A new study from the University of Surrey, in collaboration with the John Innes Centre and Quadram Institute Bioscience, has raised concerns about vitamin D2 supplements.

Researchers found that taking vitamin D2, a common form of the supplement derived from plants, can actually lower the body's levels of vitamin D3, which is the form naturally produced through sunlight exposure and considered more effective for raising overall vitamin D status.

The meta-analysis of randomized controlled trials, published in Nutrition Reviews, showed consistent drops in vitamin D3 concentrations among participants using D2 supplements compared to control groups.

Vitamin D is crucial for bone health, immune function, and overall wellness, particularly in regions like the UK where winter sunlight is insufficient for natural production.The UK government recommends 10 micrograms daily, especially from October to March.

Lead researcher Emily Brown emphasized that while supplements are important during low-sunlight periods, D2 may not be the optimal choice for everyone.

The study also references prior research indicating that vitamin D3 uniquely supports the type I interferon signaling system, providing a stronger first line of defense against viruses and bacteria.Experts suggest prioritizing vitamin D3 supplements or ensuring better access to plant-based D3 sources.

This finding could influence future public health guidelines on vitamin D fortification and supplementation strategies to better combat widespread deficiency.

Professors involved highlighted the need for more research into the distinct roles of D2 and D3 in immune health and called for innovations in food to improve nutrient density.

Overall, the research encourages individuals to consider personal needs when choosing supplements but points toward D3 as potentially superior for most people.