"I feel cheated sometimes," Vieira, 56, admits in the November issue of Ladies' Home Journal. "We used to run together and go on ski trips or go to the beach. Now it's very hard for Richard to stand. But we're very lucky in what we do have."
Sixty-two-year-old Cohen, an Emmy-winning TV producer whose father also had MS, was diagnosed with the disease in his 20s and revealed his condition to Vieira on their second date.
The couple went on to wed in 1986 and raise three children -- Ben, 21, Gabe, 19, and Lily, 17 -- but Vieira admits the marriage has had its problems from time to time.
"We've had plenty of those, partly because of health issues, which put a strain on the relationship," Vieira says of Cohen, who also battled colon cancer twice.
"And we're both stubborn people -- we can lock horns easily. But a sense of humor helps. If something were to happen to Richard, I would never get married again. It's hard work to be married. I've been married once -- that's the guy."
Not surprisingly, Vieira's family life and super-early work schedule can leave her a little worn out, and the NBC star claims her colleagues believe she could benefit from Botox.
"They've probably thought it, but nobody has said it," Viera, who wears a bright blue sheath with cutout sleeves for the issue's cover and accompanying profile, tells the magazine.
"When I came back from vacation, some people said, 'Did you have work done?' They looked so relieved. I told them, 'No, I slept.'"
Vieira, who has resisted plastic surgery, also tells Ladies' Home Journal that the "Today" schedule left her so run down last year that she began to pack on the pounds.
"This is a high-energy show, and I can pull it off, but I was really feeling it. I was gaining weight and feeling depressed," says Vieira, who met with a nutritionist and was put on a 28-day detox diet that cut out sugar, wheat, gluten, alcohol, and caffeine.
Besides changing her eating habits, Vieira also began working out with heavy weights to burn calories and build muscle. Now 10 pounds lighter, Vieira maintains her figure by sticking mostly to fish and salads.
"I want to look healthy, be strong, and feel good about myself," says Vieira, who also boosts her confidence and her height with her impressive collection of stilettos. "I'm really short, 5 foot 3 1/2, and from the time I could wear heels I did," she explains. "I wanted stature."
Despite feeling comfortable in her skin, there is one thing Vieira wishes she could change about her appearance: She just wants to go gray. Though she began to let her true colors shine through while she was still moderator of "The View," that all changed in 2002 when she got a gig as host of the game show "Who Wants to Be a Millionaire?"
"[They] said we don't want you coming in with gray hair, we want you to look polished and color your hair," she says. "And I did it. I want to think that if I weren't doing these two jobs I'd let it grow out, because it's a pain in the neck."
As for whether she'll exit the "Today" show when her contract ends next year, Vieira says, "I'll know when it's time to go, and I'm not afraid to go. If I were to leave at the end of next year because it's time for me, I wouldn't jump into another show. I would look forward to not working, to traveling with Richard and carving out time for us."
In other news, read what Joan Collins has to say about cosmetic surgery, Angelina Jolie, and Jennifer Aniston.