vitamin D

Medically Reviewed on 11/7/2022

Brand Name: Ergocalciferol (Vitamin D2), Cholecalciferol (Vitamin D3), Cholecalciferol (Vitamin D3)

Generic Name: vitamin D

Drug Class: N/A

What is vitamin D-oral, and how does it work (mechanism of action)?

Vitamin D is a necessary vitamin for the growth and development of bones. Vitamin D is commonly known as ergocalciferol (Vitamin D2) and cholecalciferol (Vitamin D3). Vitamin D2 and D3 are broken down to their active form, calcitriol, in the body. Calcitriol works by increasing the absorption of calcium and phosphorus in the body. Calcitriol also prevents the loss of calcium and phosphorus from kidneys so they are absorbed back into the body to maintain sufficient levels.

Vitamin D is used for treating hypoparathyroidism, vitamin D-resistant rickets, and low vitamin D levels. Over-the-counter Vitamin D preparations are commonly used for low Vitamin D levels.

What brands are names available for vitamin D-oral?

Ergocalciferol (Vitamin D2), Cholecalciferol (Vitamin D3), Cholecalciferol (Vitamin D3)

Is vitamin D-oral available as a generic drug?


Do I need a prescription for vitamin D-oral?

Vitamin D2 and D3 50000 IU are available with a prescription. Vitamin D2 and D3 400 – 5000 IU are available over the counter (OTC).

What are the side effects of vitamin D-oral?

Side effects of Vitamin D include:

What is the dosage for vitamin D-oral?

  • Hypoparathyroidism: Take 25000 to 200000 IU vitamin D by mouth once daily with 4 grams of calcium lactate 6 times daily.
  • Vitamin D resistant rickets: Take 12000 to 500000 IU Vitamin D by mouth once daily.
  • Daily intake of vitamin D: Take 600 IU daily.

Which drugs or supplements interact with vitamin D-oral?

Vitamin D should be used with caution with mineral oil because mineral oil slows down the absorption of Vitamin D and reduces its therapeutic benefits.

Thiazide diuretics like hydrochlorothiazide (Microzide) and chlorthalidone (Thalitone) should be used with caution in people with hypoparathyroid taking Vitamin D, because thiamine diuretics may increase calcium levels.


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Is vitamin D-oral safe to take if I'm pregnant or breastfeeding?

There are no adequate studies done on Vitamin D to determine safe and effective use in pregnant women.

Vitamin D enters breast milk. Therefore, it is best to be cautious before using it in nursing mothers.

What else should I know about vitamin D-oral?

What preparations of vitamin D-oral are available?

PREPARATIONS: Vitamin D2 and D3 are available in 400, 800, 1000, 2000, 2400, and 5000 international units (IU) tablets and capsules. Vitamin D2 is available in 50000 IU (1.25 mg) softgels. Vitamin D3 is available in 50000 IU capsules.

How should I keep vitamin D-oral stored?

Vitamin D capsules and tablets are stored at room temperature between 15 C - 30 C (59 F - 86 F).


Vitamin D (Ergocalciferol [Vitamin D2], Cholecalciferol [Vitamin D3]) is required for the maintanence for bones and teeth. It works to increase absorption of calcium and to prevent its loss through the kidneys.

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Medically Reviewed on 11/7/2022
NIH. Vitamin D.

FDA prescribing references