What is vitamin d2
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Understanding Vitamin D2: Sources, Efficacy, and Comparisons
What is Vitamin D2?
Vitamin D2, also known as ergocalciferol, is a form of vitamin D that is primarily derived from plant sources and fungi, such as mushrooms. It is structurally similar to vitamin D3 but differs in its origin and some aspects of its metabolism and efficacy in the human body 14.
Sources and Metabolism of Vitamin D2
Vitamin D2 is obtained from dietary sources, particularly mushrooms and fortified foods. Once ingested, it undergoes a series of hydroxylation reactions in the liver and kidneys to become biologically active. The enzyme CYP109E1, for instance, has been shown to catalyze the hydroxylation of vitamin D2 at specific positions, resulting in metabolites like 24(R),25-diOH VD2, which have potential bioactive properties .
Efficacy of Vitamin D2 vs. Vitamin D3
Comparative Effectiveness
There has been considerable debate regarding the efficacy of vitamin D2 compared to vitamin D3. Some studies suggest that vitamin D2 is as effective as vitamin D3 in maintaining serum 25-hydroxyvitamin D levels. For example, a study found that a daily dose of 1000 IU of vitamin D2 was equally effective as 1000 IU of vitamin D3 in maintaining serum 25-hydroxyvitamin D levels over an 11-week period . However, other research indicates that vitamin D3 is more potent and effective in raising and maintaining these levels 579.
Meta-Analyses and Systematic Reviews
Systematic reviews and meta-analyses have generally concluded that vitamin D3 is more effective than vitamin D2. One meta-analysis found that vitamin D3 supplementation resulted in significantly higher serum 25-hydroxyvitamin D levels compared to vitamin D2 . Another study highlighted that vitamin D3 was more effective in increasing vitamin D status, particularly when administered in food fortification strategies .
Biological Potency and Storage
Vitamin D3 has been shown to be approximately 87% more potent than vitamin D2 in raising and maintaining serum 25-hydroxyvitamin D concentrations. It also results in greater storage of vitamin D in body fat . This increased potency and storage capacity make vitamin D3 a preferred option for supplementation and fortification .
Conclusion
Vitamin D2, derived from plant sources, plays a crucial role in maintaining vitamin D levels in the body. However, evidence suggests that vitamin D3 is more effective in raising and maintaining serum 25-hydroxyvitamin D levels. Despite this, both forms of vitamin D are important, and the choice between them may depend on specific health needs, dietary preferences, and availability.
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