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Ergocalciferol

Ergocalciferol is vitamin D2, taken by mouth as a capsule to treat hypoparathyroidism, refractory (vitamin D resistant) rickets, and familial hypophosphatemia.

Brand names DrisdolCalcidolVitamin D
Drug class Provitamin D2 Compound
Rx Form 1
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 31 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

How we combine label and product data →
✓No current FDA shortage listed · checked Oct 3, 2026
Ergocalciferol at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written
Ergocalciferol is a prescription vitamin D used to treat hypoparathyroidism, vitamin D resistant rickets, and familial hypophosphatemia. It works well only when the dose is carefully individualized, because too much can cause toxic high calcium. Take it exactly as prescribed and keep your lab and X-ray appointments.
How we write & review this content — our editorial policy →
How you get itPrescription only
Comes asCapsule
Earliest FDA record1974
Companies listing it with the FDA33
FDA label last updatedSep 4, 2026
FDA’s strongest warning (boxed)None on the label

Patient information guide — a plain-language walkthrough of Ergocalciferol, written from its FDA label.

What Ergocalciferol is used for

▾

Ergocalciferol capsules are used for three conditions. Every product covered here lists the same uses.

  • Hypoparathyroidism
  • Refractory rickets (vitamin D resistant rickets)
  • Familial hypophosphatemia

How Ergocalciferol works

▾

Ergocalciferol is vitamin D2. The liver and then the kidneys convert it into its active forms. Those forms help the small intestine absorb calcium and phosphorus, which raises blood levels enough to allow bone mineralization.

They also pull calcium and phosphate from bone and probably help the kidneys hold on to calcium. Parathyroid hormone regulates the kidney step.

Ergocalciferol dosage

▾

Ergocalciferol is taken by mouth as a capsule, generally once daily. Your prescriber sets the dose based on your condition and adjusts it with close monitoring.

  • The gap between a helpful and a toxic dose is narrow.
  • People with hypoparathyroidism may also be given calcium lactate along with it.
  • Get enough calcium in your diet.
  • Expect blood calcium and phosphorus tests every 2 weeks or more often, and monthly bone X-rays until things are stable.

Always follow your prescriber's directions and the label.

Dosing details from the FDA-approved label

From the Ergocalciferol prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Vitamin D Resistant Rickets
    • 12,000 to 500,000 IU units daily
  • Hypoparathyroidism
    • 50,000 to 200,000 IU units daily concomitantly with calcium lactate 4 g, six times per day
Read the label’s full dosing text

DOSAGE AND ADMINISTRATION THE RANGE BETWEEN THERAPEUTIC AND TOXIC DOSES IS NARROW. Vitamin D Resistant Rickets: 12,000 to 500,000 USP units daily. Hypoparathyroidism: 50,000 to 200,000 USP units daily concomitantly with calcium lactate 4 g, six times per day. DOSAGE MUST BE INDIVIDUALIZED UNDER CLOSE MEDICAL SUPERVISION. Calcium intake should be adequate. Blood calcium and phosphorous determinations must be made every 2 weeks or more frequently if necessary. X-rays of the bones should be taken every month until condition is corrected and stabilized.

Read the full Dosage and Administration section on DailyMed →

Ergocalciferol side effects

▾

Common side effects

  • Nausea
  • Loss of appetite
  • Constipation
  • Weight loss
  • Vague aches, stiffness and weakness

When to get medical help

  • Call your doctor if you have excessive thirst, frequent urination, or need to urinate at night. These can be signs of too much vitamin D.
  • Get medical help for nausea, weakness, loss of appetite, constipation, or weight loss that persists or worsens. These can be signs of high calcium.
  • Seek urgent care for confusion, stupor, or dehydration, which can signal a high-calcium emergency.
  • Tell your doctor about new high blood pressure or changes in kidney function.

Most side effects come from too much vitamin D and high blood calcium.

  • Nausea
  • Loss of appetite
  • Constipation
  • Weight loss
  • Vague aches, stiffness and weakness

Call your doctor promptly if you notice heavy thirst, frequent urination, or kidney problems. Too much vitamin D can also cause high blood pressure and calcium deposits in soft tissues.

Ergocalciferol warnings and precautions

▾
  • Vitamin D toxicity: The dose range between helpful and toxic is narrow.
  • Kidney and heart effects: Too much can damage the kidneys. It can cause calcium deposits in the heart, blood vessels, and lungs. Rarely, it can be fatal.
  • Lingering effects: Effects can last two or more months after stopping.
  • Infants: Infants with idiopathic hypercalcemia may be sensitive to vitamin D.
  • Keep out of the reach of children.

Ergocalciferol interactions

▾

Two interactions are named on the label.

  • Mineral oil: It interferes with absorption of fat-soluble vitamins, including vitamin D.
  • Thiazide diuretics: In people with hypoparathyroidism taking ergocalciferol, they may cause high blood calcium.

Interactions listed in the FDA-approved label

From the Ergocalciferol prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • Mineral oil: Mineral oil interferes with the absorption of fat-soluble vitamins, including vitamin D preparations.
  • Thiazide diuretics: Administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with ergocalciferol may cause hypercalcemia.
Read the label’s full interactions text

Drug Interactions Mineral oil interferes with the absorption of fat-soluble vitamins, including vitamin D preparations. Administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with ergocalciferol may cause hypercalcemia.

Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

Check Ergocalciferol against a supplement or herb →

Before taking Ergocalciferol

▾
  • Do not use it with high blood calcium (hypercalcemia).
  • Do not use it with a malabsorption syndrome.
  • Do not use it with hypervitaminosis D or abnormal sensitivity to vitamin D's toxic effects.
  • Infants with idiopathic hypercalcemia need vitamin D strictly restricted.
  • Tell your prescriber about all your medicines, especially water pills and mineral oil.

Ergocalciferol overdose

▾

Too much vitamin D causes high blood calcium. Signs include poor appetite, nausea, weakness, weight loss, constipation, heavy thirst, and frequent urination. Treatment means stopping the vitamin right away, eating a low-calcium diet, and drinking plenty of fluids. Severe cases with dehydration, stupor, or coma need hospital care. Recovery is usual if no permanent damage has occurred.

What Ergocalciferol does in the body

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Active vitamin D metabolites raise blood calcium and phosphate by increasing absorption from the intestine. They also mobilize calcium and phosphate from bone. This supports bone mineralization.

How your body processes Ergocalciferol

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The liver first converts ergocalciferol to 25-hydroxyvitamin D. The kidneys then convert it to the active 1,25-dihydroxyvitamin D. Because of these steps, there is a 10 to 24 hour delay before it starts working. Its effects can last two or more months after treatment stops.

How to store Ergocalciferol

▾

Store at 25° C (77° F); excursionns permitted to 15° - 30° C (59° - 86° F) Protect from light and moisture. Dispense in a tight, light-resistant container as defined in the USP.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

Ergocalciferol: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Ergocalciferol — the kind of thing our pharmacy team would talk through with you at the counter.

What is ergocalciferol for?

▾
It is vitamin D2, and it is prescribed for hypoparathyroidism, vitamin D resistant rickets, and familial hypophosphatemia. Your doctor will explain which one applies to you.

How should I take it?

▾
Take it by mouth as a capsule, exactly as your prescriber directs. Your dose is individualized, so don't change it on your own. Make sure you get enough calcium, and keep your blood test and X-ray appointments.

Why do I need so many blood tests?

▾
The safe range for vitamin D is narrow, and too much can raise your calcium too high. Blood calcium and phosphorus are checked every 2 weeks or more often. Bone X-rays are done monthly until you are stable.

What side effects should I watch for?

▾
Nausea, poor appetite, constipation, weight loss, and vague aches or weakness can signal too much vitamin D. Heavy thirst and frequent urination are also warning signs. Call me or your doctor if you notice these.

Can I take it with other medicines?

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Tell us about everything you take. Thiazide water pills can raise calcium too high if you have hypoparathyroidism. Mineral oil can also reduce vitamin D absorption.

Who shouldn't take it?

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You should not take it if you have high blood calcium, trouble absorbing nutrients, too much vitamin D already, or unusual sensitivity to vitamin D. Keep the capsules away from children.

Is Ergocalciferol available over the counter?

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Ergocalciferol is dispensed by prescription according to its FDA labeling, so it isn't sold over the counter. Your prescriber and pharmacist will determine if it's appropriate for you.

When was Ergocalciferol first available?

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Ergocalciferol has been available in the United States since at least 1974, based on FDA approval history (Drugs@FDA) and product marketing records.

Who makes Ergocalciferol?

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Ergocalciferol is supplied by 33 manufacturers listed in the FDA NDC Directory, including Bryant Ranch Prepack, Aphena Pharma Solutions - Tennessee, LLC, Remedyrepack Inc..

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Ergocalciferol on HelloPharmacist

🌿Drug & Supplement CheckerErgocalciferol vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Ergocalciferol NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Ergocalciferol Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Ergocalciferol forms and strengths (how it comes)

Ergocalciferol is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Capsule

By mouth
Brands Drisdol Vitamin D
How this form is used
What it may be used for
  • Drisdol is used to treat hypoparathyroidism, refractory (vitamin D resistant) rickets, and familial hypophosphatemia.
  • Ergocalciferol capsules are used for the same three conditions.
  • Vitamin D capsules (ergocalciferol) are used for the same three conditions.
Important instructions
  • Drisdol is taken by mouth, and the dose is individualized under close medical supervision.
  • Ergocalciferol capsules are taken by mouth, with blood calcium and phosphorus checked every 2 weeks or more often.
  • Ergocalciferol (Vitamin D2) capsules call for adequate calcium intake and monthly bone X-rays until the condition is stable.
Available strengths 2 strengths
1.25 mg 50000 [IU]
91 FDA-listed product records ⓘ

Ergocalciferol on the U.S. market: products, makers and brands

How Ergocalciferol appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

33 companies list 94 Ergocalciferol product records with the FDA, mostly as capsule; the earliest marketing or approval year on record is 1974. Brand names on the directory include Drisdol, Calcidol, Vitamin D; the rest are generics.

1
Dose forms ⓘ
33
Labelers (makers, repackagers, distributors)
4
Brand names
94
FDA-listed product records ⓘ
1974
Earliest FDA record ⓘ

Also listed with the FDA, not a patient dose form: Powder (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Bryant Ranch Prepack17%
Aphena Pharma Solutions - Tennessee, LLC9%
Remedyrepack Inc.9%
PD-Rx Pharmaceuticals, Inc.6%
NuCare Pharmaceuticals,Inc.6%
Advanced Rx Pharmacy of Tennessee, LLC3%
Other makers50%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

How widely Ergocalciferol is used (Medicaid data)

A general measure of how commonly Ergocalciferol is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Ergocalciferol is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

7,906,448
Medicaid prescriptions filled (Q1–Q4 2025)
$64.3M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Ergocalciferol prescribed? Of the 1,600 medications we measure, Ergocalciferol ranks #17 by Medicaid prescriptions — more than 99% of them.

Where Ergocalciferol ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #17 of 1,600
#12 Hydroxyzine 9,012,994 Rx #13 Sertraline 8,868,838 Rx #14 Omeprazole 8,598,486 Rx #15 Amphetamine / Amphetam... 8,570,176 Rx #16 Amlodipine 8,001,920 Rx #17 Ergocalciferol 7,906,448 Rx #18 Trazodone 7,898,849 Rx #19 Levothyroxine 7,786,593 Rx #20 Acetaminophen 7,225,940 Rx #21 Buprenorphine / Naloxo... 6,982,290 Rx #22 Lisinopril 6,788,371 Rx

Utilization by Ergocalciferol product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

ergocalciferol 1.25 MG Oral Capsule

7,906,448 Medicaid prescriptions (Q1–Q4 2025) 100% of Ergocalciferol prescriptions shown $64.3M gross reimbursement (before rebates) ≈ $8.14 per prescription (gross)

Summed across the 7 of 179 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1367410

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Ergocalciferol, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 7 of 179 listed Ergocalciferol NDCs with Medicaid activity.

Compare Ergocalciferol products

A representative set of FDA-listed product records for Ergocalciferol — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 94 of 94 products — FDA National Drug Code Directory. See every product, package size and price: browse all 94 Ergocalciferol NDCs →

Ergocalciferol recall history

A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.

The FDA’s enforcement reports list no Ergocalciferol recalls since July 2021.

✅No Ergocalciferol recalls on record since July 2021

Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Ergocalciferol RxCUI 4018 3 dose forms · 7 strengths
  1. Dose form (SCDF) Oral Capsule RxCUI 372035 In current FDA listings
    Clinical drug / strength (SCD) 0.05 MG RxCUI 2044659 1.25 MG RxCUI 1367410
  2. Dose form (SCDF) Oral Solution RxCUI 372039 No current FDA listing
    Clinical drug / strength (SCD) 0.2 MG/ML RxCUI 237723
  3. Dose form (SCDF) Oral Tablet RxCUI 372040 No current FDA listing
    Clinical drug / strength (SCD) 0.01 MG RxCUI 199832 0.05 MG RxCUI 1233664 0.25 MG RxCUI 107263 1.25 MG RxCUI 310142

Look up RxCUI 4018 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

Ergocalciferol brand names

Ergocalciferol is sold under 3 brand names in the FDA directory — Drisdol, Calcidol, Vitamin D. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Drisdol Calcidol Vitamin D

Who makes Ergocalciferol: manufacturers and labelers

33 companies list Ergocalciferol products with the FDA. By number of product records, the largest are Bryant Ranch Prepack, Aphena Pharma Solutions - Tennessee, LLC, Remedyrepack Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Bryant Ranch Prepack 16 Aphena Pharma Solutions - Tennessee, LLC 8 Remedyrepack Inc. 8 PD-Rx Pharmaceuticals, Inc. 6 NuCare Pharmaceuticals,Inc. 6 Advanced Rx Pharmacy of Tennessee, LLC 3 Torrent Pharmaceuticals Limited 3 AvPAK 3 Bionpharma Inc. 3 Preferred Pharmaceuticals, Inc. 3 NuCare Pharmaceuticals, Inc. 3 Validus Pharmaceuticals LLC 2 A-S Medication Solutions 2 Strides Pharma Science Limited 2 St. Mary's Medical Park Pharmacy 2 Proficient Rx LP 2 Alembic Pharmaceuticals Inc. 2 Golden State Medical Supply, Inc. 2 AvKARE 2 Denton Pharma, Inc. dba Northwind Pharmaceuticals 2 Catalent Pharma Solutions, LLC 2 Professional Compounding Centers of America dba PCCA 1 American Health Packaging 1 Synthesia, a.s. 1

…and 9 more on the FDA NDC directory.

Ergocalciferol drug class (RxNorm)

Ergocalciferol belongs to the Provitamin D2 Compound class.

Pharmacologic class Provitamin D2 Compound
Drug family (ATC) Vitamin D and analogues

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Ergocalciferol page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Sep 4, 2026
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Ergocalciferol.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Ergocalciferol after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
31
NDC products indexed
94
Distinct labelers/manufacturers represented
33
Linked representative label ⓘ
Torrent Pharmaceuticals Limited
Linked label effective
Sep 4, 2026
Composite sections available
15
Linked SPL Set ID
4ae38744-020d-4c37-a6f1-88f55c2f1047
Linked SPL Document ID
b427fa56-1a5b-4826-9034-e82c697381d3
Open the linked representative label on DailyMed ↗
NDC package records associated with this linked SPL 1

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Torrent Pharmaceuticals Limited is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →