Best Supplements for Respiratory Immunity (2026) – Top 10 Reviewed
Your respiratory system serves as the frontline of your immune defenses, constantly filtering air and defending against airborne pathogens. Supporting respiratory immunity becomes especially important during cold and flu season or when environmental challenges put extra stress on your lungs and airways. This guide explores the top supplements formulated to strengthen your respiratory defenses, helping you breathe easier while building robust immunity against respiratory threats.
Our Top Picks at a Glance
- Best Overall: NATURELO Vitamin D – plant-based immune support
- Best Value: Designs for Health Quercetin + Nettle – dual respiratory formula
- Best Premium: NATURELO Vitamin D3 K2 – synergistic vegan blend
Quick Comparison
| Product | Key Ingredients | Form | Servings | Best For |
|---|---|---|---|---|
| NATURELO Vitamin D | 5000 IU D3 from Lichen | Capsules | 90 | Immune regulation |
| Quercetin + Nettle | Quercetin, Nettle Leaf | Capsules | 90 | Respiratory support |
| NATURELO D3 K2 | D3, K2 MK-7 | Capsules | 60 | Synergistic formula |
| Beef Organ Supplement | 12-in-1 Organs | Capsules | 60 | Whole food nutrients |
| EZ Melts Vitamin C | Vitamin C 500mg | Melts | 60 | Fast absorption |
| Zinc A.G. | Zinc, Arginine, Glycine | Tablets | 90 | Enhanced absorption |
| Astaxanthin 10mg | Algae-Based Astaxanthin | Softgels | 60 | Antioxidant support |
| CoQ10 + PQQ Gummies | 400mg CoQ10, PQQ | Gummies | 60 | Cellular energy |
1. NATURELO Vitamin D – 5000 IU Plant-Based – Best Overall
- PLANT-BASED VITAMIN D3: Most vitamin D3 supplements are made from lanolin secreted from sheep skin. Our Vegan Vitamin D3 is sustainably sourced from wild-harvested lichen with no animal byproducts of any kind.
- HIGH POTENCY: 5000 IU of naturally bioactive Vitamin D3 can help restore blood levels in those who are deficient. Studies show that nearly half the U.S. population may be deficient in Vitamin D.*
- ESSENTIAL IMMUNE SUPPORT: Vitamin D is crucial for maintaining a healthy immune system.* Vitamin D levels may be especially low in winter or when you are stuck indoors.
- SUPPORTS BONE HEALTH: Vitamin D is necessary for your body to absorb calcium for strong bones and teeth. Risk of bone loss increases with age, particularly for women, and is also a risk during pregnancy.*
- CLEAN LABEL: Made in a GMP compliant facility. Non GMO, vegetarian, vegan, and gluten free. Does NOT contain soy, dairy, yeast, eggs, nuts, caffeine, preservatives, or coloring.
This plant-based vitamin D3 from lichen provides optimal immune support at 5000 IU per capsule, offering superior respiratory defense without animal-derived ingredients.
Vitamin D plays a crucial role in respiratory immunity by modulating both innate and adaptive immune responses in the lungs. This vegan-friendly formula delivers D3 (the more bioavailable form) derived from lichen rather than sheep’s wool, making it suitable for plant-based lifestyles. The 5000 IU dosage provides robust support for immune function, particularly important for maintaining healthy respiratory tract defenses. The 90-capsule bottle offers a full three-month supply of daily immune protection.
What We Like
- High 5000 IU potency supports strong immune response
- Plant-based D3 from lichen suitable for vegans
- Supports respiratory tract barrier function
- Three-month supply offers excellent value
What Could Be Better
- Higher dosage may be more than needed for some individuals
- May require monitoring vitamin D levels with long-term use
Bottom Line: For comprehensive respiratory immune support through vitamin D optimization, this plant-based high-potency formula delivers the immune-regulating benefits crucial for maintaining healthy respiratory defenses.
2. Designs for Health Quercetin + Nettle Supplement – Best Value
- Immune & Inflammatory Response Support - This formula delivers 600mg of Quercetin plus 600mg of Nettles in each serving. These two plant extracts have been shown to help the immune system, and the body's natural response to environmental challenges.*
- Why Quercetin? Quercetin has been called the king of flavonoids supplements, because of its powerful antioxidant properties. It helps the body regulate histamine.*
- Why Nettles? Nettle leaf has a high vitamin C content underlying its immune-supportive and antioxidant properties that may also benefit a normal inflammatory response.*
- Vegan & Non-GMO - These Nettle + Quercetin supplements are vegetarian and vegan-friendly. Made without GMOs, gluten, dairy, soy.*
- Over 50,000 Doctors Agree - Designs for Health is the physician's choice for top quality professional strength supplements since 1989. Our "Science First" philosophy ensures our Quercetin + Nettle supplement is based on the most recent research and use the highest quality raw ingredients.
This professional-grade formula combines quercetin’s antioxidant power with nettle leaf to support healthy respiratory function and seasonal comfort.
Quercetin is a powerful flavonoid antioxidant that helps stabilize mast cells and reduce histamine release, supporting comfortable breathing during seasonal challenges. Combined with nettle leaf extract, this formula provides comprehensive respiratory support through complementary mechanisms. Designs for Health is a practitioner-preferred brand known for research-backed formulations and high-quality sourcing. The 90-capsule bottle provides a full month’s supply at therapeutic dosing.
What We Like
- Quercetin supports healthy respiratory tract function
- Nettle leaf adds complementary respiratory benefits
- Professional-grade formula from trusted brand
- Research-backed ingredients at effective doses
What Could Be Better
- Requires multiple capsules per serving
- Professional-grade pricing reflects quality sourcing
Bottom Line: For those seeking a professional-grade respiratory support formula combining proven antioxidants with traditional botanical support, this quercetin-nettle combination delivers exceptional value and effectiveness.
3. NATURELO Vitamin D3 K2 – Vegan Formula – Best Premium
- BETTER TOGETHER: Vitamin D3 and K2 are perfect partners that work together to help your body absorb and use calcium properly, so that it goes into your bones -- and away from your arteries and soft tissues.*
- HEALTHY BONES & HEART: Vitamin D3 + K2 work together to support healthy bone density and healthy blood vessels for healthy circulation.* If you take calcium, adding D3 + K2 will support healthy calcium metabolism.*
- PLANT-BASED D3: Most Vitamin D3 supplements are made from lanolin secreted from sheep skin. Our vegan D-3 is completely plant-based and sustainably sourced from wild-harvested lichen.
- ACTIVE K2: Vitamin K2 as MK-7, a bioactive form of the vitamin that shows better bioavailability in humans and has well researched benefits for healthy bone building.*
- CLEAN LABEL: Made in a GMP compliant facility. Non GMO, vegetarian, vegan, and gluten free. Does NOT contain soy, dairy, yeast, eggs, nuts, caffeine, preservatives, or coloring.
This synergistic vegan formula pairs plant-based vitamin D3 with K2 MK-7 for enhanced immune support and optimal nutrient utilization.
The combination of vitamin D3 and K2 creates a powerful immune-supporting duo. While D3 regulates respiratory immune responses and supports lung tissue health, K2 ensures proper calcium utilization and may enhance D3’s immune benefits. The plant-based D3 from lichen makes this suitable for vegans, while the K2 MK-7 form (from natto) offers superior bioavailability. This thoughtful pairing addresses multiple aspects of respiratory and systemic immunity in one convenient capsule.
What We Like
- Synergistic D3 + K2 combination enhances effectiveness
- Plant-based formula suitable for vegan lifestyles
- K2 MK-7 offers superior bioavailability
- Supports both respiratory and cardiovascular health
What Could Be Better
- Premium ingredient combination reflects in price
- Contains both nutrients which some may prefer separately
Bottom Line: For premium vegan respiratory immune support with synergistic nutrient pairing, this D3 + K2 formula delivers comprehensive benefits for lung health and overall immunity.
4. 12-In-1 Beef Organ Supplement for Women
- Powerful 12-in-1 Work Synergistically for Overall Women's Wellness - 5X More Complete Than Single Beef Organ Supplement! Tired of juggling multiple supplements? Our beef organs capsules Deliver 5 Beef Organs + 5 Vitamins + 2 Herbs serving! Our powerful beef organ supplement for women is good for hormone balance, energy, menstruation, immunity, digestive, gut, detox & antioxidation, skin, mood & Zzz. Stop settling for one-dimensional beef liver capsules. Upgrade to total-body women's wellness!
- Specifically Designed For Women's Needs: Unlike basic beef liver capsules, we formulated with 12-in-1 powerful designed for women's needs. Complete Organ-Vitamin-Herb for Women Health, feel the Multi-Benefits with 5 grass-fed beef organs (1250mg), 5 vitamins and 2 herbs. 5 beef organs provide natural iron, CoQ10 & nutritional cofactors, 5 vitamin complex enhances bioavailability & effectiveness. Roselle & cranberry is good for antioxidant & urinary health. All-in-one give you the best results!
- Solution for Energy & Hormone Balance - Noticable results in 40 days! For women with irregular cycles and low vitality, our specialized formula of beef organ supplement with beef organs and multivitamins for natural hormone balance and against fatigue. Featuring natural heme iron from beef liver capsules alongside vitamin B12 and folate for daily energy. Our beef organ supplement for women for consistent vitality through your cycle. Say goodbye to hormonal chaos and hello to more energy
- Easy to Swallow, No Aftertaste & Odor - 120 Caps for 40-Day Supply, take 3 caps daily meet women's key nutrient needs for optimal results from our beef organ supplement for women. And our mini size beef liver supplement eliminate unpleasant taste & odors while preserving nutritional integrity from the beef organs, easy to swallow, store & take anywhere, making it easy to incorporate into your daily routine. Start with beef organ supplement to make women's wellness routine effortless & powerful
- 100% Grass-Fed, 3rd-Party Tested, 0 Compromises! We reject industrial farming. Our beef organ supplement for women is sourced from 100% grass fed, pasture-raised cattle without hormones antibiotics, fillers, or flow agents. Each batch of beef organ supplement is third party verified for purity and potency, ensuring freedom from heavy metals and contaminants to provide women with natural, safe, and effective potent beef liver capsules. Only produce beef organ supplement for women you will trust!
This comprehensive organ meat formula provides whole-food nutrients including lung tissue to support respiratory health and immune function naturally.
Organ meats offer concentrated nutrients that support immune function, including vitamins A, D, B12, iron, zinc, and CoQ10 – all crucial for respiratory immunity. The inclusion of beef lung tissue follows the traditional “like supports like” principle, providing targeted nutrients for respiratory health. This 12-organ blend delivers a complete spectrum of bioavailable nutrients in their natural food matrix, offering superior absorption compared to synthetic vitamins.
What We Like
- Comprehensive 12-organ blend provides diverse nutrients
- Includes lung tissue for targeted respiratory support
- Whole-food nutrients offer superior bioavailability
- Rich in immune-critical vitamins and minerals
What Could Be Better
- Not suitable for vegetarians or vegans
- May have mild organ meat taste despite encapsulation
Bottom Line: For those embracing ancestral nutrition approaches to respiratory immunity, this comprehensive organ supplement delivers whole-food nutrients in their most bioavailable form.
5. EZ Melts Vitamin C – Fast Absorption
- Vitamin C Supplement: EZ Melts Vitamin C is formulated to dissolve quickly in your mouth, so keeping up with your health is easy and convenient
- Immune & Antioxidant Support: Formulated to provide antioxidant protection and immune support while supporting healthy energy levels*
- Overall Wellness & Skin Support: Vitamin C helps support collagen production, protect cells from oxidative stress, and support healthy skin and vitality*
- Daily Vitamin C Tablets: As a dietary supplement, take two dissolvable vitamin C tablets a day or as recommended by your healthcare professional
- Non-GMO & Vegan Supplement: EZ Melts makes it easier to take superior quality vitamins—free from artificial flavors, gluten, dairy, soy, and sugar
These quick-dissolving vitamin C melts provide rapid absorption for antioxidant support and respiratory immune defense.
Vitamin C is essential for respiratory immunity, supporting the epithelial barrier function of the lungs and enhancing immune cell activity. The melt format offers faster absorption than traditional tablets or capsules, making it ideal for acute immune support. Each melt delivers 500mg of vitamin C along with complementary nutrients. The convenient format requires no water and dissolves quickly, making it easy to take throughout the day for sustained respiratory immune support.
What We Like
- Fast-melting format ensures rapid absorption
- No water needed for convenient dosing
- 500mg vitamin C supports respiratory defenses
- Easy to take multiple times daily if needed
What Could Be Better
- Melt format may not suit everyone’s preferences
- Contains natural sweeteners for palatability
Bottom Line: For fast-acting vitamin C support during respiratory challenges, these quick-dissolving melts offer convenient, rapid absorption for enhanced immune defense.
6. Metagenics Zinc A.G. – Highly Absorbable
- Superior Absorption: Provides zinc bound to arginine and glycine (amino acid chelates) for high absorption and gentle GI tolerance*
- Immune & Antioxidant Support: Essential for immune defense and antioxidant activity, helping protect cells from oxidative stress*
- Bone, Skin & Energy Metabolism: Supports bone health, tissue repair, healthy skin, and energy metabolism through zinc's role in over 300 enzymatic reactions*
- Clean and Trusted Formula: Non-GMO and gluten-free. Manufactured in GMP-certified facilities with third-party testing for purity and potency*
- As the #1 Doctor Recommended Professional Supplement Brand, Metagenics delivers clinically proven, precision-crafted formulas to support your health at its core‚ because true wellness starts with integrity, balance, and expertise
This professional formula combines zinc with arginine and glycine for superior absorption and enhanced respiratory immune support.
Zinc is critical for immune cell function and respiratory health, but absorption can be challenging. This formula pairs zinc with the amino acids arginine and glycine, creating a highly bioavailable complex that enhances uptake. Zinc supports the respiratory tract’s physical barriers, helps regulate inflammatory responses, and is essential for proper immune cell function. Metagenics is a practitioner-trusted brand known for science-based formulations.
What We Like
- Arginine and glycine enhance zinc absorption
- Supports multiple aspects of respiratory immunity
- Professional-grade formula from trusted brand
- 90-tablet supply offers three-month value
What Could Be Better
- Requires taking with food for optimal absorption
- Professional pricing reflects quality ingredients
Bottom Line: For enhanced zinc absorption to support respiratory immune function, this amino acid-chelated formula delivers superior bioavailability and professional-grade quality.
7. Algae-Based Astaxanthin Supplement 10mg
- Precision Dosage: Our astaxanthin supplements are made with a carefully dosed 10mg serving and include natural vitamin E and soybean oil to enhance absorption so you get more out of every softgel
- Made from Microalgae: We make our astaxanthin nutritional supplements with a remarkable freshwater green algae called Haematococcus Pulvialis packed with beneficial compounds including carotenoids
- The Clear Difference: At Clear Formulas we believe transparency and trust are essential which is why our product is made in an FDA inspected American facility according to strict regulatory guidelines
- Made for All in Mind: We stand by our name and our formula is made without many common allergens and additives including corn, dairy, gluten, silicon dioxide and artificial preservatives
- The Choice is Clear: We believe health doesn't have to be hard - We make it simple with carefully designed supplements to support your needs whatever your age and lifestyle we've got you covered
This powerful antioxidant from algae provides 10mg of astaxanthin to support respiratory health through potent oxidative stress protection.
Astaxanthin is one of nature’s most powerful antioxidants, offering significantly greater free radical-scavenging ability than vitamin C or E. For respiratory health, this translates to protection against oxidative damage from environmental pollutants and support for healthy inflammatory responses in lung tissue. The algae-based source ensures purity and sustainability. The 10mg dosage provides therapeutic levels backed by research for immune and respiratory benefits.
What We Like
- Potent antioxidant protects respiratory tissues
- 10mg therapeutic dose backed by research
- Algae-based source ensures purity
- Supports healthy inflammatory response in lungs
What Could Be Better
- Softgel format may not suit all preferences
- Premium antioxidant reflects in higher cost
Bottom Line: For powerful antioxidant protection of respiratory tissues and immune support, this high-potency astaxanthin formula delivers research-backed benefits for lung health.
8. CoQ10 Gummies with PQQ – 400mg High Potency
- 5-IN-1 SCIENCE-BASED FORMULA: Our co q 10 supplement provides 400 mg CoQ10 and 20 mg PQQ per serving, compared to coq10 300 mg, coq10 200 mg, or coq10 100 mg gummies, Ciaceae coq10 gummies 400 mg has maximum strength CoQ10 & PQQ, enhanced with Ayurvedic Herb Blend, Adaptogenic Mushroom Blend, Probiotics, the highest potency available for heart function, energy, and offers superior antioxidant protection
- UNIQUE PROPRIETARY 2 BLENDS: Coenzyme Q10 400 mg gummies feature an Ayurvedic Herb 100 mg proprietary blend with Organic Ashwagandha, Holy Basil, and Amalaki which benefit immune function and overall vitality; Besides, Ciaceae CoQ10 Ubiquinone supplement contains an Adaptogenic Mushroom 100 mg blend with organic reishi, lion's mane, cordyceps, and chaga to cognitive function, complementing CoQ10 and PQQ benefits
- OVER 5X WELLNESS SUPPORT: BEST FOR MEN AND WOMEN. Why does Ciaceae co q10 add Ayurvedic Herb and Adaptogenic Mushroom - This dual approach ensures you receive the maximum benefits from each serving, addressing not only your immediate q10 needs but also long-term wellness goals for over 5X wellness approach
- ADVANCED PROBIOTIC SUPPORT: Each coq10 gummy serving includes 30 Billion CFU from four potent probiotic strains to gut wellness, digestion, and immune system strength. Probiotics gummies create a foundation for overall wellness
- NATURAL, DELICIOUS, SAFE: Easy to chew with a natural cherry flavor. Ciaceae co q10 gummies are vegan, gluten-free, and contain only 1g of sugar per serving (no extra added sugar), free from artificial colors for the best daily coq10 supplement choice
These high-potency gummies combine 400mg CoQ10 with PQQ to support cellular energy production crucial for optimal immune function.
CoQ10 supports mitochondrial function in immune cells, ensuring they have the energy needed for effective respiratory defense. PQQ enhances mitochondrial biogenesis, potentially increasing the number and efficiency of these cellular powerhouses. Together, they support the high energy demands of immune cells protecting your respiratory tract. The gummy format makes this powerful combination enjoyable to take, with 400mg CoQ10 providing therapeutic levels for immune support.
What We Like
- High 400mg CoQ10 dose supports immune cell energy
- PQQ enhances mitochondrial function
- Gummy format offers convenient, pleasant dosing
- Supports cellular energy critical for immunity
What Could Be Better
- Gummies contain natural sweeteners
- May require refrigeration to prevent melting
Bottom Line: For cellular energy support that enhances immune cell function and respiratory defenses, this CoQ10 + PQQ combination delivers powerful mitochondrial benefits in an enjoyable gummy format.
How to Choose the Best Respiratory Immunity Supplement
When selecting supplements for respiratory immunity, start by identifying your primary goals. Are you seeking general immune support, seasonal respiratory comfort, or protection against environmental challenges? Vitamin D and zinc provide foundational immune support essential for respiratory health. Antioxidants like vitamin C, quercetin, and astaxanthin protect lung tissues from oxidative stress. Specialized nutrients like CoQ10 support the energy-intensive immune cell activity in your respiratory tract.
Consider your dietary restrictions and preferences. Plant-based formulas using lichen-derived vitamin D3 and algae-based antioxidants suit vegan lifestyles. Whole-food nutrient sources like organ meats offer superior bioavailability for omnivores. Those preferring convenience might choose gummies or melts, while others prioritize traditional capsules or tablets.
Dosage matters significantly for immune nutrients. Vitamin D requirements vary based on sun exposure and baseline levels – higher doses (2000-5000 IU) may benefit those with limited sun exposure. Vitamin C can be taken in divided doses throughout the day for sustained support. Zinc should not exceed 40mg daily from all sources. Check labels carefully to ensure dosages align with your needs and don’t exceed safe upper limits.
Quality indicators include third-party testing, GMP certification, and transparent labeling of ingredient sources and amounts. Professional-grade brands like Designs for Health and Metagenics often command higher prices but deliver superior quality and research-backed formulations. Look for products that clearly state the form of each nutrient (D3 vs D2, chelated zinc vs zinc oxide) as this significantly affects absorption and effectiveness.
Timing and combinations also matter. Fat-soluble vitamins (A, D, E) absorb better with meals containing healthy fats. Some nutrients work synergistically – vitamin D with K2, vitamin C with zinc. Consider whether a single comprehensive formula or individual nutrients better suit your needs. Individual supplements allow precise customization but require managing multiple bottles, while combination formulas offer convenience at the cost of flexibility.
Benefits of Respiratory Immunity Supplements
Respiratory immunity supplements work through multiple mechanisms to strengthen your body’s defenses against airborne pathogens and environmental challenges. Vitamin D modulates both innate and adaptive immune responses in the respiratory tract, helping immune cells distinguish between harmless particles and genuine threats. This immune regulation reduces excessive inflammation while maintaining vigilant antimicrobial defenses.
Antioxidants protect respiratory tissues from oxidative damage caused by pollution, smoke, and inflammatory processes. Your lungs are constantly exposed to potential irritants, generating free radicals that can damage delicate lung tissue. Vitamin C, quercetin, and astaxanthin neutralize these harmful compounds, preserving lung function and supporting healthy inflammatory responses. This protection becomes especially important for those living in urban environments or exposed to poor air quality.
Nutrients supporting immune cell energy and function ensure your respiratory defenses can respond effectively to threats. CoQ10 powers the mitochondria in immune cells, providing the energy needed for vigorous immune responses. Zinc is essential for immune cell development and function, with deficiency impairing both innate and adaptive immunity. These nutrients ensure your respiratory immune system can mount rapid, effective responses when challenged.
Beyond direct immune effects, respiratory immunity supplements support overall lung health in ways that indirectly enhance defenses. Strong epithelial barriers prevent pathogen entry, proper mucus production helps trap and eliminate threats, and healthy inflammatory responses clear infections without causing excessive tissue damage. These supplements help maintain the physical and functional integrity of your respiratory system, creating an environment hostile to pathogens while supporting comfortable breathing.
Frequently Asked Questions
Can respiratory immunity supplements prevent colds and flu?
While no supplement can guarantee you won’t get sick, research shows certain nutrients may reduce the frequency, severity, and duration of respiratory infections. Vitamin D, zinc, and vitamin C have the strongest evidence for supporting respiratory immune function. These supplements work best as part of a comprehensive approach including good hygiene, adequate sleep, stress management, and a nutritious diet.
How long should I take respiratory immunity supplements?
Many respiratory immunity nutrients work best with consistent, long-term use. Vitamin D optimization may take 8-12 weeks, while antioxidant protection accumulates with daily supplementation. For general immune support, year-round use is appropriate. You might consider increasing dosages during cold and flu season or times of increased stress when your immune system faces additional challenges.
Should I take vitamin D year-round or just in winter?
Most people benefit from year-round vitamin D supplementation, as modern indoor lifestyles limit sun exposure even in summer. However, needs increase in winter months when sun angle prevents vitamin D synthesis from October through March in northern latitudes. Consider testing your vitamin D levels to determine your optimal dosage, which may vary seasonally based on sun exposure.
Can I take all these respiratory immunity supplements together?
Yes, these supplements generally work synergistically and can be taken together safely. However, consider total nutrient intake from all sources including food and multivitamins. Zinc shouldn’t exceed 40mg daily, and high-dose vitamin D may require K2 for optimal calcium metabolism. Spreading fat-soluble vitamins throughout the day with meals containing healthy fats optimizes absorption.
Are respiratory immunity supplements safe for children?
Many nutrients supporting respiratory immunity are safe for children but require age-appropriate dosages significantly lower than adult doses. Look for products specifically formulated for children, or consult a pediatrician about appropriate dosing of adult formulas. Vitamin D is particularly important for children’s immune development, but dosage should be based on age and weight.
Do respiratory immunity supplements help with allergies?
Some respiratory immunity supplements may help with allergy symptoms, particularly quercetin which helps stabilize mast cells and reduce histamine release. Vitamin D supports appropriate immune responses that may reduce allergic reactivity. However, supplements for general immune support differ from targeted allergy management. For significant allergies, work with a healthcare provider for comprehensive treatment.
How do I know if my vitamin D levels are adequate?
The only way to know your vitamin D status is through blood testing measuring 25-hydroxyvitamin D levels. Most experts recommend levels between 40-60 ng/mL for optimal immune function, though conventional ranges may be lower. If supplementing with high doses (5000 IU or more), consider testing every 3-6 months initially to ensure you’re reaching optimal levels without exceeding safe ranges.
Can smokers benefit from respiratory immunity supplements?
Smokers have increased oxidative stress and nutrient depletion, making supplementation particularly important. However, beta-carotene supplements should be avoided by smokers due to potential increased cancer risk. Vitamin C, vitamin E, and other antioxidants may help counteract some smoking-related damage, though quitting smoking remains the single most important step for respiratory health.
