What is the difference between vitamin d2 and d3
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Differences Between Vitamin D2 and D3
Introduction to Vitamin D Forms
Vitamin D is essential for maintaining healthy bones and supporting immune function. It exists in two primary forms: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Despite their similar roles in the body, emerging research indicates significant differences in their efficacy and biological impact.
Potency and Efficacy of Vitamin D2 vs. D3
Vitamin D3 is More Potent
Multiple studies have demonstrated that Vitamin D3 is more effective than Vitamin D2 in raising and maintaining serum 25-hydroxyvitamin D [25(OH)D] levels. For instance, a study comparing the two forms found that Vitamin D3 increased serum 25(OH)D levels by 45 ng/ml, whereas Vitamin D2 only increased it by 24 ng/ml over a 12-week period1. Another meta-analysis confirmed that Vitamin D3 supplementation resulted in significantly higher serum 25(OH)D concentrations compared to Vitamin D22.
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. Participants taking Vitamin D3 had stable 25(OH)D levels, while those taking Vitamin D2 experienced a significant decline9.
Biological Activity and Metabolism
Differential Metabolic Effects
Vitamin D2 and D3 also differ in their metabolic pathways. Vitamin D3 supplementation increases serum concentrations of various metabolites, including 25(OH)D3, 24R,25(OH)2D3, and 1α,25(OH)2D3. In contrast, Vitamin D2 supplementation tends to suppress these metabolites and increase the ratio of 24R,25(OH)2D3 to 25(OH)D3, indicating a different metabolic impact5.
Bioavailability
The bioavailability of Vitamin D3 is generally higher than that of Vitamin D2. A study involving healthy volunteers showed that Vitamin D3 supplementation led to a more significant increase in total 25(OH)D levels compared to Vitamin D2, which was associated with a decrease in 25(OH)D3 levels6.
Practical Implications
Supplementation Recommendations
Given the greater potency and efficacy of Vitamin D3, it is often recommended as the preferred form for supplementation. This is particularly important for individuals with Vitamin D deficiency, as Vitamin D3 can more effectively raise and maintain adequate serum 25(OH)D levels1 2 3.
Cost and Availability
Vitamin D3 is not only more effective but also generally more cost-effective than Vitamin D2. This makes it a more practical choice for both healthcare providers and patients when addressing Vitamin D deficiency1.
Conclusion
In summary, while both Vitamin D2 and D3 play crucial roles in maintaining Vitamin D levels, Vitamin D3 is significantly more potent and effective in raising and maintaining serum 25(OH)D concentrations. Its superior bioavailability and metabolic effects make it the preferred choice for supplementation. Future research may further elucidate the distinct metabolic pathways and long-term health impacts of these two forms of Vitamin D.
Sources and full results
Most relevant research papers on this topic
Vitamin D(3) is more potent than vitamin D(2) in humans.
D3 is 87% more potent in raising and maintaining serum 25(OH)D concentrations and produces 2- to 3-fold greater storage of vitamin D than equimolar D2, making it the preferred treatment option for vitamin D deficiency.
RCT
Very Rigorous Journal
Highly CitedComparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis
Vitamin D3 supplementation is more effective at raising serum 25-hydroxyvitamin D concentrations than vitamin D2, potentially making it the preferred choice for supplementation.
Meta-AnalysisVery Rigorous JournalHighly CitedVitamin D2 vs. vitamin D3: They are not one and the same
Vitamin D3 is more than twice as effective as vitamin D2 at raising vitamin D levels, when given at a low dose in a physiologically relevant and public health-friendly manner.
Meta-AnalysisVitamin D2 vs. vitamin D3: Are they one and the same?
Vitamin D2 and D3 may have distinct and significant differences in efficacy, potentially impacting vitamin D status and calcium absorption.
Differential Effects of Oral Boluses of Vitamin D2 vs Vitamin D3 on Vitamin D Metabolism: A Randomized Controlled Trial
Oral bolus vitamin D2 is less effective than vitamin D3 in elevating total serum 25(OH)D concentration, and may have different effects on vitamin D metabolism.
RCT
Rigorous JournalBioavailability of vitamin D(2) and D(3) in healthy volunteers, a randomized placebo-controlled trial.
Vitamin D3 increases total 25(OH)D concentration more than vitamin D2, while vitamin D2 supplementation leads to a decrease in 25(OH)D3, explaining the different effect on total 25(OH)D.
RCTRigorous JournalHighly CitedEvidence that vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2.
Vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than vitamin D2, challenging the assumption that they have equal nutritional value in humans.
Non-RCTHighly CitedUrinary metabolic profiles after vitamin D2 versus vitamin D3 supplementation in prediabetes
Vitamin D2 and D3 supplementation do not result in different urinary metabolite profiles, supporting no biological difference between the two vitamins in prediabetes patients.
RCTRigorous JournalLong-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months
Daily vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over winter months in healthy adults.
RCTVery Rigorous JournalHighly CitedRelative Efficacy of Vitamin D2 and Vitamin D3 in Improving Vitamin D Status: Systematic Review and Meta-Analysis
Cholecalciferol is more effective than ergocalciferol in improving vitamin D status and regulating PTH levels, regardless of participant demographics, dosage, and supplementation vehicle.
Meta-AnalysisVery Rigorous Journal