Vitamin d2 vs vitamin d3
Pro Research Analysisby 
Searched over 200M research papers
Vitamin D2 vs. Vitamin D3: A Comparative Analysis
Introduction to Vitamin D Forms
Vitamin D is essential for maintaining bone health and supporting various bodily functions. It exists in two primary forms: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Despite their structural similarities, emerging research suggests significant differences in their efficacy and metabolism.
Efficacy in Raising Serum 25-Hydroxyvitamin D Levels
Vitamin D3 Superior in Increasing 25(OH)D
Multiple studies have consistently shown that Vitamin D3 is more effective than Vitamin D2 in raising serum 25-hydroxyvitamin D [25(OH)D] levels. A large randomized controlled trial demonstrated that Vitamin D3 increased vitamin D status by 74-75%, compared to a 33-34% increase with Vitamin D2 over 12 weeks . Similarly, a meta-analysis of randomized controlled trials confirmed that Vitamin D3 significantly outperforms Vitamin D2 in elevating serum 25(OH)D concentrations, especially when administered as a bolus dose 37.
Long-Term Efficacy
Long-term studies also support the superior efficacy of Vitamin D3. Research conducted over the winter months showed that daily supplementation with Vitamin D3 maintained serum 25(OH)D levels more effectively than Vitamin D2, which was associated with a decline in 25(OH)D3 levels . Another study found that Vitamin D3 supplementation resulted in a greater increase in total 25(OH)D compared to Vitamin D2 over an 8-week period .
Metabolic Differences
Impact on Vitamin D Metabolites
Vitamin D2 and D3 also differ in their metabolic pathways. Vitamin D2 has been shown to suppress the serum concentrations of several vitamin D metabolites, including 25(OH)D3 and 1α,25-dihydroxyvitamin D3, while increasing the ratio of 24R,25-dihydroxyvitamin D3 to 25(OH)D3 . In contrast, Vitamin D3 supplementation increases the levels of these metabolites, indicating a more favorable metabolic profile .
Storage and Potency
Vitamin D3 is not only more effective in raising serum levels but also in maintaining them. A study comparing the storage of vitamins in subcutaneous fat found that Vitamin D3 resulted in significantly higher storage levels than Vitamin D2, suggesting greater potency and longer-lasting effects .
Daily vs. Bolus Dosing
The frequency of dosing also influences the efficacy of these vitamins. While Vitamin D3 consistently shows superior results in both daily and bolus dosing, the advantage of Vitamin D3 over Vitamin D2 is more pronounced with bolus dosing . This suggests that Vitamin D3 may be more suitable for less frequent, higher-dose supplementation strategies.
Conclusion
In summary, Vitamin D3 is more effective than Vitamin D2 in raising and maintaining serum 25-hydroxyvitamin D levels, has a more favorable metabolic profile, and results in greater storage within the body. These findings suggest that Vitamin D3 should be the preferred form for supplementation to correct vitamin D deficiency and maintain optimal vitamin D status. Further research is needed to explore the long-term health implications of these differences and to refine public health recommendations accordingly.
Sources and full results
Most relevant research papers on this topic