Myth or truth?
Loading up on vitamin C can ward off colds.
Answer: Myth. Dozens of studies have disproved this old saw for ordinary folks, although for some people in extreme conditions, like marathoners, taking 1,000 mg vitamin C regularly during cold season may slightly shorten colds.

Myth or truth?
You can catch a cold through your eyes.
Answer: Truth. Your eyes are connected to the nasal membranes by the tear ducts, allowing viruses to sneak in through your peepers. Rhinoviruses can live up to three hours on surfaces or on your skin – so hands off! Wash hands seven times a day or more – throughout the day – and you’ll cut your risk of respiratory illnesses in half, research shows. As effective alternatives, the Centers for Disease Control and Prevention, or CDC, recommends alcohol-based hand sanitizers or wipes. 

Myth or truth?
Flu shots are not safe if you have RA.
Answer: Myth. "People with autoimmune diseases are often afraid the flu vaccine will give them the flu or won't help," Dr. Jain says. "But it's safe and effective."

In fact, the CDC recommends an annual influenza vaccine for everyone with an autoimmune disease, unless they have an egg allergy (because the vaccine is made using eggs) or a history of serious side effects.

Those who take certain medications, like prednisone, may receive less protection, but it's still safer than going without, Dr. Jain says.

The flu shot won't give you the flu because it contains inactive virus. But people with autoimmune forms of arthritis or otherwise have compromised immune systems should avoid the nasal-spray version, which contains live virus.

What happens if you do get sick? For both the flu and colds, your best bet is to drop everything and rest, drink lots of fluids and tell your doctor. "Since your immunity is compromised already, it's smart to be more cautious and get health care early," says Dr. Jain. Your doctor may decide you need to back off certain medications, she says.

You may also want to take Tamiflu, a drug that eases flu symptoms; it’s safe for people with RA. But it must be started within two days of infection.