Quick Reference
- Scientific Rating
-
5.0/ 5.0
- Primary Mechanism
- Regulates gene expression via the Vitamin D Receptor (VDR)
- Standardized Form
- Cholecalciferol (derived from lanolin or lichen)
Vitamin D3 (cholecalciferol) is the form of vitamin D naturally produced in human skin upon exposure to UVB sunlight, and is also the form most commonly used in supplementation due to its superior effect on raising and maintaining blood levels compared to vitamin D2. Functionally, it behaves more like a hormone than a classic vitamin, regulating calcium and phosphate absorption in the gut, a process essential for maintaining bone density and structure. Its receptors are also present throughout immune cells, which has driven substantial research interest into its broader role in immune regulation, particularly given how common insufficient blood levels are in populations with limited sun exposure. Deficiency is typically identified through a blood test measuring 25-hydroxyvitamin D, the storage form of the vitamin.
Table of Contents
Clinical Summary
A crucial secosteroid hormone essential for calcium absorption, bone health, immune system regulation, and mood. Widespread global deficiency makes supplementation highly beneficial for general populations.
Dosage Guidelines
1,000 to 4,000 IU daily for maintenance. Higher doses (up to 10,000 IU) may be required for clinical deficiency, ideally guided by 25(OH)D blood tests.
Safety & Side Effects
Extremely safe at recommended doses. Chronic, extreme excess can lead to hypercalcemia (toxic calcium buildup).
Known Interactions
May interact with corticosteroids, weight-loss drugs (orlistat), and thiazide diuretics.
Scientific References
Medical Disclaimer
The information provided in this clinical review is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
*These statements have not been evaluated by the Food and Drug Administration (FDA). This product or ingredient is not intended to diagnose, treat, cure, or prevent any disease.
Always consult your physician or other qualified health provider with any questions you may have regarding a medical condition, or before beginning any new diet, fitness, supplement, or treatment regimen, especially if you have pre-existing medical conditions or are taking prescribed medications.
