How Sugar Steals Vitamin C From Your Cells

by DailyHealthPost Editorial

Vitamin C is one of those vitamins that are relatively well-known to people outside of the medical sciences. Common sources of vitamin C include oranges, lemons, grapefruits and bell peppers. On par in popularity with vitamin D which is famously derived from the sun’s UVB rays, vitamin C is hardly intriguing to most people. Yet, we’re still not getting enough of it. In fact, we eat way too much sugar which is has been found to “steal” our vitamin C. 

Sure, most of us are getting enough vitamin C to avoid suffering from scurvy but we’re usually still not getting enough to enjoy the many different benefits of vitamin C. And with recent revelations of how vitamin C is helpful against Covid-19, it makes sense to want to pay extra attention to your vitamin C intake.

Why is vitamin C so good?

Vitamin C has an almost unparalleled antioxidant power which is why it’s great to combat oxidative stress. Because of that it greatly reduces the risks of most autoimmune diseases. Vitamin C accomplishes that by entering our cells and strengthening them against free radical molecules. 


Vitamin C also relaxes blood pressure and can help people with both low and high blood pressure. It also reduces the blood’s uric acid levels and prevents gout attacks (a type of arthritis). Probably most famously, vitamin C also reduces the risk of heart diseases. It also prevents iron deficiency, boosts our immunity systems, and much more.

How eating sugar “steals” your vitamin C?

To utilize the antioxidant potential of vitamin C our white blood cells need to have over 50 times more vitamin C in their cell walls than there is in the surrounding blood plasma. This can be difficult to achieve, however, because our bodies don’t actually have the ability to produce vitamin C – we can only take it from food and supplements. To make matters worse, consuming too much glucose can deprive our cells of the vitamin C that we’ve eaten, essentially nullifying its effects.

How does this happen?

This isn’t something new. We’ve known since the 1970s that sugar and vitamin C enter our cells through the same “doors”, namely the Glut-1 receptors. That makes sense since animals that are able to synthesize their own vitamin C do so through glucose. This has also led some scientists such as Nobel Prize-winning chemist Linus Pauling to believe that humans were also able to synthesize vitamin C at one point but we’ve lost that ability over time. 

All that has a nasty side-effect, however – when we consume sugar it gets within our cells and “takes the place” of vitamin C. Not only that, but our white blood cells actually “prefer” to take the sugar instead of the vitamin C when given the chance. Add to that the fact that consuming too much glucose also leads to more free radicals in our systems and sugar becomes a clear “nemesis” to vitamin C.

What does all this mean?

In short, when you’re trying to up your vitamin C intake you should also keep your sugar intake into consideration. Even if you’re purposefully taking vitamin C supplements or you’re eating vitamin C-rich foods, the excessive sugar you eat can counteract them and leave you with insufficient levels of vitamin C in your system. 


So, there are two things you need to do:

  • Cut your sugar intake. Excessive sugar is pretty horrible for us anyway so, aside from its taste, you shouldn’t miss it. 
  • Take more vitamin C. The recommended daily intake of vitamin C is ~100 mg for adults. However, that’s not counting the sugar you’re eating or other problems or side factors that may require more vitamin C. 

Fortunately, vitamin C is water-soluble which means that you can’t really overdose on it – our bodies simply excrete any excess through our urine. There are some possible side effects of consistent and excessive intake of vitamin C such as diarrhea or nausea but reaching such extreme levels is pretty difficult. Plus, according to the Harvard T.H. Chan School of Public Health, the “Tolerable Upper Intake Level” (i.e. with no side-effects) is 2,000 mg a day.

Which foods are rich in vitamin C?

Aside from getting your vitamin C as supplements, you can also eat foods that are rich in vitamin C. The first food group won’t be a surprise to anyone but a few of the others may be new to some:

  • Citrus fruits such as oranges, lemons, and grapefruits
  • Chili peppers
  • Guavas
  • bell peppers
  • Fresh thyme
  • Mustard spinach
  • Kale
  • Brussels sprouts
  • Broccoli
  • Kiwi fruit
  • Persimmons
  • Papayas
  • Strawberries
  • Sweet potatoes
  • Tomatoes