Let's look at a recent meta-analysis.
A meta-analysis on vitamin D forms has found that vitamin D3 may be more effective than vitamin D2 in raising blood levels of 25-hydroxy vitamin D-the active form of the vitamin.
Interest in comparing vitamin D3 to vitamin D2 has gained momentum largely because vitamin D3 is animal-based whereas vitamin D2 is plant-based. The latter of these ingredients is often used in food fortification because it can reach a greater consumer base, including vegans and vegetarians.
But studies suggest that the body may more efficiently use vitamin D3, including a 2011 study that found significantly longer-lasting levels of 25-hydroxy vitamin D with the D3 form.
A new meta-analysis on vitamin D, published in the American Journal of Clinical Nutrition, analyzed the results of 10 random controlled trials including over 1,000 adults taking vitamin D3 or D2 supplements. When compared to vitamin D2, vitamin D3 showed a significantly increased ability to raise 25-hydroxy vitamin D in blood serum, especially when taken in a bolus dose.
“We know that vitamin D is vital in helping to keep us fit and healthy, but what has not been clear is the difference between the two types of vitamin D,” said lead author Laura Tripkovic of the University of Surrey. “It used to be thought that both were equally beneficial, however our analysis highlights that our bodies may react differently to both types and that vitamin D3 could actually be better for us.”
Since the recent meta-analysis looked only at vitamin D as a dietary supplement, the researchers are now planning a future study on over 300 people consuming the vitamin D forms when added to foods.