It is about three in the afternoon, and in the office pantry a colleague drops a fizzing tablet into her water bottle and announces that it is her "jerebu defence". She says it with such confidence that you stand there holding your kettle and wonder whether she knows something you do not. Is there a vitamin you are supposed to be taking?
This guide answers that question honestly: do vitamin C and antioxidant supplements protect you from haze? The short version is no, not in any way that has been established, although the research is more interesting than a flat "no" suggests. Below we walk through what the studies actually found, why those results cannot be turned into a promise, what really lowers your exposure, and how to read "haze defence" claims on labels. It sits alongside our main haze survival guide for Malaysian women.
What you'll learn
- The short answer on vitamin C, antioxidants and haze, based on three published research sources.
- What each study found, and why you cannot generalise it to a healthy adult taking vitamin C alone.
- What the DOE and MOH advise instead, which lowers exposure directly.
- How to read supplement labels and who should check with a doctor first.
Related guides
- For the API bands and what to do at each level, start with the main haze guide, or the family guide to haze if you are caring for children, pregnancy or older parents.
- Antioxidants and skin are often mixed up with haze: our haze skin routine and haze and hair fall guide keep the focus on what is supported.
- For a plain-language explanation of free radicals, read understanding oxidative stress and dull skin.
What is the short answer on vitamins, antioxidants and haze?
No supplement has been shown to protect you from haze. A few small studies suggest that certain antioxidant combinations may influence lung-function measurements in particular pollution settings, mostly ozone and traffic-related pollution rather than smoke haze, but the results are mixed and the evidence is limited. The first line of defence is reducing your exposure, as the Department of Environment (DOE) and the Ministry of Health (KKM) advise.
An antioxidant is a substance that can neutralise free radicals, which are unstable molecules that can stress cells. Air pollution is thought to increase this "oxidative stress", which is why antioxidants are an obvious thing to test. But a plausible idea is not the same as a proven benefit, and that gap is what the research below is about.
What did the research find?
We looked at three sources: one randomised trial and two systematic reviews. The table sums them up, with the limits that stop us from stretching them.
Read plainly, those results say: in some settings, certain antioxidant combinations are interesting; vitamin C on its own has mostly not shown a protective effect on the heart in the reviewed trials; and researchers themselves call for more studies.
Why does "might help in a study" not mean "protects you"?
A few reasons the evidence cannot be turned into a promise:
- Different pollution. The trial and many of the reviewed studies looked at ozone or city traffic pollution. Haze from smoke is a different mixture, and the studies do not tell us what happens in a smoky haze.
- Different people. The best-known trial was in children with asthma, a group that is very sensitive to ozone. It does not tell us about a healthy woman taking one vitamin C capsule.
- Different supplements. The positive lung-function signals were mainly for vitamin C and vitamin E together. Vitamin C alone mostly did not protect the heart in the reviewed trials.
- Different outcomes. Lung-function measurements are not the same as fewer coughs, fewer hospital visits or less illness.
- Small, varied trials. Even the systematic reviews say the evidence is limited and mixed.
What actually lowers your haze exposure?
The reviewers themselves point out that public health efforts emphasise reducing exposure, and so do Malaysian authorities. The measures that the DOE, KKM and the Malaysian Medical Association (MMA) advise are:
- Check the API, and cut back on vigorous outdoor activity as it rises (the DOE's API guide advises reducing it at 101–200 and avoiding it at 201 and above).
- Keep windows and doors closed, and use filtered air where you can (the MMA suggests HEPA air purifiers).
- If you need to be outdoors, wear a properly fitted N95 respirator, as KKM and the MMA recommend.
- Look after people at higher risk, and seek treatment promptly for shortness of breath, a persistent cough or eye irritation, as KKM advises.
Our main haze guide covers each of these, and our mask guide explains fit.
Food matters too, as part of a generally healthy diet rather than a haze shield. The WHO recommends at least 400 grams of fruit and vegetables a day for everyone older than 10. We mention it as general nutrition, not as protection from haze.
How do you read "haze defence" claims on labels?
Marketing tends to sprint ahead of research. Use this checklist when you see a product promoted for haze:
- Be wary of any claim to protect, shield or "cleanse" you from haze. The research does not support it.
- Check who the claim applies to. If it quotes a study, was it in people like you, taking that same product at that dose?
- Check registration and halal status. Our guide on how to verify KKM registration and halal status for supplements explains what to look for.
- Ask a pharmacist. They can tell you whether a supplement might interact with medicines you take.
- Compare with the free options first. Closing windows, checking the API and wearing a properly fitted mask cost little and are supported by the DOE and KKM.
Who should check with a doctor first?
Talk to your doctor or pharmacist before taking a new supplement if you are pregnant or breastfeeding, have a medical condition, or take regular medicines. If you have asthma, COPD or heart disease, never swap prescribed medicines for a supplement, and follow the plan your doctor gave you. Our family guide to haze explains what to do for each member of your household.
A note on Drann Vitamin C
Since this is Drann's blog, here is a plain fact sheet rather than a claim. Drann Vitamin C is a 500 mg vitamin C capsule that uses a patented form called PureWay-C, which its product page says is sourced from the USA and enhanced with citrus bioflavonoids. The page lists the recommended dosage as one capsule daily, describes it as vegan and fermented from non-GMO corn, says the PureWay-C ingredient is Halal and Kosher certified, and says it is manufactured in Taiwan under GMP standards. It is a vitamin C supplement. It is not a haze protection, and nothing in this article suggests that it prevents or lessens the effects of haze.
Common myths (quick reality check)
- Myth: Vitamin C will protect my lungs from the haze. Reality: Most vitamin C studies in the reviewed trials did not find protective cardiovascular effects, and the positive lung-function signals were mostly for vitamins C and E together in specific settings. No supplement has been established to protect people from haze.
- Myth: If a study showed a benefit in asthmatic children, it applies to me. Reality: That trial was in children with asthma, studied ozone, and used vitamin C plus E; the authors only suggest antioxidants "might" influence small-airway effects.
- Myth: More antioxidants must mean more protection. Reality: Researchers say more studies are needed to find out whether these supplements work and at what dose, so there is no basis for taking more.
Frequently asked questions (FAQ)
Should I take vitamin C during the haze?
There is no evidence that vitamin C protects against haze. If you take it for other reasons, follow the label, and check with your doctor or pharmacist if you are pregnant, breastfeeding, have a medical condition or take regular medicines.
Are fish oil or N-acetylcysteine better than vitamin C for haze?
The 2024 systematic review found limited evidence that fish oil may help lung function and said that N-acetylcysteine and some other supplements showed potential but need more research. That is not enough to recommend any of them for haze.
Can a supplement replace wearing a mask?
No. The DOE and KKM advice is to reduce exposure, and KKM and the MMA recommend a properly fitted N95 if you must be outdoors. No supplement has been shown to replace those steps.
What is the best "haze defence" then?
Closing windows, using filtered air, checking the API, limiting vigorous outdoor activity and wearing a properly fitted N95 if you must go out. Those are what the DOE, KKM and the MMA advise.
Disclaimer and when to seek help
This article is for general education and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Supplements are not a substitute for avoiding exposure to haze, and they do not replace medical care. See a doctor for shortness of breath, chest pain, a severe or persistent cough or any symptom that worries you, and ask your doctor or pharmacist before starting a supplement if you are pregnant, breastfeeding, have a medical condition or take regular medicines.
References
- Antioxidant supplementation and lung functions among children with asthma exposed to high levels of air pollutants — Romieu et al., American Journal of Respiratory and Critical Care Medicine (2002)
- Modification by antioxidant supplementation of changes in human lung function associated with air pollutant exposure: a systematic review — Tashakkor et al., BMC Public Health (2011)
- Dietary supplementations to mitigate the cardiopulmonary effects of air pollution toxicity: a systematic review of clinical trials — Ilaghi et al., PLOS ONE (2024)
- Healthy diet — World Health Organization fact sheet
- A Guide to Air Pollutant Index in Malaysia (API) — Department of Environment Malaysia
- Jerebu: KKM tingkat pemantauan kesihatan awam — Portal Berita RTM (Bernama), 29 Aug 2026
- Haze: MMA advises vulnerable groups to limit outdoor activities — The Star, 24 Sep 2026
