The Dutchman has a case of suspected food poisoning and was forced to withdraw before the sixth stage of the race in Malaysia.
He had already won two stages and wore the yellow jersey for two days last week.
"Yeah, it is s**t. I have to stop, I'm going home," he told Cycling News.
"Maybe it's from too much hand shaking, that's also not a very good thing to do."
The race continues without Bos on the 212.8km route to Kuantan.