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Drug interactions between D3 and Vitamin D2

Results for the following 2 drugs:
D3 (cholecalciferol)
Vitamin D2 (ergocalciferol)

Interactions between your drugs


ergocalciferol cholecalciferol

Applies to: Vitamin D2 (ergocalciferol) and D3 (cholecalciferol)

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Due to a narrow therapeutic index, vitamin D analogs given in combination with each other or with pharmacologic doses of vitamin D may demonstrate additive effects resulting in toxicity manifested as hypercalcemia, hypercalciuria, and hyperphosphatemia. Progressive hypercalcemia due to overdosage of vitamin D and its metabolites can be dangerous and sufficiently severe as to require emergency attention. Acute hypercalcemia may exacerbate tendencies for cardiac arrhythmias and seizures and may potentiate the action of digitalis drugs. Chronic hypercalcemia can lead to generalized vascular calcification, nephrocalcinosis, and calcifications of the cornea or other soft tissues. Immobilized patients are particularly vulnerable to the risk of hypercalcemia.

MANAGEMENT: Vitamin D analogs should not be used in combination with each other or with pharmacologic doses of vitamin D. Serum calcium and phosphorus levels must be closely monitored during therapy with a vitamin D analog, especially early in treatment during dosage adjustment. The serum calcium X phosphorus product should be maintained at less than 55 in patients with chronic kidney disease and should not be allowed to exceed 70 in any patient. An estimate of daily dietary calcium intake should be made and the intake adjusted when indicated. Patients should be advised to avoid an abrupt increase in dietary calcium intake, as it may trigger hypercalcemia, and to contact their physician if they experience early symptoms of vitamin D intoxication associated with hypercalcemia such as weakness, fatigue, headache, somnolence, vertigo, tinnitus, anorexia, nausea, vomiting, constipation, dry mouth, metallic taste, muscle pain, bone pain, ataxia, and hypotonia. Late symptoms may include polyuria, polydipsia, weight loss, nocturia, conjunctivitis, photophobia, rhinorrhea, pruritus, hyperthermia, decreased libido, and cardiac arrhythmias. Radiographic evaluation of suspect anatomical regions may be useful in the early detection of hypercalcemia. If hypercalcemia develops, treatment with vitamin D and any calcium product should be stopped immediately.


  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. "Product Information. Hectorol (doxercalciferol)." Genzyme Corporation, Cambridge, MA.
  3. "Product Information. One-Alpha (alfacalcidol)." Pharmel Inc, Montreal, IN.
  4. "Product Information. Rocaltrol (calcitriol)." Roche Laboratories, Nutley, NJ.
  5. "Product Information. Zemplar (paricalcitol)." Abbott Pharmaceutical, Abbott Park, IL.
View all 5 references

Drug and food interactions

No results found in our database - however, this does not necessarily mean no interactions exist. Always consult with your doctor or pharmacist.

Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.


Vitamin d analogs

Therapeutic duplication

The recommended maximum number of medicines in the 'vitamin d analogs' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'vitamin d analogs' category:

  • D3 (cholecalciferol)
  • Vitamin D2 (ergocalciferol)

Note: The benefits of taking this combination of medicines may outweigh any risks associated with therapeutic duplication. This information does not take the place of talking to your doctor. Always check with your healthcare provider to determine if any adjustments to your medications are needed.

Drug Interaction Classification

The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No information available.

Do not stop taking any medications without consulting your healthcare provider.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.