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Ergocalciferol

Generic name: ergocalciferol (vitamin D2)

Brand names: Calcidol, Calciferol, Drisdol, Vitamin D2

Last updated November 2, 2026 0 views
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What is ergocalciferol?

Ergocalciferol is vitamin D2. Vitamin D helps your body take in calcium.

Ergocalciferol is used to treat hypoparathyroidism (when the parathyroid glands do not work well).

Ergocalciferol is also used to treat rickets (softening of the bones caused by vitamin D deficiency) or low levels of phosphate in the blood (hypophosphatemia).

Ergocalciferol may also be used for reasons not mentioned in this medication guide.

This section was rewritten for readability and reviewed for meaning.

How should I take ergocalciferol?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use only the recommended dose of ergocalciferol.

It may be best to take ergocalciferol after a meal, but you may take ergocalciferol with or without food.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

You will need frequent medical tests.

Your doctor may begin to reduce your ergocalciferol dose as your condition improves. Carefully follow all instructions about adjusting your dose. In some cases, there may be a very small difference in amount between safe and dangerous doses of this medicine.

Your doctor will determine how long to treat you with this medicine.

Ergocalciferol may be only part of a complete program of treatment that also includes dietary changes and taking calcium and vitamin supplements. Follow your doctor's instructions very closely.

Learn about the foods you should eat to make sure you get enough calcium and vitamin D in your diet. Your ergocalciferol dose may need to be adjusted as you make changes to your diet.

Store at room temperature away from moisture, heat, and light.

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Warnings

You should not take ergocalciferol if you have ever had an allergic reaction to vitamin D, if you have high levels of calcium or vitamin D in your body, or if you have a condition that makes it difficult for your body to absorb nutrients from food (malabsorption).

Use only the recommended dose of ergocalciferol. Taking too much could lead to serious or life-threatening side effects.

This section was rewritten for readability and reviewed for meaning.

Before taking this medicine

You should not take ergocalciferol if you have had an allergic reaction to vitamin D, or if you have:

  • high levels of vitamin D in your body (hypervitaminosis D);
  • high levels of calcium in your blood (hypercalcemia); or
  • any condition that makes it hard for your body to absorb nutrients from food (malabsorption).

Tell your doctor if you have ever had:

  • heart disease;
  • kidney disease; or
  • an electrolyte imbalance.

Certain forms of ergocalciferol may contain ingredients you should know about, such as peanut or soybean oil, sugar, aspartame (phenylalanine), or certain food dyes. Ask a doctor before using ergocalciferol if you have allergies, diabetes, or phenylketonuria (PKU).

Too much vitamin D could harm an unborn baby, and your dose needs may be different during pregnancy. Tell your doctor if you are pregnant or if you become pregnant while taking ergocalciferol.

Ergocalciferol can pass into breast milk and may cause side effects in the nursing baby. Tell your doctor if you are breast-feeding.

Do not give ergocalciferol to a child without medical advice. Your child's dose will depend on age, weight, diet, and other factors.

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Ergocalciferol side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking ergocalciferol and call your doctor right away if you have:

  • chest pain or feel short of breath;
  • growth problems (in a child taking ergocalciferol); or
  • early signs of vitamin D overdose--weakness, metallic taste in your mouth, weight loss, muscle or bone pain, constipation, nausea, and vomiting.

Less serious side effects may happen more often, and you may have none at all.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You can report side effects to the FDA at 1-800-FDA-1088.

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What happens if I miss a dose?

Take the medicine as soon as possible, but skip the missed dose if it is nearly time for your next dose. Do not take two doses at the same time.

This section was rewritten for readability and reviewed for meaning.

What happens if I overdose?

Seek emergency medical help or call the Poison Help line at 1-800-222-1222. Taking too much vitamin D can lead to serious or life-threatening side effects.

Signs of an overdose may include nausea, not feeling hungry, feeling very thirsty, urinating more or less than usual, body aches, stiffness, confusion, or having an irregular heartbeat.

Talk to a doctor or pharmacist before taking any multivitamins, mineral supplements, or antacids while you are taking ergocalciferol.

This section was rewritten for readability and reviewed for meaning.

What other drugs will affect ergocalciferol?

Certain medications can make it harder for your body to absorb vitamin D. If you take other medications, take them at least 2 hours before or 2 hours after you take ergocalciferol.

Tell your doctor about all your other medicines, especially:

  • a diuretic or "water pill"; or
  • mineral oil (sometimes taken as a laxative).

This list is not complete. Other drugs may affect ergocalciferol, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

This section was rewritten for readability and reviewed for meaning.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.