Vitamin D3 Bolsters Immune System Better Than Vitamin D2: Researchers

Vitamin D is an important component for bone and immune system health, but recent study reveals that not all versions of the vitamin are created equal.

Scientists from the Universities of Surrey and Brighton in the United Kingdom looked at two types of vitamin D supplements — those containing vitamin D2 and those containing vitamin D3 — and found that only vitamin D3 had an effect on the body that might help the immune system.

“We have shown that vitamin D3 appears to stimulate the type I interferon signaling system in the body — a key part of the immune system that provides a first line of defense against bacteria and viruses,” Colin Smith, PhD, a professor of functional genomics at Brighton and a lead study author, said in a press release. “Thus, a healthy vitamin D3 status may help prevent viruses and bacteria from gaining a foothold in the body.”

This is significant, because previous research indicated both forms of vitamin D were equally effective, while this latest study suggests foods fortified with vitamin D should prioritize D3 over D2.