According to an article published by Harvard Health, the bulk of evidence shows that high-dose vitamin C will, at most, shorten a cold by one day.
But there does seem to be a consensus among our experts that vitamin C can support the immune system. Daya notes that while it’s not entirely known how vitamin C does this, “studies do indicate that supplementing vitamin C can reduce the incidences of colds.”
On the flip side, lower levels of vitamin C “can compromise the immune system, putting you at greater risk of sickness, infections and viruses over winter,” adds Dr John Burke, a physician with over 25 years experience and chief medical officer at AXA Health.
What are 7 signs you might want to up your vitamin C intake?
First things first. It’s highly unlikely that you’re actually deficient in vitamin C as we have access to plenty of fresh fruit and vegetables (smokers beware, though, that puffing on cigarettes reduces the absorption of vitamin C).
There are, however, telltale signs that your reserves may be running low and that you may not be taking your vitamin C supplement correctly.
1. You’re suddenly catching every cold doing the rounds
“Each stage of our immune response relies on the presence of different micronutrients, which are critical to its function, like vitamin C, vitamin D, zinc, selenium, vitamin A, iron, and different amino acids,” says Stephenson.
Studies show that vitamin C, in particular, is found at high levels inside many immune cells to help your body combat infection.
2. Your skin is dry and rough
“Skin is your largest organ and it can say a lot about your health,” notes Daya. “A lot of nutrients that are famously found in skincare, including vitamin C, have to be provided from within the body to make a real difference to the skin.
“Increasing your dietary intake of vitamin C has been correlated with a decreased risk of dry skin,” he continues. “Studies indicate that vitamin C enhances the production of barrier lipids, called ceramides, which protect skin against water loss.”
Given vitamin C also plays a role in collagen production—a protein responsible for strengthening the skin’s structure and keeping it looking plump—it follows that when vitamin C levels are low, skin can become dry, wrinkled and rough to the touch.
3. You’re often tired and grumpy
“Vitamin C is required for the manufacture of norepinephrine, a neurotransmitter that affects our mood and our ability to feel energized,” Daya says.
4. You’re low in iron
Iron deficiency anemia and vitamin C often go hand in hand. “Iron is involved in red blood cell formation and is required to transport oxygen throughout our entire body, making it an essential mineral for energy, immunity, cognitive function, and pregnancy,” says Stephenson.
