Apple co-founder Steve Jobs is leaving the company until the end of June for medical reasons.

Jobs earlier this month said he would remain at work but undergo “relatively simple and straightforward” treatment for an unspecified hormone imbalance that led to his recent dramatic weight loss.

Now, “unfortunately, the curiosity over my personal health continues to be a distraction not only for me and my family, but everyone else at Apple as well. In addition, during the past week I have learned that my health-related issues are more complex than I originally thought,” Jobs said in a letter posted on Apple.com yesterday.

Jobs will “remain involved in major strategic decisions while I am out,” he said, with COO Tim Cook serving as interim CEO.

The charismatic and often enigmatic Jobs fought a rare form of pancreatic cancer in 2004.

Apple’s other co-founder, Steve Wozniak, survived an airplane crash in 1981 and suffered from temporary amnesia.