Key takeaways
- Sleep, vaccination and hand hygiene have the strongest evidence for fewer infections.
- Vitamin D helps most if you are low. Zinc lozenges may shorten a cold slightly.
- Vitamin C does not prevent colds in the general population. Quercetin and elderberry have thin evidence.
The unglamorous basics
In a study that quarantined healthy adults with a cold virus, people who slept under six hours a night were roughly four times as likely to catch a cold as those sleeping seven or more. Seasonal vaccination against influenza and COVID-19, handwashing and staying home when ill remain the best-supported ways to cut infections. Our sleep calculator and recovery score help you track the basics.
Vitamin D
A large pooled analysis of randomized trials found vitamin D supplementation modestly reduced acute respiratory infections, with the clearest benefit in people who were deficient and who took it daily or weekly. If you are not deficient, the benefit is small or absent. A blood test tells you where you stand.
Zinc
Cochrane reviews found zinc lozenges or syrup started within a day of cold symptoms may shorten a cold, but side effects such as nausea and a bad taste are common, and evidence on best dose is mixed. Long-term high-dose zinc can cause copper deficiency.
Vitamin C
The Cochrane review found regular vitamin C does not reduce how often people get colds, apart from people under extreme physical stress, and shortens colds only slightly.
Elderberry and quercetin
A meta-analysis suggested elderberry may reduce upper respiratory symptoms, though the studies were small and varied. For quercetin, human evidence of immune benefit is limited. It can also interact with some medicines.
Check your total doses
It is easy to double up on vitamin D and zinc across products. Add yours in the supplement stack checker.
A product to consider
NuviaLab Immune
Per the seller’s page, two capsules provide about 50 µg (2,000 IU) of vitamin D, 10 mg of zinc, vitamin C, quercetin, elderberry, rosehip, rutin and a yeast extract.
- Vitamin D at 2,000 IU and zinc at 10 mg are within common upper limits.
- The mix of familiar nutrients is simple to understand.
Consult your doctor before use, especially if you are pregnant or breastfeeding, have a medical condition or take medication. This product is not intended to diagnose, treat, cure or prevent any disease.
Try the related tools
Sleep calculator · Recovery score · Supplement stack checker
Sources
- Cohen S et al. Sleep habits and susceptibility to the common cold. Arch Intern Med 2009. Find on PubMed
- Martineau AR et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ 2017. Find on PubMed
- Singh M, Das RR. Zinc for the common cold. Cochrane Database Syst Rev 2013. Find on PubMed
- Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2013. Find on PubMed
- Hawkins J et al. Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: a meta-analysis of randomized controlled trials. Complement Ther Med 2019. Find on PubMed
Links open a PubMed search for each paper so you can read the abstract and full citation. Always check the original study.