Taking a lot of vitamin D might help your muscles grow bigger by turning down a natural brake that stops them from growing.

Taking vitamin D might help your body release a hormone that tells you when you're full and also stop a protein that blocks muscle growth, so you could feel more energized and build muscle more easily.

If you make muscle cells produce more of a protein called the vitamin D receptor, the muscles get bigger because they start making more protein, grow more repair cells, and stop a protein that normally limits muscle growth.

When scientists turned up the vitamin D receptor in the leg muscles of rats for 10 days, the muscle fibers got bigger, the muscles made more protein, and key growth signals kicked in—so it looks like boosting this receptor might help muscles grow.

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.

When mice don’t get enough vitamin D from their diet, their muscles start breaking down more because certain proteins that signal muscle loss become more active.