Mia Farrow has stopped her fast in solidarity for the people of Darfur due to "serious health concerns" her doctor raised, the actress told FOXNews.com in a statement Friday.

“I have been instructed by my doctor to stop my fast immediately due to health concerns – including possible seizures. I am fortunate. The women, children and men I am fasting for do not have this option,” Farrow said.

Billionaire mogul Richard Branson will take over for Farrow, who has not eaten in 12 days.

According to Farrow, her health has taken a downturn over the last few days and her doctor has ordered her to stop immediately.

"I am honored to be taking over the fast for the next three days from Mia Farrow in her courageous stance to support the people of Darfur," Branson said.

The 64-year-old Farrow – who weighs just 110 pounds — says she began the fast “as a personal expression of outrage at a world that is somehow able to stand by and watch innocent men, women and children needlessly die of starvation, thirst and disease.”

She told FOXNews.com that the idea to undertake the fast came about from “absolute outrage,” when humanitarian aid agencies were expelled from Sudan after President Omar al Bashir was issued an “arrest warrant for the murder, rape, torture and displacement of millions.”

“I didn’t know what else to do, the desperation of the situation,” she said. “I thought if I go on a hunger strike this is a time-honored way of drawing focus to the issue and shame to the perpetrators, I realize it is an extreme thing to do but worse things are happening to the people of Darfur. I felt compelled, I cannot just watch.”

The “Rosemary’s Baby” star and U.N goodwill ambassador has visited the war-torn region 11 times over the past five years.

The United Nations says up to 300,000 people have died in Darfur, where ethnic African rebel groups have been fighting the Arab-dominated national government for six years.

The decision to have Branson continue the efforts was part of Farrow’s original plan.

“When I began this fast 12 days ago, I hoped another would take my place, and another, and another, until the expelled humanitarian agencies are re-admitted and finally there can be justice and peace for the people of Darfur. … Richard Branson has stepped forward and so I have ended this fast.”