Despite its name, vitamin D is not technically a vitamin. Vitamins are nutrients that people can only obtain through diet. But the body produces vitamin D from exposure to sunlight, so it is actually classed as a prohormone. Without vitamin D, the body cannot absorb calcium. Not only does the body use these minerals to strengthen the bones and teeth, they are also necessary for the muscles to function properly, including the heart. It also supports the immune system and it may be a help weight loss aid.
However, the reason there are so many concerns about vitamin D deficiency is because it can be hard to get enough. There are very few food sources that contain vitamin D. Oily fish, cheese, egg yolks and beef contain some, but the best way to get it is from the sun. But it can be difficult to get enough UV exposure safely without damaging the skin. Sun damage can cause sunspots and even increase the risk of skin cancer.
