Vitamin D3 (Cholecalciferol)
Also known as: cholecalciferol, vitamin D, D3
The form of vitamin D the body makes from sunlight and the most effective supplemental form for raising blood levels. It supports calcium absorption, bone health, immune function, and muscle function. Most supplemental D3 is derived from lanolin; a lichen-sourced vegan version exists as a separate ingredient.
Research summary
Converted to calcitriol, a hormone that regulates calcium and phosphate balance and modulates immune cell activity.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 400 IU | 1,000–2,000 IU | 4,000 IU | 4,000 IU |
NIH ODS — UL is 100 mcg (4,000 IU) per day for adults
RDA is 600 IU (15 mcg) for adults and 800 IU (20 mcg) over age 70. Fat-soluble, so absorption improves when taken with a meal containing fat. 40 IU = 1 mcg. Often paired with vitamin K2. dose_max_studied is capped at the 4,000 IU UL for validation; a 3-year randomized trial in healthy adults (Burt 2019) compared 400, 4,000, and 10,000 IU/day under monitoring, so higher amounts have been studied but sit above the UL.
Source material: lanolin
As supplied: Typically supplied as a 100,000 IU/g powder dilution on a carrier; 2,000 IU ≈ 20 mg of powder
Forms of Vitamin D
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| Vitamin D3 (Cholecalciferol) | 1,000–2,000 IU | — | Capsule, Powder, Tablet, Softgel, Gummy, Liquid | low |
| Vitamin D3 (Vegan, Lichen-Sourced) | 1,000–2,000 IU | — | Capsule, Powder, Tablet, Softgel, Gummy, Liquid | mid |
| Vitamin D2 (Ergocalciferol) | 400–2,000 IU | — | Capsule, Powder, Tablet, Softgel, Gummy, Liquid | low |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Formulation notes
Commonly paired with vitamin K2 (MK-7) and magnesium.
- Has an upper limit
Sources
Related ingredients
Vitamin D3 (Vegan, Lichen-Sourced)
VitaminChemically identical cholecalciferol extracted from lichen rather than sheep's wool lanolin, which lets a product carry vegan and vegetarian claims while keeping the D3 form that raises and holds serum 25(OH)D better than D2.
Typical: 1,000–2,000 IU
Cod Liver Oil
Fatty acidCod liver oil is pressed from the livers of Atlantic cod.
Typical: 1,000–2,000 mg
Vitamin D2 (Ergocalciferol)
VitaminErgocalciferol is the plant and fungal form of vitamin D, produced by UV irradiation of ergosterol from yeast or mushrooms.
Typical: 400–2,000 IU
Vitamin C (Ascorbic Acid)
VitaminAscorbic acid is the reference form of vitamin C and the most common form in supplements; NIH ODS notes its bioavailability equals that of vitamin C naturally present in food.
Typical: 250–1,000 mg
Probiotic Blend (Multi-Strain)
ProbioticA generic placeholder for a multi-strain probiotic blend, typically combining several Lactobacillus and Bifidobacterium species and sometimes Streptococcus thermophilus or a Bacillus spore.
Typical: 10–50 B CFU