Why is vitamin D is the sunshine vitamin?
Vitamin D is the sunshine vitamin because sunlight helps synthesize it. Sunlight converts a compound in the skin called cholecalciferol to a vitamin D precursor called vitamin D3. This compound then enters the bloodstream and travels to the liver and kidney for processing. After leaving the kidney, vitamin D is active and ready to use.
Vitamin D deficiency means you are deficient in vitamin D. Vitamin D is the sunshine vitamin which your body makes from being exposed to sunshine. You can get vitamin D from eating fatty fish like salmon and tuna or beef liver. Some dairy products are fortified with vitamin D and so are some breakfast cereals.