trial
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the newer analogues are safer, when the pooled hypercalcaemia relative risk against placebo was higher for them, at 5.15, than for the established sterols
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That ordinary vitamin D supplements do the same thing — they cannot, because the missing activation step is the one the kidney performs
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Calcitriol are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
Seventy-six trials, and no demonstrated benefit to a patient
In plain words
All the randomised trials of vitamin D drugs in kidney disease were pooled: seventy-six of them, in 3667 people. They did not reduce deaths, bone pain, hardening of arteries or the need for parathyroid surgery. They roughly doubled the chance of a high calcium level.
What was measured
Hypercalcaemia relative risk 2.37 (95% CI 1.16 to 4.85) for established sterols; no reduction in death, bone pain, vascular calcification or parathyroidectomy across 76 trials
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Palmer and colleagues identified 76 randomised controlled trials of vitamin D compounds in chronic kidney disease enrolling 3667 participants. The compounds did not reduce the risk of death, bone pain, vascular calcification or parathyroidectomy. Against placebo, established vitamin D sterols — the group calcitriol belongs to — increased hypercalcaemia (relative risk 2.37, 95% CI 1.16 to 4.85) and hyperphosphataemia (relative risk 1.77, 95% CI 1.15 to 2.74) and did not show a consistent reduction in parathyroid hormone. Newer analogues did reduce parathyroid hormone (weighted mean difference -10.77 pmol/L, 95% CI -20.51 to -1.03) but were associated with hypercalcaemia at a relative risk of 5.15 (1.06 to 24.97). Only 8 of the 76 trials reported mortality. The authors concluded that vitamin D compounds do not consistently reduce parathyroid hormone and that beneficial effects on patient-level outcomes are unproven.
Written into the record, not signed off as a reviewed claim
It is prescribed to move a number, and the number is not the outcome
In plain words
Treatment is guided by parathyroid hormone levels in blood. Bringing that number down is what the drug is judged on. Whether doing so makes anyone live longer, break fewer bones or feel better has not been established.
What was measured
That normalising parathyroid hormone and alkaline phosphatase translates into fewer fractures, less vascular calcification or longer life — the surrogate is measured routinely and the outcome has not been demonstrated
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The label defines the predialysis indication around a serum intact parathyroid hormone level of 100 pg/mL or above as strongly suggestive of secondary hyperparathyroidism, and describes the dialysis indication in terms of enhanced calcium absorption, reduced serum alkaline phosphatase, possible reduction of parathyroid hormone and the histological manifestations of osteitis fibrosa cystica. Every one of those is a laboratory or histological measure. The pooled trial evidence found only 8 of 76 trials reported mortality at all, and found no reduction in bone pain, the one patient-level outcome that was reported. Treating a biochemical target is a reasonable clinical strategy in the absence of outcome trials; it is not the same as having them.
Written into the record, not signed off as a reviewed claim
The 1992 osteoporosis trial was never replicated and never led to an indication
In plain words
A New Zealand trial in 622 women reported that this drug cut spinal fractures dramatically compared with calcium alone. It was only single-blind, the comparison group fractured at an extraordinary rate, the effect appeared only in a subgroup, and it never became an approved use.
What was measured
That calcitriol is an osteoporosis treatment — a single-blind trial against a calcium comparator with an implausibly high event rate, positive only in a subgroup, that no regulator converted into an indication
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Tilyard and colleagues randomised 622 postmenopausal women with one or more vertebral compression fractures to calcitriol 0.25 micrograms twice daily or 1 g of elemental calcium daily for three years, in a single-blind multicentre study. New vertebral fractures were 9.3 against 25.0 per 100 patient-years in year two and 9.9 against 31.5 in year three, P<0.001. The effect was present only in the subgroup with five or fewer vertebral fractures at baseline, where the figures were 5.2 against 25.3 and 4.2 against 31.0. Peripheral fractures were 11 in 11 women against 24 in 22 women, P<0.05. Three features limit it: single-blind design in a fracture trial read radiographically, a calcium-group fracture rate several times higher than in contemporaneous placebo arms of other osteoporosis trials, and a treatment effect confined to a baseline-severity subgroup. Postmenopausal osteoporosis is not an approved indication for calcitriol in the United States, and the result has not been reproduced at that magnitude.
Written into the record, not signed off as a reviewed claim
Hypercalcaemia is common and the label quantifies it
In plain words
In the hypoparathyroidism studies, about one in three patients had a high calcium level at least once and about one in seven had too much calcium in the urine. About one in six had a rise in a kidney blood test.
What was measured
Hypercalcaemia in about 1 in 3 patients, hypercalciuria in about 1 in 7, elevated serum creatinine in about 1 in 6, in the hypoparathyroidism programme
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The label reports that in clinical studies in hypoparathyroidism and pseudohypoparathyroidism, hypercalcaemia was noted on at least one occasion in about one in three patients and hypercalciuria in about one in seven, while elevated serum creatinine was observed in about one in six, roughly half of whom had normal values at baseline. Where hypercalcaemia and hyperphosphataemia coexist, soft-tissue calcification can occur and can be seen radiographically. In patients with normal renal function, chronic hypercalcaemia may itself raise serum creatinine. Because the drug has a short biological half-life, calcium normalises within a few days of withdrawal, much faster than after vitamin D3 preparations.
Source
Calcitriol United States prescribing information, Adverse Reactions and Warnings (openFDA label endpoint)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
This is a gene switch, not a mineral
In plain words
The drug does not carry calcium into the body. It binds a receptor that sits on DNA and turns on the genes for the transporters that carry calcium across the gut wall, and turns down the gene for parathyroid hormone.
What was measured
Roughly thousandfold higher vitamin D receptor affinity than 25-hydroxyvitamin D, requiring both the hepatic 25- and renal 1-alpha hydroxyls
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Calcitriol binds the vitamin D receptor, which heterodimerises with the retinoid X receptor and occupies vitamin D response elements in target gene promoters. In intestinal epithelium this raises transcription of the apical calcium channel TRPV6 and of the cytosolic shuttle calbindin, increasing transcellular calcium absorption. In the parathyroid chief cell the same complex acts on a negative response element in the parathyroid hormone gene, suppressing its transcription — which is the basis of the secondary hyperparathyroidism indication and, in the same action, of the hypercalcaemia risk. The label describes the drug as the active hormone exerting vitamin D activity, and describes its adverse effects as in general those of excessive vitamin D intake.
Source
Calcitriol United States prescribing information, Indications and Usage and Adverse Reactions (openFDA label endpoint)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
How many documents were read
27 documents were read for this substance.
RNAWiki source record
22 of them state the same halfLife, and they agree.
RNAWiki source record
Where else this substance is registered
FDA substance identifier (UNII)
FXC9231JVH
RxNorm concept
308867
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Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
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Safety mode resolved
No register row and no identity class settled the question.
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Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
23 approved applications cover products containing this substance. The earliest was NDA018044, approved 19780817 to ESJAY PHARMA.
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What is not here
7 questions this page could not answer
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How close this is to real life — found nothing in the sources checked.
Felt, measured, or meaningful — found nothing in the sources checked.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
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Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
The finished, kidney-activated form of vitamin D given as a drug when the kidney can no longer make it — a nuclear receptor ligand that switches on calcium-absorption genes in the gut and switches off parathyroid hormone transcription in the gland, and whose class, across 76 randomised trials in 3667 people, did not reduce death, bone pain, vascular calcification or parathyroidectomy while roughly doubling the risk of hypercalcaemia.
Recorded evidence blocks (9)
Q1
On the Calcitriol label: indicated for what?
"Predialysis Patients Calcitriol capsules are indicated in the management of secondary hyperparathyroidism and resultant metabolic bone disease in patients with moderate to severe chronic renal failure (Ccr 15 to 55 mL/min) not yet on dialysis. In children, the creatinine clearance value must be corrected for a surface…": indications and usage on Calcitriol's label. DailyMed label · bf621b22-b783-416f-aee3-e0dbfdb782ca · 2026-07-15
Q2
128 registered trials of Calcitriol — at which phases?
Registered studies posting no result
85 of 128
128 registered studies of Calcitriol: 40 phase2, 33 phase4, 23 na, 21 phase1, 12 phase3, 5 early phase1, 1 na or unstated. CLINICALTRIALS_SNAPSHOT · 2026-09-01
620 with a PubMed record
Show the evidence
phase2
40
phase4
33
na
23
phase1
21
phase3
12
early phase1
5
6 more recorded rows
na or unstated
1
completed
78
unknown
22
terminated
21
withdrawn
4
recruiting
3
recorded 2026-09-01 · last checked 2026-09-04
Q3
23 of Calcitriol's trials stopped: safety, futility/efficacy, accrual/recruitment, funding/business, other?
safety (2), futility/efficacy (1), accrual/recruitment (6), funding/business (5) and other (9): Calcitriol's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"Lack of funds"; 23 of 128 registered studies
Show the evidence
Trial
NCT00004468
withdrawn; "Lack of funds"
NCT00084864
terminated; "sample size is too small to draw a conclusion"
NCT00118066
terminated; "Slow accruaL, lack of scientific progress"
NCT00273338
terminated; "DSMB"
NCT00383487
terminated; "Extreme toxicity"
NCT00459563
withdrawn; "Inadequate enrollment"
14 further recorded trials
NCT00486512
terminated; "The overall program was terminated"
NCT00508898
withdrawn; "Funding problem; trial abandoned."
NCT00524589
terminated; "closed due to futility"
NCT00536991
terminated; "difficult to recruit"
NCT00585442
terminated; "Lack of quality data"
NCT00623974
terminated; "Terminated due to slow accrual."
NCT00664430
terminated; "Low enrollment rate"
NCT01026363
withdrawn; "Inadequate enrollment"
NCT01093092
terminated; "Study transferring to INOVA Health"
NCT01134315
terminated; "Terminated after FDA agreement."
NCT01725113
terminated; "Nationwide shortage of study meds in 2013 loss of funding \& competing studies"
NCT02410005
terminated; "Logistic challenges"
NCT02859896
terminated; "The study was conducted to fulfill a post-marketing commitment (PMC).FDA acknowledged the fulfillment of this PMC."
NCT03261336
terminated; "can not meet enrollment"
recorded 2026-09-01 · last checked 2026-09-04
Q4
Human studies of Calcitriol used Calcitriol 3mcg/g — over how long?
Human studies of Calcitriol used "Calcitriol 3mcg/g". ClinicalTrials.gov · 2026-09-01
11 recorded entries; human; also "0.5 mg calcitriol (1a -25-dihydroxycholecalciferol)", "placebo to 0.5 mg calcitriol (1a -25-dihydroxycholecalciferol)", "Compound 31543 Calcitriol 5 μg/mL"
5 to 8 hours; The elimination half-life of calcitriol in serum after single oral doses is about 5 to 8 hours in normal subjects.
metabolismpharmacokinetics
Metabolism In vivo and in vitro studies indicate the presence of two pathways of metabolism for calcitriol.
recorded 2026-07-15 · last checked 2026-09-04
Q6
Which 40 trials of Calcitriol posted no result?
Posted no result
40 of 40 completed trials
Registrations
NCT00004402, NCT00006275, NCT00000412, NCT00010231, NCT00004043 and NCT00601328, and 34 more
Completion dates
oldest 2000-06; newest 2024-07-31
Show the evidence
Trial
NCT00004402
2000-06
NCT00006275
2000-07
NCT00000412
2002-04
NCT00010231
2002-11
NCT00004043
2003-03
NCT00601328
2003-08
14 further recorded trials
NCT00008086
2004-09
NCT00004928
2004-10
NCT00009802
2005-06
NCT00054522
2006-03
NCT00017576
2006-07
NCT00182741
2006-08
NCT00238199
2006-08
NCT00560300
2006-11
NCT00084708
2007-05
NCT00319761
2007-09
NCT00763503
2009-02
NCT00030069
2009-05
NCT00800358
2009-12
NCT01205880
2010-01
Q7
At the median, Calcitriol's trials enrolled 40 people — anything larger?
Median enrolment
40
Largest enrolment
2200
Registered trials counted
124
Q8
What do 986 spontaneous reports say about Calcitriol — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Calcitriol appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 986 reaction mentions were counted: hypercalcaemia 265; pain 118; acute kidney injury 91; hospitalisation 87. FAERS via Open Targets · CHEMBL846 · 2026-06-24
Show the evidence
hypercalcaemia
265
pain
118
acute kidney injury
91
hospitalisation
87
macular degeneration
78
hypertension
73
4 more recorded rows
abdominal discomfort
73
milk-alkali syndrome
72
gastrooesophageal reflux disease
70
confusional state
59
recorded 2026-06-24 · last checked 2026-09-04
Q9
Which 10 reactions does Calcitriol's label not list?
ChEMBL 37 — CC BY-SA 3.0 Unported · ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 7 source rows
✓ no critical contamination: no quarantine open
✓ canonical metadata passed: slug and display name present
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