Vitamin D3 is needed by the body to maintain proper function of the muscles and the immune system, as well as maintaining healthy bones and teeth.
Vitamin D is known as the sunshine vitamin, as it's something you get when your skin is exposed to sunlight. When you're not exposed to sunlight, your body doesn't produce it, which is why a Vitamin D3 supplement is ideal.
Vitamin D3 is formed using ultraviolet B rays from the sun (UVB), and is thought to be three times as potent as Vitamin D2.