Voters know a little bit more about Republican vice presidential nominee Sarah Palin’s health as they head to the polls today. According to a two-page letter released by her physician last night, Palin, 44, is in "excellent health and has no known health problems that would interfere with her ability to carry out the duties and obligations of vice president of the United States." 

Until now, Americans knew next to nothing about Palin’s health, other than that she gave birth to five children, the youngest of whom was born with Down Syndrome in April. (People with Down Syndrome have an extra copy of chromosome 21, and have mental and sometimes physical deficits, including heart abnormalities.) According to Palin's doctor, Cathy Baldwin-Johnson, the births were the only time the veep wannabe has been hospitalized.

Among other disclosures, reports the Associated Press: Palin had a breast biopsy in 1992 that turned out to be benign; her blood pressure was a normal 96 over 61 during her last check-up; she exercises regularly and she doesn't routinely take any medications.

The health of political candidates has been fair game since Ronald Reagan authorized his physicians to be interviewed by reporters who questioned his fitness given his age – 69 – during his 1980 White House run, the New York Times recently noted. But while Palin’s running mate, John McCain, released 1,200 pages of his medical records in May – including details about his four bouts of the potentially deadly skin cancer melanoma – and Democrats Barack Obama, 47, and Joe Biden, 65, shared some of their health battles, gaps remain in voters’ knowledge.

It’s still unknown whether McCain, 72, has undergone testing for memory deficits and how recently Biden, who nearly died of a brain aneurysm in 1988, received brain imaging scans. (An aneurysm is a bulge that forms in a blood vessel that can burst. Biden's leaked but didn't rupture.) A letter from Obama's doctor declared the Democratic presidential nominee to be in "excellent health," but didn't give any other details including whether he had been successful in his campaign to quit smoking.

(Updated at 4:35 p.m. to correct definition of aneurysm, clarify that Biden's aneurysm leaked, not burst.)

(Image of Sarah Palin/Tricia Ward)