The first line of protection against viruses and colds is good hygiene, but there are some supplements that can help. Let's see what this is about!
Colds and influenza are caused by viruses that pass from one person to another. The body fights infections all year, but during the colder months it is more sensitive: the cold environment weakens the immune system and the cold weather makes you spend more time indoors, along with other people, which increases your chances of getting a virus or microbe.
How do you reduce the risk of cooling? Can you:
Eat healthy, nutrient dense foods.
You have minimal contact with sick people.
You drink lots of fluids.
You manage stress in your life.
You wash your hands.
Don't touch your eyes, nose or mouth.
Unfortunately, and if you follow these steps rigorously, you can still get bad luck and get a virus or get the flu. So, in the cold months and, more recently, with the coronavirus outbreak, one of the most frequently asked questions is, what supplements are there that will strengthen the immune system and fight the viruses? Fortunately, there are such supplements!
Supplements supported by moderate evidence
Evidence regarding the benefits of vitamin C, vitamin D and zinc is often mixed, but suggests a positive effect.
Vitamin C is sold as the basic supplement for the prevention and treatment of colds. It seems logical: Vitamin C helps immune cells form and function and supports the physical barriers (such as epithelial cells in the skin) that protect you from pathogens. More than 148 animal studies have shown that vitamin C helps prevent infections with microorganisms.
But these animal studies do not answer the question whether vitamin C can prevent colds in humans! A meta-analysis from 2013 tried to answer the same question, and here are the main conclusions reached:
Those who start taking vitamin C when they are already chilled, do not benefit much. Some studies suggest that very high doses (several grams) can reduce the duration of colds.
Those who are supplemented regularly with vitamin C have shorter colds (by 8% in adults and 14% in children) and with somewhat less severe symptoms.
Athletes who take vitamin C on a regular basis are 50% less likely to chill compared to athletes who do not regularly supplement with vitamin C. Only those who exercise intensely on a regular basis benefit from this aspect.
Another meta-analysis from 2018 supports the idea that vitamin c shortens the duration of colds.
Vitamin D receptors are found throughout the body, and vitamin D is involved in many cellular processes, including regulating immune cell functions in the type of infections. A deficiency of vitamin D can negatively affect immunity. And most of us are deficient!
Epidemiological studies show an association between low levels of vitamin D and increased risk of viral airway infections. Vitamin D supplementation can prevent asthma symptoms and respiratory infections!
More is not necessarily better: a 2017 randomized study found no statistically significant differences between doses (taken by children) of 400 U.I./zi and 2000 U.I./zi.
Zinc has many roles in the body - some of which are immune. If you cool easily, be sure to consume enough zinc. Athletes and those who sweat a lot have a higher risk of zinc deficiency. And taking too much zinc is a risk, so be careful!
Zinc tablets can limit virus replication in the nasal epithelium and reduce respiratory tract infections. If zinc tablets are suggested throughout the day (75-95 mg of zinc daily, starting with 24 hours after the onset of symptoms), the duration of the cold can be reduced by 2-4 days. Zinc acetate pills are slightly more effective than gluconate zinc (a more common form).
Zinc tablets may cause nausea and change in taste perception, but these symptoms disappear when supplementation ceases.
Effective doses of zinc for reducing the duration of colds (75-95 mg / day) are beyond the limits considered safe (40 mg / day). You should not suffer from anything if you take 100 mg / day of zinc for 2 weeks, but if you start to have symptoms of nausea, vomiting, loss of appetite, stomach cramps, diarrhea or headaches, stop taking it.