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Overview: Ergocalciferol is taken for health conditions related to low vitamin D levels. Common side effects may include constipation or feeling tired. Serious side effects are rare with ergocalciferol. It is possible to have too much vitamin D in your blood. It is important to keep all appointments for lab work while you are taking ergocalciferol. Labs help your health care provider make sure you are getting the right amount of ergocalciferol, but not too much. 

Uses

What is ergocalciferol used for?

Ergocalciferol is commonly taken by certain people with the following health conditions related to low vitamin D levels.

Ergocalciferol may also be taken for other conditions as determined by your health care provider.

How does ergocalciferol work (mechanism of action)?

Ergocalciferol, which is a form of vitamin D, helps increase your vitamin D levels. Vitamin D helps your body absorb calcium from foods and supplements, which can help with rickets and hypoparathyroidism. It also helps your body maintain normal phosphate levels, which helps with hypophosphatemia.

How is ergocalciferol supplied (dosage forms)?

Brands and other names

  • Drisdol

Dosage forms and strengths

  • 50,000 IU oral capsules

Ergocalciferol, also known as vitamin D2, and another form of vitamin D (cholecalciferol or vitamin D3) are available as a dietary supplement in various strengths and dosage forms to increase vitamin D levels. See Vitamin D Supplements for more information.

How should I store ergocalciferol?

Ergocalciferol should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). It can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect it from light. 

Side Effects

What are the most common side effects of ergocalciferol?

The most common side effect of ergocalciferol is constipation. Tell your health care provider if you have constipation that bothers you.

There may be other side effects of ergocalciferol that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of ergocalciferol?

While less common, the most serious side effects of ergocalciferol are described below, along with what to do if they happen.

Severe Allergic Reactions. Ergocalciferol may cause allergic reactions, which can be serious. Stop taking ergocalciferol and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use ergocalciferol?

Allergies to Ingredients. People who are allergic to any of the following should not take ergocalciferol.

  • Drisdol
  • Ergocalciferol
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific ergocalciferol products they stock.

High Calcium Levels. You should not take ergocalciferol if you have high calcium levels. Vitamin D helps your body absorb calcium. Taking vitamin D when you have high calcium levels could make your calcium levels too high. 

Vitamin D Toxicity. You should not take ergocalciferol if your vitamin D levels are too high (also known as hypervitaminosis D). 

What should I know about ergocalciferol before using it?

If ergocalciferol was prescribed to you by a health care provider, take it as prescribed. If you are taking over-the-counter ergocalciferol, follow the instructions that come with the product. 

Your health care provider may give you guidance about your diet (more calcium, less phosphate) to follow or other medicines or supplements (phosphate binders, calcium supplements) to take while you are taking ergocalciferol. It is important to follow all health care provider instructions, so that ergocalciferol works for you.

Keep all appointments to have your blood checked while you are taking ergocalciferol. Lab work helps your health care provider make sure you are getting enough ergocalciferol, but not getting too much. Ergocalciferol is a form of vitamin D. You get vitamin D from several places, including the sun, foods, and other vitamins or supplements. Many multivitamins and combination supplement products have vitamin D in them. It is important not to take too much vitamin D. Too much vitamin D can be harmful (hypervitaminosis D). If you are not sure how much vitamin D you need or if you need a vitamin D supplement, talk to your health care provider. 

Do not share ergocalciferol that was prescribed for you by a health care provider with other people, even if they have the same condition as you. It may harm them.

Keep ergocalciferol out of the reach of children.

What should I tell my health care provider before using ergocalciferol?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if ergocalciferol is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

Malabsorption Syndrome. You may have trouble absorbing ergocalciferol if you have malabsorption syndrome. Malabsorption means your body is not able to absorb and use the nutrients that you take by mouth or from the foods you eat. Talk with your health care provider about checking your blood levels of this vitamin.

Certain Allergies. Tell your health care provider if you are allergic to aspirin or tartrazine (a yellow dye). Some ergocalciferol products may contain tartrazine. If you are allergic to aspirin, you may be more likely to be allergic to tartrazine. 

Other Medicines and Supplements. Ergocalciferol may interact with other medicines and supplements. Before taking ergocalciferol, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how ergocalciferol could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will let you know if you should take ergocalciferol while you are pregnant or trying to get pregnant.

Breastfeeding. Ergocalciferol passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should take ergocalciferol while breastfeeding.

Interactions

Does ergocalciferol interact with foods or drinks?

You should take ergocalciferol with food or a meal that has fat in it. Ergocalciferol is a fat-soluble vitamin. Taking it with fat helps your body to absorb it. 

It is unknown if drinking alcohol will affect ergocalciferol.

Does ergocalciferol interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking ergocalciferol.

  • Orlistat (Alli, Xenical), which is a medicine used for weight loss
  • A statin, such as atorvastatin (Lipitor and others) or rosuvastatin (Crestor), which is a medicine to lower cholesterol
  • A thiazide diuretic, such as hydrochlorothiazide, chlorthalidone, or indapamide, which is a medicine commonly used to lower blood pressure

This may not be a complete list of medicines that can interact with ergocalciferol. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much ergocalciferol?

If you or someone else has taken too much ergocalciferol, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of ergocalciferol?

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 only take the next dose. Do not take double or extra doses.