Ergocalciferol
Ergocalciferol, also known as Vitamin D2, is a form of vitamin D used to treat or prevent vitamin D deficiency and related conditions such as rickets (softening of bones in children), osteomalacia (softening of bones in adults), and certain types of hypoparathyroidism. Ergocalciferol is used for Vitamin D deficiency, Hypoparathyroidism and Osteomalacia.
Also called: Kalcipos (United Kingdom)
Pronunciation: er-goe-kal-SIF-er-ol.
- Generic name
- Ergocalciferol
- Brand names
- Ergocal, Ostoforte, Ergocalciferol, D-Vi-Sol, Deltalin, D-Vita
- Drug class
- Vitamin D analog
Availability and supply rules vary by country
Trade names by country: United States · United Kingdom
Australia: · Full directory
What Ergocalciferol is and how it works
Ergocalciferol, also known as Vitamin D2, is a form of vitamin D used to treat or prevent vitamin D deficiency and related conditions such as rickets (softening of bones in children), osteomalacia (softening of bones in adults), and certain types of hypoparathyroidism. It is also used in patients with chronic kidney disease to help maintain healthy calcium and phosphate levels. Vitamin D2 works by helping your body absorb calcium and phosphorus, which are essential for building and maintaining strong bones. It is usually prescribed when dietary intake or sunlight exposure is insufficient, or when the body cannot properly convert vitamin D to its active form. Key points for patients: Take this medication exactly as prescribed, do not exceed the recommended dose, and inform your healthcare provider about all other medications and supplements you are taking. Regular monitoring of blood calcium and vitamin D levels may be necessary.
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Ergocalciferol works
Ergocalciferol (vitamin D2) is a fat-soluble vitamin that is converted in the liver to 25-hydroxyergocalciferol and then in the kidneys to its active form, 1,25-dihydroxyergocalciferol. The active metabolite increases intestinal absorption of calcium and phosphate, promotes bone mineralization, and reduces parathyroid hormone (PTH) secretion.
What is Ergocalciferol used for?
Vitamin D deficiency
Vitamin D deficiency
Hypoparathyroidism
Hypoparathyroidism
Osteomalacia
Osteomalacia
Before taking Ergocalciferol
Do not take / not appropriate for
- Contraindicated in patients with hypercalcemia, vitamin D toxicity, or hypersensitivity to ergocalciferol. (Contraindication)
Tell your clinician about
Ergocalciferol dosage and how to take it
- General Instructions: Take ergocalciferol exactly as prescribed by your healthcare provider. Do not take more than the recommended dose.. Adult Dosing: Typical adult dose for vitamin D deficiency: 50,000 IU orally once weekly for 6–8 weeks, then maintenance dosing as directed. Dosing may vary based on indication and patient needs.. Pediatric Dosing: Dosing in children is weight- and age-dependent. Always follow pediatrician instructions. For rickets: 12,000–500,000 IU orally as a single or divided dose, depending on severity.. Administration: Take with or without food. For best absorption, some providers recommend taking with a meal containing fat. Oral solution should be measured carefully using a dosing syringe or cup.. When To Stop: Do not stop taking without consulting your healthcare provider. Therapy may be discontinued if blood calcium becomes too high or if directed by your doctor.. Storage: Store at room temperature away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician.
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 resume your regular schedule. Do not take an extra dose to catch up.
Overdose
Symptoms of overdose may include severe nausea, vomiting, loss of appetite, excessive thirst, frequent urination, confusion, muscle weakness, weight loss, or bone pain. Seek emergency medical attention if overdose is suspected.
Ergocalciferol side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Vomiting
Incidence: Reported in the clinician-authored database; frequency not established
Constipation
Incidence: Reported in the clinician-authored database; frequency not established
Loss of appetite
Incidence: Reported in the clinician-authored database; frequency not established
Unusual tiredness
Incidence: Reported in the clinician-authored database; frequency not established
Muscle weakness
Incidence: Reported in the clinician-authored database; frequency not established
Headache
Incidence: Reported in the clinician-authored database; frequency not established
Metallic taste
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
Seek urgent medical care for chest pain or feeling short of breath, which can be signs of a serious reaction or dangerously high calcium levels — serious
Symptoms: Seek urgent medical care for chest pain or feeling short of breath, which can be signs of a serious reaction or dangerously high calcium levels.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
High doses can cause serious side effects, including hypercalcemia — serious
Symptoms: High doses can cause serious side effects, including hypercalcemia. Monitor blood calcium and vitamin D levels regularly. Use caution in patients with kidney disease or stones. May interact with certain medications (e.g., thiazide diuretics, digoxin). Not for use in patients with vitamin D toxicity or hypercalcemia.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindicated in patients with hypercalcemia, vitamin D toxicity, or hypersensitivity to ergocalciferol. Use caution in patients with renal impairment, nephrolithiasis, or granulomatous diseases (e.g., sarcoidosis), as these conditions may increase the risk of hypercalcemia.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Ergocalciferol may interact with medications such as thiazide diuretics (increased risk of hypercalcemia), digoxin (increased risk of arrhythmias), anticonvulsants (may reduce vitamin D effectiveness), and corticosteroids (may reduce vitamin D absorption). Always inform your healthcare provider about all medicines and supplements you are taking. | |
| Antacids and mineral supplements | Take ergocalciferol about 2 hours apart from antacids or other mineral supplements, since these can reduce vitamin D absorption. |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Normal supplemental doses are generally considered safe in pregnancy, but taking too much vitamin D could harm an unborn baby, and dosing needs may differ during pregnancy. Tell your healthcare provider if you are or could become pregnant so your dose can be individualized.
Breastfeeding
Ergocalciferol passes into breast milk. High maternal doses could affect a nursing infant, so discuss breastfeeding plans with your healthcare provider before starting or continuing high-dose therapy.
Children
Frequency: Not recommended for pediatric use.. Weight Based: Not established; safety and efficacy not established in children.. Max Daily Dose: Not recommended for pediatric use.. Max Single Dose: Not recommended for pediatric use.. Age Restrictions: Safety not established in children.
Renal Impairment
The FDA label warns that excessive vitamin D (hypervitaminosis D) can impair renal function, causing polyuria, nocturia, polydipsia, hypercalciuria, reversible azotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or irreversible renal insufficiency that may result in death — so patients with kidney disease need closer monitoring of blood calcium during high-dose therapy. The label does not describe a separate hepatic-impairment adjustment, but notes that dosing in elderly patients (who more often have reduced hepatic, renal, or cardiac function) should generally start at the low end of the range. Discuss any kidney or liver condition with your prescriber before starting high-dose ergocalciferol.
Hepatic Impairment
The FDA label warns that excessive vitamin D (hypervitaminosis D) can impair renal function, causing polyuria, nocturia, polydipsia, hypercalciuria, reversible azotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or irreversible renal insufficiency that may result in death — so patients with kidney disease need closer monitoring of blood calcium during high-dose therapy. The label does not describe a separate hepatic-impairment adjustment, but notes that dosing in elderly patients (who more often have reduced hepatic, renal, or cardiac function) should generally start at the low end of the range. Discuss any kidney or liver condition with your prescriber before starting high-dose ergocalciferol.
Monitoring
Storage
Store at room temperature, away from moisture, heat, and light. Keep out of reach of children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Vitamin D deficiency
Dose summary: The standard adult dosing for vitamin D deficiency is 800 to 2000 IU daily.
Renal context: No formal renal dose-adjustment schedule is given, but the FDA label specifically warns that hypervitaminosis D (from excessive dosing) can impair renal function — polyuria, nocturia, polydipsia, hypercalciuria, reversible azotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or irreversible renal insufficiency that may result in death — so patients on high therapeutic doses should have blood calcium monitored frequently, with extra caution in patients with pre-existing renal impairment.
Hepatic guidance
The FDA label does not describe a dedicated hepatic-impairment dosing adjustment for ergocalciferol. It notes only that elderly patients — who more often have reduced hepatic, renal, or cardiac function — should generally have dose selection start at the low end of the range, with the treating clinician using clinical judgment for patients with significant hepatic impairment.
Frequently asked questions
What is ergocalciferol / vitamin D2 used for?
It is used to treat or prevent vitamin D deficiency, rickets, osteomalacia, and certain types of hypoparathyroidism. It may also be used in chronic kidney disease to help manage calcium and phosphate levels.
How should I take ergocalciferol?
Take it exactly as prescribed, with or without food. Some providers recommend taking it with a meal containing fat for better absorption. Use the dosing device provided for liquid forms.
What are the signs of too much vitamin D2?
Symptoms of overdose or toxicity include nausea, vomiting, loss of appetite, excessive thirst, frequent urination, confusion, and muscle weakness. Seek medical attention if these occur.
Can I take ergocalciferol with other supplements?
Do not take additional vitamin D or calcium supplements unless directed by your healthcare provider, as this can increase the risk of side effects.
Is ergocalciferol safe during pregnancy or breastfeeding?
It is generally considered safe when used as directed, but always consult your healthcare provider before use during pregnancy or breastfeeding.
How long does it take to work?
Improvement in vitamin D levels and symptoms may take several weeks. Your doctor may monitor your blood levels to assess response.
What should I do if I miss a dose?
Take the missed dose as soon as you remember, unless it is almost time for your next dose. Do not take an extra dose to make up for a missed one.
What happens if I take too much Ergocalciferol / Vitamin D2?
Taking too much Ergocalciferol / Vitamin D2 can lead to vitamin D toxicity, characterized by symptoms such as nausea, vomiting, weakness, and hypercalcemia. Severe cases can result in kidney damage and heart rhythm problems. If you suspect an overdose, seek immediate emergency medical attention.
Can I drink alcohol while taking Ergocalciferol / Vitamin D2?
While there isn't a direct contraindication, excessive alcohol consumption can impair the body's ability to absorb and utilize vitamin D, potentially reducing the effectiveness of Ergocalciferol. It's generally advisable to moderate alcohol intake and discuss any concerns with your healthcare provider to ensure optimal treatment outcomes.
Is Ergocalciferol / Vitamin D2 safe during pregnancy?
The safety of Ergocalciferol / Vitamin D2 during pregnancy is categorized as 'Consult doctor.' This means that while vitamin D is essential during pregnancy, the appropriate dosage and necessity for supplementation should be determined by a healthcare professional. Always consult your doctor before taking any medication while pregnant.
What is the mechanism of action of Ergocalciferol?
Ergocalciferol (vitamin D2) is a fat-soluble vitamin that is converted in the liver to 25-hydroxyergocalciferol and then in the kidneys to its active form, 1,25-dihydroxyergocalciferol. The active metabolite increases intestinal absorption of calcium and phosphate, promotes bone mineralization, and reduces parathyroid hormone (PTH) secretion.
What is the generic name of Ergocalciferol?
The generic name is Ergocalciferol. It is sold under brand names including Ergocal, Ostoforte, Ergocalciferol, D-Vi-Sol, Deltalin, D-Vita.
What class of drug is Ergocalciferol?
Ergocalciferol is classed as: Vitamin D analog.
References
- Ergocalciferol: MedlinePlus Drug InformationMedlinePlus, U.S. National Library of Medicine · United States · dated 2018-08-15 · accessed 2026-10-13 · source 1
- ERGOCALCIFEROL capsule (FDA prescribing information)U.S. National Library of Medicine DailyMed · United States · accessed 2026-10-13 · source 2
Brand names by country
Single-ingredient Ergocalciferol names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Vitamin Dcapsule, capsule, liquid filled · 1.25 mg · remedyrepack inc.regulator source
- Ergocalciferol (Vitamin D2)capsule · 1.25 mg · advanced rx pharmacy of tennessee, llcregulator source
United Kingdom
- Eciferol D2reference source
- Valupak Calcium & Vitamin Dreference source
- HealthAid Vitamin Dreference source
- Kalcipos-Dreference source
- Ergo-D2reference source
- Ergoral D2reference source
- CalciErgoreference source