Vitamin D is a fat-soluble vitamin that the body needs to regulate cell growth, combat inflammation, and enhance immune function. Vitamin works with calcium to maintain strong, healthy bones and help prevent osteoporosis. Good sources of vitamin D include fatty fish like salmon, mackerel, and tuna. Smaller amounts are found in egg yolks. Fortified milk and orange juice may contain vitamin D as well. The best way to get vitamin D is to spend approximately 10-15 minutes outside in the sun on a clear day without sunscreen. Your skin manufactures vitamin D when you get sun exposure. Be careful not to burn! Excess sun exposure and sun burns increase the risk of skin cancer.