“How do I boost my immunity?” It’s a question that gets asked all the time, but especially during flu season and colder months when everyone you know seems to be coming down with something.

A vigorous immune system readily fights off pathogens and invaders, but if we are run down by nutrient poor diets, stress overload, or lack of quality sleep, our chances of getting sick increase. Luckily, there are simple, daily lifestyle adjustments you can make to support your immune system and optimize its ability to battle infection.

1. Increase the whole foods and plants in your diet. Vitamins A, C, E, and D, minerals zinc and selenium, and omega-3 fatty acids are vital to a functioning immune system. Whenever possible, choose whole, natural foods. High quality proteins, a wide array of fruits and vegetables, whole grains, raw nuts and seeds are all good options. Stay hydrated with plenty of pure water. Avoid soft drinks, processed foods, fried foods, artificial sweeteners, trans fats, fast food, and refined starches and sugars. For an added immune boost, you can supplement with astragalus, reishi mushroom, bee pollen, and spirulina and microalgae.

2. Eat organic. Poor quality diets leave us nutrient-depleted and are a cause of weakened immune response. Fresh fruits and vegetables contain numerous vitamins, minerals, and phytochemicals that are essential for vibrant health. Citrus fruits, dark leafy greens, berries, broccoli, tomatoes, papaya, and red peppers are among the many fruits and veggies loaded with vitamin C: a major immunity booster. Purchasing organic products as often as possible reduces your exposure to carcinogenic pesticides. If you’re shopping on a budget, check out the Dirty Dozen and Clean 15, which lists the produce items most (and least) contaminated with pesticide residues.

3. Manage your stress levels. Did you know that prolonged stress can lower the body’s disease-fighting white blood cell count? While some stress is normal and can even motivate us, excessive or chronic stress can be exhausting, leaving us run down and vulnerable to infection and illness. Learning to manage stress well is a key component of healthy immunity. Meditate, spend time with loved ones and pets, exercise, do yoga, and focus as much as you can on the things that bring you happiness. A therapist (or a trusted friend) call also serve as a good sounding board.

4. Emphasize probiotics for a healthy gut. A healthy GI tract is key to a strong immunity. Probiotics are essential to maintaining great gut health. Balanced intestinal flora contribute to better nutrient absorption, and help keep the intestinal lining strong, forming a barrier against pathogenic microbes and other harmful substances. Probiotics help alleviate inflammation in the gut, which also supports healthy immunity and digestion. Eat probiotic-rich foods, such as kimchi and sauerkraut, and take a high quality probiotic supplement every day.

5. Commit to exercise you enjoy. Getting moderate to vigorous exercise every day is one of the most important things we can do for our health. The key is to avoid overtraining, which can add to your body’s stress levels. It’s vital to exercise in ways you genuinely like. You don’t want exercise to be one more chore you dread doing. Yoga can be excellent exercise for immunity. It promotes relaxation and a healthy stress response, helps lower stress hormones that negatively impact the immune system, and stimulates the lymphatic system to give toxins the boot.

6. Prioritize sleep. Getting enough sleep is integral to good immune function. Aim for seven to nine hours of uninterrupted sleep a night, so your body can fully rest, repair, and charge up for the coming day. Practice good sleep hygiene habits. Take an hour (at least) to wind down before bed. Play soothing music or read a good book. Sip on some herbal tea, like chamomile, peppermint, or passion flower, which have relaxation-promoting compounds. Invest in cozy sheets, pillows, and blankets, and use a sleep mask, or blackout curtains, so that you sleep in complete darkness. You want your bedroom to be a comforting, restful retreat; keep devices, televisions, and computers in other parts of the house. Quality sleep will supercharge your immunity.