People taking vitamin D2 supplements may unintentionally lower their vitamin D3 levels, which is more efficient in fighting off viruses and bacteria.
Vitamin D3 is the type of vitamin D that the body naturally produces through sunlight exposure and utilizes most effectively to boost overall vitamin D levels.
Researchers examined data from controlled trials and found that taking vitamin D2 led to a reduction in vitamin D3 levels.
Author's summary: Vitamin D2 supplements may lower vitamin D3 levels.