Scientists Warn That Vitamin D2 Supplements May Reduce Levels of Vitamin D3

Vitamin D supplements are widely used to prevent or correct vitamin-D deficiency, but new research suggests that different forms of the vitamin may not behave identically in the body.

Scientists investigating vitamin D2 and vitamin D3 found evidence that supplementation with vitamin D2 can lower levels of vitamin D3, the form naturally produced by the body following exposure to sunlight.

The finding is important because vitamin D plays roles in bone health, calcium metabolism and several other physiological processes. People often treat vitamin D supplements as interchangeable without considering the differences between formulations.

The research does not mean that vitamin D2 is inherently dangerous or that people taking supplements should stop them. The clinical importance of the interaction requires further investigation, particularly because vitamin-D status is influenced by diet, sunlight exposure, body composition, health conditions and supplementation.

The findings reinforce the importance of avoiding excessive self-supplementation and using medical testing and professional guidance when treating confirmed vitamin-D deficiency.