When it comes to vitamin D, there’s more to the story than meets the eye. Many folks may not be aware that vitamin D comes in two distinct forms: vitamin D2 and vitamin D3. While vitamin D3 has long been hailed as the more potent and beneficial option, there’s a twist in the tale, especially for those following vegan or vegetarian diets. In this article, we’ll explore the importance of vitamin D for immune health and why vitamin D3 might be the smarter choice.

The Vegan Dilemma

For vegans and vegetarians, vitamin D2 has been the go-to choice as it is sourced from non-animal origins. However, when it comes to bolstering the body’s defences, the evidence suggests that vitamin D3 takes the lead.

New Insights from a Study

In the February 2022 issue of the journal *Frontiers in Immunology*, a study shed light on this vitamin D debate. Researchers conducted a 12-week study involving a substantial group of healthy European and South Asian women during the winter months. They administered either vitamin D2 or vitamin D3 and made a remarkable discovery: vitamin D3 enhanced the secretion of interferon from immune cells, a vital component in the body’s defence system against infections, including COVID-19 and cancer. Interferon plays a multifaceted role, from alerting the immune system to recognizing and attacking invaders to preventing the growth of viruses and cancer cells.

The Power of Interferon

Interferon, as a vigilant immune system messenger, accomplishes several essential tasks:

• Alerts the immune system to take action against viruses and cancer cells.
• Aids in the recognition of these threats by the immune system.
• Coordinates the efforts of other immune cells to combat the invaders.
• Halts the replication and growth of viruses and cancer cells.
• Assists healthy cells in their fight against infections.

Regarding COVID-19, the researchers noted that “our finding that vitamin D3 appears to stimulate type I interferon signalling could be relevant in the context of its use as a prophylactic treatment” to help prevent severe COVID-19 complications.

The Source Matters

It’s worth noting that vitamin D3, found in supplements and many fortified dairy products, shares its origin with our own skin’s vitamin D synthesis when exposed to sunlight—sheep’s skin (lanolin). In contrast, vitamin D2, present in select supplements and fortified foods like some orange juices and cereals, is produced by exposing various mushrooms to UV light. Vitamin D2, also known as ergocalciferol, is less costly, which is why some products opt for it instead of vitamin D3.

The Preferred Choice

Considering the growing body of evidence, opting for supplements containing vitamin D3 appears to be a wise choice. Not only does it have a positive impact on immune health, but it may also offer benefits for bone health. For those seeking robust support for their overall well-being, vitamin D3 stands out as the superior option.

Reference:

1. Louise R. Durrant, Giselda Bucca, Andrew Hesketh, Carla Möller-Levet, Laura Tripkovic, Huihai Wu, Kathryn H. Hart, John C. Mathers, Ruan M. Elliott, Susan A. Lanham-New, Colin P. Smith. *Vitamins D2 and D3 Have Overlapping But Different Effects on the Human Immune System Revealed Through Analysis of the Blood Transcriptome.* Frontiers in Immunology, 2022. [Read more](https://www.frontiersin.org/articles/10.3389/fimmu.2022.790444/full)
2. Science Daily: *Study questioning the role of vitamin D2 in human health but its sibling, vitamin D3, could be important for fighting infections.* February 25, 2022. [Read more](https://www.sciencedaily.com/releases/2022/02/220225085906.htm)

Dr. Meschino