This particular vitamin acts more like a hormone in the body, as is essential for... a bazillion functions in the body.
A good chunk of the world, especially in Northern or Southern latitudes that experience seasons. Or, in areas where people don't get outside, into the sun, regardless of the season.
Yes, Vitamin D.
But, did you know it's also essential for the bugs in your gut???
Having adequate amounts of Vitamin D equated to an overall modulatory effect on your own microbiome. Both in species richness, and overall composition.
This is an extremely important factor when considering the health of your microbiome is essential for nearly every aspect of your overall health (Which, goes for Vitamin D as well). Every system of your body is affected by the health and diversity of your biome.
Particularly your gut, immune system, and brain and nervous system.
What researchers found in a study done in Italy in 2021 was that Vitamin D played an important role in modulating the diversity and species richness.
This is a factor that has not received a lot of attention, but supports an ever more important reason to optimize vitamin D levels. The best way is to get plenty of sun exposure. Next, plenty of bioavailable vitamin D from high quality food sources. Lastly, proper supplementation, and I mean proper.
More on vitamin D in other articles.