Colds are common, especially in autumn and winter, when many people spend more time indoors and are exposed to various viruses. There is no single product that can guarantee you won’t get sick, but sleep, a nutrient-dense diet, recovery, physical activity, and adequate fluid intake are important parts of the body’s normal resilience. Some vitamins and minerals also have EU-authorised health claims related to the normal function of the immune system. Other substances are interesting from a general nutrition or antioxidant perspective, but should not be described as preventing, treating, or curing the common cold.
1. Vitamin C
Vitamin C contributes to the normal function of the immune system and to protecting cells against oxidative stress. It also contributes to normal collagen formation, which is important for the skin’s normal function and thus part of the body’s external barrier. Research on vitamin C and the common cold suggests that regular intake in some cases may influence the duration of illness or the perceived severity. Vitamin C supports the normal function of the immune system. Vitamin C Whole Food is suitable if you want to supplement your diet with vitamin C during periods when you want to prioritise immune function and antioxidant protection.
2. Zinc
Zinc is an essential mineral that contributes to the normal function of the immune system. It also helps protect cells against oxidative stress and plays a role in the cell division process. Zinc has been studied in relation to the common cold, and some studies point to potential benefits when taken close to the onset of symptoms. Zinc bisglycinate or picolinate are easily absorbed forms of zinc if you want a daily supplement as part of a well-thought-out health routine.
3. Vitamin D3 2000 IU + K2 MK7
Vitamin D contributes to the normal function of the immune system and is therefore particularly relevant during the darker months of the year, when sun exposure is often lower. Vitamin D also helps maintain normal bones and normal muscle function. There is research that has examined vitamin D in relation to respiratory infections; although results vary between different studies and populations, vitamin D undoubtedly contributes to the normal function of the immune system. Vitamin D3 2000 IU + K2 MK7 is a good daily supplement during periods with limited sunlight. It can be especially relevant if you rarely spend time in the sun, use sunscreen, have dark skin and live at northern latitudes, or when the UV index is below 3.
4. Olive leaf extract
Olive leaf extract contains natural polyphenols, including oleuropein, and has been studied from an antioxidant and phytonutrient perspective. Anecdotal evidence describes olive leaf extract as a supplement that counteracts viruses, infections, or colds. Olive leaf extract is a plant-based supplement with interesting bioactive compounds. Olive leaf extract suits those who want to complement their daily routine with polyphenols from olive leaves.
5. NAC – N-Acetyl-L-Cysteine
NAC is a form of the amino acid cysteine and is often used in supplements as a precursor to glutathione, an important antioxidant in the body. NAC is therefore mainly relevant in contexts where you want to focus on antioxidant-related processes. NAC – N-Acetyl-L-Cysteine is therefore a good option if you are looking for a supplement focused on the body’s antioxidant defences. NAC is the active substance in expectorant medicines. It works by breaking down the bonds in mucus so that it becomes more fluid and easier to cough up, for example in prolonged bronchial problems.
6. Quercetin
Quercetin is a flavonoid that occurs naturally in onions, apples, and berries. Flavonoids are often studied for their antioxidant properties. Quercetin has been investigated in studies related to upper respiratory tract infections. There is some human research, but the evidence is not yet strong enough to make clear claims that quercetin prevents colds, even if the research is promising.
7. L-Lysine
L-lysine is an essential amino acid, which means the body cannot produce it on its own. It therefore needs to be supplied through the diet and is incorporated into proteins used in many normal physiological processes. The connection between L-lysine and the common cold is not as strong as for, for example, vitamin C, vitamin D, zinc, and selenium. L-lysine is, however, used to manage and shorten outbreaks of herpes simplex virus (HSV).
8. Probiotics
A large share of the body’s immune-related activity occurs in close interplay with the gut. The gut microbiota influences, among other things, the intestinal barrier and the communication between the gut and the immune system, which makes gastrointestinal health relevant for counteracting viruses and bacteria. Research on probiotic bacterial cultures and upper respiratory tract infections shows promising but variable results. The effect seems to depend on factors such as bacterial strain, dose, duration of use, and the individual’s health status. Flora Plus+ is a probiotic with many different and, in the gut, naturally occurring strains.
Things to consider during cold season
The foundation of a well-functioning immune system is always a healthy lifestyle: sleep, nutrient-dense food, regular movement, recovery, and stress management. Supplements can be a complement, but they do not replace a varied diet or medical evaluation when you are ill. Consult a doctor, dietitian, or other qualified healthcare provider before starting new supplements if you are pregnant, breastfeeding, taking medications, or have a medical diagnosis.
