Vitamin C: Vitamin C may help to prevent infections, including those caused by bacteria and viruses. Regularly administered vitamin C has been shown to shorten the duration of colds, and higher doses of vitamin C during an illness can also act as a natural antihistamine and anti-inflammatory.
Vitamin D: Vitamin D, known as the “sunshine vitamin,” is one of the most important and powerful nutrients for supporting the immune system. Numerous studies have shown that it helps reduce the risk of colds and flu. Unfortunately, a high percentage of the population is deficient, so daily supplementation (ideally in the form of vitamin D3) offers the best protection.
Vitamin A: For short-term use and particularly for those with moderate vitamin A deficiency, supplementation can be extremely helpful in supporting the body’s ability to fight infections, particularly with regard to respiratory infections.
Zinc: Zinc plays a significant role in boosting immunity. Often available as lozenges, zinc can help to reduce the frequency of infections as well as the duration and severity of the common cold when taken within 24 hours of onset.
Selenium: Selenium, a key nutrient for immune function, is also an antioxidant that helps boosts the body’s defenses against bacteria, viruses, and cancer cells. It may particularly help to protect against certain strains of flu virus. Selenium is easily obtained from foods, with the richest source being Brazil nuts.
Honey: Honey, preferably raw, is a good demulcent (it relieves minor pain and inflammation of mucous membranes), has antioxidant properties, and has some antimicrobial effects. It is helpful for coughs and sore throats and can be added to hot tea.
Garlic: Garlic contains a variety of compounds that can influence immunity. Some studies have shown that both fresh garlic as well as aged garlic extract and some other garlic supplements may reduce viral upper respiratory infection severity as well as function in the prevention of infection with viruses that can cause colds.
Probiotics: Probiotics contain “good bacteria” that not only support the health of the gut but also influence immune system functioning and regulation. Studies have shown that probiotic use can decrease the number of respiratory infections, particularly in children.
Stress reduction: Chronic stress can negatively alter immune system responses, making you more likely to get sick. Identify your personal stress reduction strategies and practice them regularly.
Sleep: Sleep has a big influence on immune function, so it is essential to get plenty of sleep. Practice good sleep hygiene and maintain consistent sleep hours—turn off screens, ensure the room is cool, quiet, and dark, and set a reminder to help yourself go to bed on time.
Exercise: Moderate, regular physical activity helps to boost immune system function by raising levels of infection-fighting white blood cells and antibodies, increasing circulation, and decreasing stress hormones. Establish and follow an exercise program to not only help prevent respiratory infections but also to improve cognitive and physical resilience.
Nutritious foods/diet: Research indicates that brightly colored vegetables and fruits boost immunity better than most supplements. Eat plenty of fruits and vegetables—aim for 10 servings per day. Include fermented vegetables or other probiotic-containing foods.