His family and political party have reportedly urged him to forgo the protest -- not only out of concern for his personal well-being, but also because they believe hunger strikes have lost their power as a political tool.
The West had critical words to say when Kazulin, the former rector of Belarus State University and head of the Hramada party, was sentenced in July to 5 and 1/2 years in jail for his role in a peaceful opposition march.
Now, says his wife Iryna, Kazulin is hoping the West will once again come to his defense.
"As far as I understood, he primarily wants international organizations to speak out [on Belarus]. I asked him straightforwardly: 'When will you decide to end your hunger strike?' He answered that [he will do this] when the Belarus issue is put on the agenda of the United Nations," Kazulina said.
Hunger strikes are seen throughout the world as a protest of last resort and a powerful form of moral pressure.
They have been used by everyone from Indian spiritual leader Mahatma Gandhi to prisoners at the U.S. military prison at Guantanamo Bay, Cuba.
Denis O'Hearn, a sociologist and biographer of perhaps the world's best-known hunger striker, Irish republican Bobby Sands, says it's the ultimate form of protest.
"It takes a very long time, it's a very painful way for someone to die. And if people are willing to go through that, either to the death or nearly to the death, it's quite an extreme and wrenching form of protest," O'Hearn says.
Sands was the first of 10 Irish republicans who systematically starved themselves to death in a British jail to protest prison conditions.
He died in May 1981, after 65 days in which he ingested nothing but water and occasional spoonfuls of salt to give his body the minimum it needed to stay alive.
Hernan Reyes, who oversees prisoner medical issues for the International Committee of the Red Cross, says determined strikers want to stay alive as long as they can.
The longer they fast, the rationale goes, the more extreme their suffering -- and the more powerful their message. It only takes a few weeks for the physical pain of a fast to become profound.
"You don't feel hunger after a few days because of the ketosis. You have ketones in your bloodstream, which actually stamp out sensations of hunger as we understand it," Reyes says. "But of course there are other sensations. After a couple of weeks you'll have what we call nystagmus, which means that you have these uncontrolled rapid eye movements which give you a feeling of dizziness or vertigo, and you feel like you just go off a carousel that's been spinning around very fast. And it's extremely unpleasant. People throw up, they can no longer drink their water. And this is definitely one phase of the hunger strike which all hunger strikers who reach it do remember."
That phase is rapidly approaching for the more than 150 Protestant believers in Belarus.
They launched a hunger strike on October 5 to protest the ejection of their community called the New Life Church from property it legitimately purchased from the state in 2002.
Azerbaijani students hunger strike against nonrecognition of their university diplomas
The New Life community says authoritarian President Alyaksandr Lukashenka and other officials have been relentless in their repression of religious minorities in Belarus.
Now 14 days into the fast, they have vowed to see the strike through to the end if their demands are not met.
New Life member Uladzimir Mackevich says the group remains determined.
"[Our] mood is good, elated. We are convinced that we will win. It is a serious, composed mood. The initial enthusiasm has ended, and now we are soberly confident," Mackevich said.
The mass protest may be getting results. New Life on October 18 filed an appeal with Belarus's Supreme Economic Court against the city decision to confiscate the church's land.
The group filed the appeal at the recommendation of Lukashenka's aide for ideology. The president, in a sudden show of sympathy, had ordered that the church be helped.
Reyes says the success of a hunger fast -- among both prisoners and regular protesters -- largely depends on how willing a government is to stand by as a person or a group slowly and painfully starves itself:
"To protest by fasting is for prisoners very often the last resort they have to make their protest known outside. Of course, this implies that they can make it known outside, which is not always the case in many countries. [It also implies] that the country actually cares about their image -- not the prisoner's image, but their own image as authorities, as being benevolent and listening to this last resort of this prisoner calling for some specific action," Reyes says.
Lukashenka is not usually credited with having a benevolent side. But a third hunger strike has also gained the attention of the authorities.
Independent trade unionist Alena Zakhozhaya has been fasting since October 3.
She is protesting what she says is discrimination against fellow union members by a regional tire factory that is part of Belnaftakhim, the state petrochemical concern.
Her campaign appeared to score a victory earlier this week, when Belnaftakhim representatives promised to deliver unpaid bonuses and restore other benefits promised under the terms of the union's collective bargaining agreement.
But until the money had arrived in the proper accounts, Zakhozhaya says she will continue her fast.
"A representative of the concern [told me]: 'Stop your hunger strike, give us 10 days and we will resolve this problem.' I said 'I can't, you'll trick me one more time.' Therefore, as long as I can hold my ground, I will hold it," Zakhozhaya says.
(RFE/RL's Belarus Service contributed to this report.)
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