In people who are overweight or obese, having more vitamin D in their body seems to be linked to how many calories they burn at rest, and this link happens because of how their body uses the vitamin D receptor gene — but not because of the PGC-1α gene.

If you have more vitamin D in your body, your body burns more calories while you're just sitting still—even if you don’t move more or eat differently.

Having more vitamin D in your body might help you build more muscle and store less fat, directing your body’s energy toward making lean tissue instead.

People who naturally have more vitamin D in their blood tend to grow taller as they develop, which might mean their bodies are more focused on building muscle and bone rather than storing fat.

In Australians with European roots, having more vitamin D in your blood might help you burn more calories while at rest—but if your body is better at using insulin, that calorie-burning boost might not be as strong.

Men who had excess belly fat saw their vitamin D levels go up by 27% after a year of eating better and moving more—even though they didn’t take any vitamin D pills or supplements.