Back to today’s briefing

Story perspectives

Study Reveals D3 Outperforms D2 for Immunity Boost

9/30/2025

47 6

Summary

Story summary

A University of Surrey study finds vitamin D2 lowers vitamin D3, implying D3 is more effective.
Vitamin D supports bone strength and immunity, especially in UK winter.
Emily Brown of the University of Surrey led an analysis of randomized trials.
Brown notes the D2–D3 effect remains unknown.
Smith notes that D3 stimulates the immune system's first line of defense.

1 of 1

Story summary

A University of Surrey study finds vitamin D2 lowers vitamin D3, implying D3 is more effective.
Vitamin D supports bone strength and immunity, especially in UK winter.
Emily Brown of the University of Surrey led an analysis of randomized trials.
Brown notes the D2–D3 effect remains unknown.
Smith notes that D3 stimulates the immune system's first line of defense.