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VitaminsPregnancy Safe

Vitamin D3 (Cholecalciferol)

Also known as: cholecalciferol, sunshine vitamin

Vitamin D3 is the most bioavailable form of vitamin D, produced naturally in the skin upon sun exposure. It plays a critical role in calcium absorption, bone health, immune function, and mood regulation.

Key Benefits

  • Supports calcium absorption and bone health
  • Enhances immune system function
  • May improve mood and reduce risk of depression
  • Supports muscle function
  • May reduce risk of certain cancers

Recommended Dosage

General Use
600-2000 IU daily
Upper Limit
4000 IU daily (some researchers suggest up to 10,000 IU is safe)
Deficiency
5000-50,000 IU under medical supervision

Forms & Bioavailability

Best Forms

  • ✓Cholecalciferol (D3)
  • ✓Calcifediol (25-hydroxyvitamin D)

Forms to Avoid

  • ✗Ergocalciferol (D2) — less potent and shorter-lasting

Safety Notes

  • Fat-soluble — can accumulate to toxic levels
  • Toxicity risk above 60,000 IU/day long-term
  • May interact with steroids, weight-loss drugs, and cholesterol medications
  • Blood levels should be monitored at high doses

Drug Interactions

Consult your healthcare provider if you take any of the following:

Thiazide diureticsSteroidsOrlistatStatins

Sources

  • • NIH Office of Dietary Supplements
  • • Endocrine Society Clinical Guidelines

Top Vitamin D3 (Cholecalciferol) Supplements

Swanson Vitamin D3 1000 IU

Swanson

55
gummy·1000 IU
USP VerifiedNon-GMO Project VerifiedGMP Certified
Added Sugars

Dymatize Vitamin D3 5000 IU

Dymatize

48
softgel·5000 IU
Non-GMO Project Verified
Not Third Party Tested

Source Naturals Vitamin D3 10000 IU

Source Naturals

40
liquid·10000 IU
Not Third Party Tested

Rainbow Light Vitamin D3 2000 IU

Rainbow Light

44
tablet·2000 IU
Non-GMO Project VerifiedGMP Certified
Not Third Party TestedProprietary Blend