
"Unfortunately, my decision to have Phil deliver the Macworld keynote set off another flurry of rumours about my health, with some even publishing stories of me on my deathbed," Jobs said.
The rumours caused Apple shares to shrink at the end of 2008 as investors worried about his health and the future of the company.
"The remedy for this nutritional problem is relatively simple and straightforward, and I've already begun treatment," Jobs declared in the letter.
"But, just like I didn't lose this much weight and body mass in a week or a month, my doctors expect it will take me until late this Spring to regain it. I will continue as Apple's CEO during my recovery."