Like calcium, it keeps your bones strong and helps your nerves carry messages. It also plays a role in fighting germs. Careful time in the sun — 10 to 15 minutes on a clear day, without sunscreen — is the best source. Or you could eat fish such as salmon, tuna, and mackerel. There’s a little in egg yolks, too. You can also get milk and sometimes orange juice with added vitamin D.
