Fifty-five-year-old music mogul Simon Cowell has regular vitamin injections to stay as healthy as possible because he can't bear the thought of being out of action.

His close friend Sinitta said: "Simon loves having vitamin injections because his life is so non-stop and he is phobic about getting sick or catching a cold. "He has them regularly and just the other week had one in his 'X Factor' dressing room."

Sinitta - who raises adopted children Magdalena, nine, and Zac, eight - says Simon has changed a lot since his girlfriend, Lauren Silverman, gave birth to their first child, Eric, in February and predicts they will have more children.

She told Closer magazine: "Baby Eric is a mini Simon and so adorable. He's crawling and moving around so much. Becoming a father has been the making of Simon, it's changed him. I think he and Lauren will definitely have more kids. They're both great parents."

However, the So Macho hitmaker isn't convinced the couple will ever get married.