Vitamin D3 (Immune)
The sunshine vitamin, crucial for a well-regulated and effective immune response.
Also known as: Cholecalciferol
Overview
Vitamin D is a fat-soluble vitamin that functions like a hormone in the body. While known for its role in bone health, it is also a critical modulator of the immune system. Many immune cells have vitamin D receptors, and deficiency is linked to increased susceptibility to infection.
Key Benefits
Enhances Innate Immunity
Stimulates the production of antimicrobial peptides like cathelicidin in response to pathogens.
Regulates Adaptive Immunity
Helps to prevent an overactive immune response and may reduce the risk of autoimmunity by promoting regulatory T-cells.
Reduces Risk of Respiratory Infections
Meta-analyses show that vitamin D supplementation can protect against acute respiratory tract infections, especially in those who are deficient.
Dosage & How to Take
Dosage should ideally be based on blood levels (25-hydroxyvitamin D). A common maintenance dose is 1,000-2,000 IU daily.
| Purpose | Dose | Notes |
|---|---|---|
| General Health | 1,000-2,000 IU/day | Sufficient for most people to maintain adequate levels. |
| Correcting Deficiency | 5,000 IU/day or higher | Should be done under medical supervision with blood testing. |
Best Time to Take
Take with your largest meal of the day or a meal that contains fat to maximize absorption.
With or Without Food
Yes, it is fat-soluble and requires dietary fat for proper absorption.
Forms & Bioavailability
| Form | Absorption | Best For | Notes |
|---|---|---|---|
| Vitamin D3 (Cholecalciferol) | High | General supplementation | The most effective form, identical to what the body produces from sunlight. |
| Vitamin D2 (Ergocalciferol) | Lower | Vegetarian/vegan sources | Less effective at raising blood levels compared to D3. |
Side Effects & Safety
Common
- None at standard doses.
Rare
- Toxicity (hypercalcemia) is possible with extremely high, prolonged doses (>10,000 IU/day), leading to nausea, weakness, and kidney problems.
Contraindications
- Individuals with conditions causing hypercalcemia (e.g., primary hyperparathyroidism) should use with caution.
Interactions
Can impair vitamin D metabolism.
Scientific Research
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall.
Food Sources
Products With Vitamin D3 (Immune)
6 products in our database contain this ingredient
Frequently Asked Questions
Medical Disclaimer
This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.