How can i make my skin naturally glowy?

My skin tone is medium. I just want to know how I can make my natural brown skin have that sort of sun kissed natural glow that it used to have. Right now my complexion is very dull. I know there are vitamins that can help with this, I just don't know which ones. If anyone can help me out that would be great ! Also anything else that would help other than vitamins would be appreciated as well !