At this point, it’s likely you’re well aware of the plethora of benefits that come from vitamin C. For years, the nutrient has been rapidly rising in the beauty and wellness spaces thanks to its ability to aid in everything from free radical protection and immune function to iron absorption. In fact, on TikTok alone, #vitaminc has garnered some 2.8B views to date, with users sharing products, skin care, foods, and supplements that star the buzzy antioxidant.

“It also helps to boost collagen production and decrease inflammation in the body, making it an essential nutrient for bone and blood vessel health,” anti-aging and regenerative medicine doctor, Dr. Neil Paulvin, DO explains. And while there’s a plethora of information on what it can do for the body, how does one know if they’re deficient in it?

The thing with this tricky nutrient is that, unlike iron and B12-deficiencies, vitamin C disparities can sneak up on you as symptoms — like not getting enough sleep, catching a cold, fever, etc. — can easily be mistaken for a wide variety of other issues. That said, Sanjay Batra, PHD says it’s also one of the vitamins you need to keep in check as having healthy amounts of vitamin C cannot be underestimated. The key thing to note here is that this nutrient cannot be made by the human body, so it must be absorbed through food or supplement. For reference, adult women should be consuming at least 75 mg of vitamin C daily. “While the body can store vitamin C, to get through times of scarcity, the stores are eventually depleted,” says Barta.