Could taking vitamins, minerals, or other supplements help protect you from COVID-19? Contrary to what you might read on the internet, this is a question that can’t be answered definitively. Here’s what we do know about certain supplements that reportedly have immune-boosting properties.
For decades, Vitamin C has been used to help prevent the common cold. Among other functions, this vitamin can help maintain healthy skin that provides a barrier to germs and other harmful invaders. In addition, some — but not all — studies suggest it may improve the function of certain white blood cells that fight infection.
In addition, there is conflicting evidence about the potential mortality benefits of high dose Vitamin C for patients with sepsis, the most severe form of systemic infections.
While it’s unclear whether taking a Vitamin C supplement is beneficial for COVID-19, for most people there’s no harm in taking up to 2,000 mg per day (the upper limit set by the National Academy of Medicine).
For smokers and high-risk individuals, it’s definitely worth considering. Vitamin C is water-soluble, so your body will excrete whatever you don’t need into your urine. However, at very high doses, Vitamin C may cause diarrhea or increase the risk of kidney stones (especially in men), so be sure not to exceed 2,000 mg daily.
As both a hormone and a vitamin, Vitamin D plays a number of important roles in health.
In recent years, people have taken very high doses of Vitamin D with the intention of boosting immunity. But is this an effective tactic? A 2017 systematic review of 25 randomized trials found that taking a Vitamin D supplement seemed to have a mild protective effect against respiratory tract infections in most people, but provided much greater protection in those who were very deficient in Vitamin D.
If your Vitamin D levels are low, you may have a better chance of staying well if you supplement with 2,000 IU per day (or more, with medical supervision). Many — perhaps even most — people are deficient in vitamin D.
So it’s probably wise to take a Vitamin D supplement right now, especially if you’re at increased risk for COVID-19.
Of course, your body can make Vitamin D on its own when your skin is exposed to sunlight, so try to get some sun whenever you can. How much sun depends on the time of year and your location. A good starting point is 15 minutes of exposure to a large body part (such as the torso or back). Just remember to avoid sunburns, as excess sun exposure carries its own risks.
Zinc is a mineral involved in the white blood cell response to infection. Because of this, people who are deficient in zinc are more susceptible to cold, flu, and other viruses. One meta-analysis of seven trials found that supplementing with zinc reduced the length of the common cold by an average of 33%.
Whether it could have a similar effect on COVID-19 isn’t yet known.
Taking supplementary zinc may be a good strategy for older people and others at increased risk. If you decide to take zinc, make sure to stay below the upper limit of 40 mg per day, and avoid administering nasally, due to the risk of olfactory complications.
Turmeric is a spice commonly used in Indian and Asian cuisine, including curries. It contains a bright-yellow compound known as curcumin, which emerging research suggests might enhance immune function.
However,there isn’t any convincing evidence showing that it helps fight viral infections yet.
On the other hand, adding turmeric to your food adds flavor, and taking a curcumin supplement is unlikely to cause any harm in otherwise healthy people. If you have any medical conditions — especially if you take blood thinners — check with your doctor before supplementing with curcumin.
Echinacea is an herb that can reportedly help prevent the common cold. But is this reputation well-deserved? A recent systematic review of randomized trials found that echinacea may possibly have a mild protective effect against upper-respiratory infections but doesn’t appear to reduce the length or severity of illness.
While it’s impossible to say whether it might offer any protection against COVID-19, it appears to be safe to take on a short-term basis. If you’re at high risk, you may consider taking it for the next several weeks.
Garlic, a popular and pungent herb with a characteristic aroma, is widely believed to have antibacterial and antiviral effects, including helping to fight the common cold.
A 2014 randomized controlled trial did find that people who took a garlic supplement had fewer colds and recovered more quickly from colds than people who didn’t take garlic.
Although this is encouraging, this is just one study. Other high-quality trials are needed to confirm whether garlic is truly beneficial for the common cold or other upper-respiratory infections. For now, enjoy garlic for its zesty flavor and unmistakable aroma rather than counting on it to boost your immunity during the coronavirus pandemic.