Many of us are looking for ways to boost our immune system and protect ourselves from COVID-19, so we are increasingly turning to supplements. But if not used properly, those supplements could go from friend to foe very quickly.

Vitamin C is one of the best-known immune-boosters out there, but even this vital substance can be misused and cause negative side effects to your health. Overdosing on vitamin C usually occurs from taking it in supplement form, which is why experts recommend ingesting most of your vitamin C through food, where the chances of getting too much are virtually zero.

Vitamin C has been lauded as a useful supplement in the battle against coronavirus. Clinical studies have shown that it can help with recovery in patients with severe COVID-19 symptoms.

Read on to find out how much of the supplement is safe to take, and the health issues taking too much of it could cause. And don't miss The 7 Healthiest Foods to Eat Right Now.

According to Dr. David Hernandez, a urologist and professor for at University of South Florida, it's best to get vitamin C from your diet. Taking too much of the supplement could lead to kidney stones over time, he warns.

"There are some studies suggesting that not dietary, but supplemental vitamin C at doses more than a gram a day, a thousand milligrams a day, can increase your risk for stones because of the effect of the oxalate levels in your urine increasing," Hernandez told WTSP.

Oxalate is a bodily waste product that rids you of excess vitamin C, normally through urine. In some cases, it can bind to minerals and form crystals, which is the cause of kidney stones.

To avoid this, eat a balanced diet of fruits, vegetables, and lean meats, which should provide you with enough vitamin C naturally. Here are 5 Foods High in This Vitamin That Can Help Protect You From COVID-19.

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You could suffer from digestive problems

Another likely symptom you'll experience if you consume too much vitamin C is digestive distress. While you won't get this issue from eating too many vitamin C–rich foods, overdosing on the supplement is likely to cause diarrhea, nausea, and sometimes acid reflux.

To avoid an upset stomach, you shouldn't take more than 2,000 milligrams of vitamin C supplements at once, as that's been identified as the tolerable upper limit per day.

You could damage your major organs

Vitamin C is known to increase iron absorption, but taking too much of it could lead to iron overload. In turn, this can cause serious damage to your heart, liver, thyroid, pancreas, and central nervous system, according to Healthline.

Iron overload is most likely to occur in individuals that have certain medical conditions, like hemochromatosis, which is a hereditary condition that increases iron absorption.