Vitamin C Science: why does your body need it and where to get it from?
I’m sure your mom told you to eat your fruits because it contains vitamin C and that’s very good for you. Ever wonder what vitamin C exactly is and WHY it’s good for you? I’m sure your mom didn’t have any clue… Let’s explore:
Vitamin stand for vita (vital) + amine (think amino acid), they represent a class of vital nutrients that our body cannot sufficiently synthesise and must therefore get from our diet. Not all vitamins contain amino acids but the name stuck.
Vitamin C (aka ascorbic acid) works as an antioxidant, cleaning up free radicals and reducing oxidative stress. This prevents damage to cells and DNA breaks. It’s also essential for the synthesis of collagen, a structural protein abundant in bones, cartilage, blood vessels and skin. Its chemical structure allows it to donate electrons to various enzymatic reactions in cells, and makes it water soluble. We need a daily intake as excess amounts are not stored (unlike vitamines A, D, E & K) but leave the body via urine.
Recommended intake is around 75–90 mg per day, but a higher intake is absolutely fine as you pee out whatever your body doesn’t need. Side effects like diarrhea have only been reported with doses exceeding 3000 mg per day. This requires eating more than 6 kg of oranges a day so I wouldn’t worry too much. Don’t take too many vitamin C supplement pills though as some contain 1000 mg per pill.
Fruits and veggies are the main sources of Vitamin C
Oranges are often pointed at for their high vitamin C content, though we now know that other fruits and veggies contain even higher vitamin C levels. In 1747 a Royal Navy surgeon named James Lind supplied sailors with two oranges a day on top of their normal ration. This proved to be a very effective way of preventing loss of life to scurvy on long voyages. Similarly, Captain James Cook supplied sauerkraut to his crew, with similar effects. Sauerkraut contains 15 mg vs. 53 mg for oranges per 100 g.
Fruits and veggies with a high vitamin C content (per 100 g) are chili peppers (244 mg), guava (228 mg), blackcurrant (200 mg), parsley (130 mg), kiwi (90 mg), broccoli (90 mg) and Brussels sprouts (80 mg), but basically any fruit or vegetables will contain a decent amount.
If you must eat meat, raw liver from pork, calf or beef as well as oysters also contain about 20–30 mg vitamin C per 100 g. Cooking can however decrease vitamin C levels significantly so fruits, veggies or supplements might be a more reliable source.
Vitamin C cures scurvy but not much more
Scurvy is a well-known disease common in sailors on long voyages pre 1800. The lack of vitamin C intake causes defects in collagen synthesis making your teeth fall out among many other symptoms. Taking vitamin C reverses all symptoms. Scurvy cases are rare these days, mostly caused by severe malnutrition. Some rare cases of students developing scurvy symptoms causes by a diet of fries and beer circulate but most cases are confined to third-world countries.
A few studies have found benefits of vitamin C intake and disease:
- In pooled data from 44 clinical trials vitamin C supplementation associated with improved endothelial function. Endothelium is the internal lining of blood vessels. Dysfunction can lead to cardiovascular events.
- In an ovarian cancer study, additional vitamin C intake reduced chemotherapy-associated toxicity.
- An additional 500 mg of daily vitamin C improved concentration in students.
- In a double-blind randomized controlled trial, IV-administered vitamin C reduces fatigue in office workers.
But other than these examples, a lot of studies have not shows any benefits of vitamin C supplementation in diseases, such as common cold, cardiovascular disease, rheumatoid arthritis, Alzheimer’s disease, and various types of cancer.
No doubt that vitamin C is responsible for a healthy body, but a regular diet may already provide sufficient vitamin C. Therefore additional vitamin C intake might not make much difference in disease progression. Obviously a more suitable experimental setup would be to have a control group with zero vitamin C intake over a prolonged time period, but there are quite some ethical issues with such an experiment.
Conclusion: eat your fruits dude.