Ergocalciferol (Vitamin D2)
Ergocalciferol is a fat-soluble vitamin supplement used to treat and prevent vitamin D deficiency, which can lead to conditions such as rickets, osteomalacia, and renal osteodystrophy.
Ergocalciferol is a vitamin D supplement used to treat vitamin D deficiency and support bone health by enhancing calcium absorption.
Key facts at a glance
- ATC
- A11CC01
- RxNorm
- 4018
- Generic
- Ergocalciferol
- Class
- atc-a11
- Brands
- Calcidol, Drisdol
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- oral
- Forms
- capsule, tablet, solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment and prevention of vitamin D deficiency, rickets, osteomalacia (softening of bones), hypoparathyroidism, and renal osteodystrophy. Also used in patients with malabsorption, limited sunlight exposure, or those taking certain anticonvulsant medications that accelerate vitamin D metabolism.
Ergocalciferol is converted in the liver to calcifediol, then further metabolized in the kidneys to calcitriol (the active form). It enhances intestinal absorption of calcium and phosphorus, promotes bone mineralization, and helps maintain normal serum calcium levels essential for bone health and neuromuscular function.
Should be taken with food containing fats for optimal absorption. Calcium levels should be monitored during therapy, as excessive vitamin D can cause hypercalcemia. Patients with hypercalcemia, kidney disease, or sarcoidosis should use with caution. May interact with corticosteroids, seizure medications, and certain diuretics.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy