What is Vitamin D3 (D3 Vitamin)?
Vitamin D3 (cholecalciferol) is a fat-soluble vitamin/pro-hormone that can be synthesized in the skin through the effect of sunlight (UVB). In the body, it is converted to 25(OH)D in the liver and to active 1,25(OH)2D in the kidneys, regulating calcium-phosphorus balance and bone metabolism. Being fat-soluble, it can be stored and may cause toxicity with excessive intake.
- CAS number (main form): 67-97-0
- Molecular formula: C₂₇H₄₄O
- Forms in the catalog: Cholecalciferol, Kingdomway, Cholecalciferol, Garden Biopharma
What is D3 Vitamin Used For? Why is it Used?
D3 vitamin is critical for bone and dental health, calcium balance, muscle, and immune function; deficiency is widespread in the population due to insufficient sun exposure. Cholecalciferol (D3) is preferred over D2 because it is more effective at raising 25(OH)D levels in the blood. Since it is fat-soluble and stored, the dosage must be kept within the UL limit.
Forms and Differences
Vitamin D3 is offered in different chemical forms; the choice of form is made based on bioavailability, stability, and intended use:
- Cholecalciferol (D3): The natural form of vitamin D derived from animal sources and synthesized in the skin via UVB. It is generally more effective than D2 (ergocalciferol) at raising 25(OH)D levels in the blood. It is produced in powder (100,000 IU – 40 MIU/g) and liquid forms.
- Ergocalciferol (D2): A plant/fungi-derived form of vitamin D (for comparison). It is used in vegetarian products; however, it is generally weaker than D3 in raising 25(OH)D levels and persistence in the blood.
- Powder (dry) D3 formulation: Encapsulated in a starch/gelatin matrix, stabilized with antioxidants; suitable for tablets, capsules, and food powders. It is standardized at high potency (e.g., 100,000 IU/g and above).
- Liquid/oil-based D3: D3 dissolved in vegetable oil; used for drop products and oil-based food fortification, with high absorption in the oily matrix.
Use in Dietary Supplements
- Form used: Cholecalciferol (D3) is predominantly used in supplements; it is preferred due to its superiority over D2 in raising blood D levels. Powder forms are for tablets/capsules, and liquid forms are for drop products.
- Dosage and unit: IU and µg are used together (1 µg = 40 IU). Although the NRV is 5 µg (200 IU), current nutritional references recommend higher intakes; products are typically formulated in the range of 400–2,000 IU. The EFSA adult UL value is 100 µg (4,000 IU)/day.
- Who is it for: It is used for individuals with little sun exposure, the elderly, people with dark skin, those with malabsorption, and those with low levels during winter months. In the elderly, it is evaluated for bone health and reducing fall risk.
- Method of intake: Being a fat-soluble vitamin, its absorption improves when taken with a meal containing fat; daily or intermittent (weekly/monthly) high-dose regimens can be used.
Use in the Food Industry
- Fortification: It is used to fortify milk and dairy products, vegetable oils/margarine, breakfast cereals, and plant-based beverages with D3; separate forms are available for liquid oil matrices and dry powders.
- Stability and encapsulation: D3 is sensitive to oxygen, heat, and light; in food production, stability throughout the shelf life is ensured by antioxidant-protected, gelatin/starch microencapsulated beads/powder forms.
- Authorized vitamin source: Cholecalciferol (D3) is an authorized source of vitamin D in EU food supplements and fortification regulations.
Effects on Health
Vitamin D3 is a vitamin that plays a role in many fundamental functions in the body. The main functions authorized/evaluated by the European Food Safety Authority (EFSA):
- Calcium and phosphorus absorption: Vitamin D contributes to the normal absorption/use of calcium and phosphorus (EFSA approved) and helps maintain normal blood calcium levels.
- Normal bones: Vitamin D contributes to the maintenance of normal bones (EFSA approved); it supports bone mineralization by regulating calcium balance.
- Normal teeth: Vitamin D contributes to the maintenance of normal teeth (EFSA approved).
- Muscle function: Vitamin D contributes to the maintenance of normal muscle function (EFSA approved).
- Immune system: Vitamin D contributes to the normal function of the immune system (EFSA approved).
- Cell division: Vitamin D plays a role in the process of cell division (EFSA approved).
Usage Limits in Dietary Supplements
- Nutrient Reference Value (NRV): NRV (1169/2011, Annex XIII): Vitamin D 5 µg (200 IU).
- Upper Intake Level (EFSA): EFSA UL: 100 µg (4,000 IU)/day for adults.
- Turkish legislation (TETGK): Within the scope of the Turkish Dietary Supplements Regulation, vitamin D is an authorized vitamin and must be declared on the label in µg/NRV%; for the exact maximum amount per product, current Regulation annexes and TİTCK guidelines should be taken as reference (a single official number could not be confirmed in this research — no fabricated value has been provided).
Fat-soluble → stored; chronic high doses can lead to hypercalcemia and toxicity. The UL (100 µg/day) should not be exceeded; Vitamins A and D are the fat-soluble vitamins that require the most careful monitoring regarding accumulation/toxicity.
Technical Specifications
| Parameter | Value |
|---|---|
| Purity | ≥100,000 IU/g |
| Appearance | White Flowing Powder |
| Moisture | ≤5.0 % |
| Solubility | Fat Soluble |
Scientific Studies
The following independent studies relate to the bioavailability, use, and effects of this vitamin (study types are specified):
- PubMed 30624670 — Vitamin D supplementation to optimize bone health in the elderly: a randomized controlled trial (VDOP)
- PubMed 37768498 — Effectiveness of vitamin D supplements in reducing fall risk in older adults: a meta-analysis of randomized controlled trials
Technical Documents and Supply — Asuka Kimya
You can contact Asuka Kimya for SDS, TDS, CoA and supply conditions for Vitamin D3.
References
- efsa.onlinelibrary.wiley.com
- efsa.onlinelibrary.wiley.com
- ods.od.nih.gov
- eur-lex.europa.eu
- pubmed.ncbi.nlm.nih.gov
- pubmed.ncbi.nlm.nih.gov
The usage and health information on this page has been compiled from official legislation/institution sources (EFSA, NIH ODS, Turkish Food Codex, EUR-Lex) and independent scientific publications (PubMed). The product is a food supplement/food raw material and does not aim to diagnose or treat diseases.