Winter is looming, which means there's a potential for unwelcome ailments, from coughs and sneezes to full-blown flu.
A host of celebrities - - give their tips on boosting health and keeping winter bugs at bay.
"It's natural for your immune system to be under pressure in the winter, but rather than taking supplements, I try to keep my body healthy by eating good food.
"I love making things such as soups, which are so warming and satisfying in cold weather," says mother-of-one Air, 33.
"I believe you can cure lots of things in the kitchen, I think I was a witch in a past life, and so if I feel cold symptoms coming on, I'll make up a herby chicken stew or another of my favourites, a spinach and watercress soup.
"I also make a carrot, orange and ginger juice, which really boosts energy. You can cure so much with diet and juicing."
During the colder months, she eats foods rich in vitamin C, such as peppers, broccoli, sweet potato and oranges.
"I will occasionally take a vitamin C supplement as well, and if I'm having a stressful time, I will take a magnesium supplement as it can help relax tense muscles.
"I try to listen to my body and treat it well so that it stays healthy."
"There's nothing to beat a hot drink with a generous tablespoonful of manuka honey, which has natural antibiotic properties, and lemon juice," says Pendleton, the two-time Olympic gold medallist and world champion track cyclist, who's currently competing in BBC One's Strictly Come Dancing.
"I take that at the first sign of a sniffle or a sore throat and keep drinking it regularly until I feel OK."
She also takes fish oil supplements, a source of essential omega-3 fatty acids, which are valuable for supporting cardiovascular, circulatory and joint health.
"I also swear that by regular hand-washing and using an antiseptic hand gel you can cut down the risk of picking up cold and flu germs by around 50%."
"I'm a great believer in olive leaf extract, which was recommended to me by a naturopath and is known for its anti-ageing, immunostimulator and antibiotic agents," says TV presenter Roslin.
"During the winter I always start the day with porridge, which gives you slow-release energy and warms you from the inside."
"I use a B-complex supplement to give me an instant energy boost if I'm flagging.
"I rely on them if I'm really stressed," says mother-of-two Daly, co-presenter on BBC One's Strictly Come Dancing.
"Digestive health is so important. If that's working well, it means you're getting all the nutrients and necessary vitamins you need from food to keep you healthy," says Girls Aloud's Harding.
"I use activated charcoal and sprinkle it on my food. It doesn't taste of anything and apparently absorbs all the bad, damaging stuff in the body. I think it's good for hangovers, too."
Finding time to regularly relax, she believes, is key to re-energising and ensuring a healthy immune system all year round.
"The one place I can really unwind is in the bath, once I've put my son, Damian, to bed.
"I light a candle, sprinkle in some Dead Sea salts and Jo Malone bath oil, and then read for half an hour.
"It also helps me sleep and rest properly, which is essential so the body can re-charge."
She never eats processed food, avoids all alcohol apart from vodka, and says: "I'm convinced that eating processed food encourages weight gain, so I like food in its simplest state."
"I have a recurring problem with dry, irritated skin," says mother-of-two Lloyd.
"It can be more of a problem in winter, so I keep an ITCHeze spray in the fridge which helps soothe and calm it down. It also helps when I get a blotchy rash on my chest that flares up if I'm stressed or nervous."
" Comvita UMF Manuka Honey has antibacterial and antiviral properties, so it's great for fighting colds," says actress and TV presenter Faulkner, the winner of BBC One's Celebrity MasterChef.
"Look out for the UMF (unique manuka factor) on the pot - the higher it is, the more potent the honey."
"I was really shocked when a doctor told me a blood test showed a lack of vitamin D," says Tointon, ex-EastEnders actress and former winner of Strictly Come Dancing.
It's well known that vitamin D levels can drop during the winter because of the lack of sunshine. Direct sun on our skin is one of the chief ways in which we absorb it.
"It happened last winter as I'd been starring in a stage play and working in a film studio with no access to natural light. My doctor said I needed to take vitamin D supplements, so I went to Holland & Barrett and got the BetterYou Vitamin D Spray.
"All I had to do was spray it into my mouth once a day.
"That way the vitamin D was absorbed quickly into my bloodstream. I've carried on taking vitamin D supplements, so hopefully that will stop it happening again."