ergocalciferol
Brand names: Drisdol, Calciferol
Ergocalciferol is a vitamin D2 supplement. It helps your body absorb calcium and phosphorus, which are important for strong bones.
What it does
This medicine treats conditions caused by low vitamin D levels.
Common side effects
No common side effects listed.
Key warnings
The range between helpful and harmful doses is very small.
How It Works
Ergocalciferol is a synthetic form of vitamin D2. It helps your body absorb calcium from the stomach and intestines. It also helps regulate calcium levels in your blood.
How to Take It
Take this medicine exactly as your doctor tells you. The dose will be based on your specific condition. You may need regular blood tests and X-rays while taking this medicine to monitor your progress. Make sure you get enough calcium in your diet.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or breastfeeding. High doses of vitamin D during pregnancy can harm the baby. Talk to your doctor about the risks and benefits.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store at room temperature (77°F), away from light and moisture.
Side Effects (from patient reports)
Based on 240,932 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 366,491 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1999–2025.
Total Reports
366,491
Death-Related Reports
21,613
Hospitalization Reports
98,409
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | FATIGUE | 36,312 |
| 2 | NAUSEA | 27,026 |
| 3 | DIARRHOEA | 25,824 |
| 4 | HEADACHE | 24,768 |
| 5 | DRUG INEFFECTIVE | 24,587 |
| 6 | PAIN | 23,207 |
| 7 | OFF LABEL USE | 21,938 |
| 8 | DYSPNOEA | 19,350 |
| 9 | ARTHRALGIA | 19,251 |
| 10 | DIZZINESS | 18,673 |
| 11 | ASTHENIA | 16,525 |
| 12 | FALL | 16,406 |
| 13 | VOMITING | 15,063 |
| 14 | PAIN IN EXTREMITY | 14,394 |
| 15 | MALAISE | 14,135 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
The range between helpful and harmful doses is very small. Your doctor needs to closely supervise your dosage. Too much vitamin D can cause serious side effects, including kidney problems and tissue damage.
Common Questions
What is the strength of each capsule?
How often will I need blood tests?
Can I take this with other medications?
What should I do if I experience side effects?
How will I know if the medicine is working?
Can I drink alcohol while taking this medicine?
What happens if I take too much?
Is there a generic version of this medicine?
How long will I need to take this medicine?
What should I avoid while taking this medicine?
What drug class is ergocalciferol?
Is ergocalciferol safe during pregnancy?
Has ergocalciferol been recalled?
Active Recalls
Defective Delivery System: Leakage observed after oral solution was repackaged into unit-dose syringes.
Safecor Health, LLC
Related Medications in Vitamin D2 Supplement
Other drugs grouped near ergocalciferol — same-class peers and common alternatives.
ascorbic acid
Vitamin C
This medicine is a Vitamin C supplement.
Compare with ergocalciferol →
biotin
Vitamin B7
Dialyvite with Zinc is a prescription vitamin supplement.
Compare with ergocalciferol →
calcitriol
Rocaltrol
Calcitriol is a form of vitamin D that helps your body absorb and use calcium.
Compare with ergocalciferol →
calcium carbonate
Tums, Caltrate
Calcium carbonate is a medicine that can relieve heartburn and upset stomach.
Compare with ergocalciferol →
cholecalciferol
Vitamin D3
PNV-DHA is a multivitamin with minerals and essential fatty acids.
Compare with ergocalciferol →
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What the FDA Data Shows for ergocalciferol
The FDA label for ergocalciferol (sold under brand names such as Drisdol, Calciferol) classifies it as an over-the-counter product in the Vitamin D2 Supplement class. This medicine treats conditions caused by low vitamin D levels. Labeling covers dosing, contraindications, and monitoring requirements derived from clinical trials.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 240,932 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: January 31, 2025
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages