Oct 5, 2008, 11:00 GMT
Sharon Osbourne was furious when her daughter Kelly began using the contraceptive pill.
09/05/2008 - Sharon Osbourne - Stand Up To Cancer - Arrivals - Kodak Theater - Hollywood, CA. USA © Albert L. Ortega / PR Photos
Sharon - the wife of rocker Ozzy Osbourne - is convinced the medication caused her colon cancer and was terrified Kelly would also fall victim to the life-threatening disease.
Kelly, who is an ambassador for World Contraception Day, said: "Mum did have a problem with me going on the pill. She doesn't like that I am on it. Because of her history she is absolutely convinced it causes cancer."
Sharon was diagnosed with colon cancer in 2002.
After successfully undergoing treatment, she established The Sharon Osbourne Colon Cancer Program at Los Angeles' Cedars Sinai Medical Center.
Kelly has also revealed her parents first spoke to her about sex when she was just seven.
The 23-year-old TV presenter said: "At every single one of my dad's shows, they hand out free condoms. I picked one up when I was about seven and asked, 'Mum, what is this?' She had to explain it to me.
"It's something my parents have never been shy about. They want me to protect myself."
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