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 absorption of calcium and phosphorus in the body. Calcitriol also prevents loss of calcium and phosphorus from kidneys so they are absorbed back in the body to maintain sufficient levels.

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

GENERIC AVAILABLE: Yes

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

: 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.

Side effects of Vitamin D include:

• nausea,
• vomiting,
• constipation,
• weight loss,
• weakness, and
• increased calcium levels (hypercalcemia).

• 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.

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.

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 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).