Vitamin C (Vit C) also known as ascorbic acid or ascorbate, is the most familiar of all the vitamins. Sailors on long marine voyages suffered deadly effects of bleeding gums, hemorrhaging, and slow healing (eyew), a condition known as “Scurvy”. It was discovered in the 1700’s that bringing citrus fruit like limes (British sailers were called “limeys” for that reason) on voyages eliminated these deadly symptoms. Vit C was isolated and accurately described in 1928 by Hungarian Albert Szent-Gyorgyi who won a Nobel Prize for the discovery.
Vitamin C has since been found to play many other roles in the human body: it is an antioxidant, protects against skin DNA damage by scavenging free radicals caused by UV-exposure, boosts absorption of iron in the small intestine, assists in making collagen in the skin, thus speeding wound healing, and many other important functions.
These days, most of us in the western world do not suffer from scurvy. In fact, we’ve sort of gone the other way. Vit C is now a multi-million dollar industry (think Emergen-C packets, fortified cereals and other foods) stemming from the idea that if a little bit is good, more is better. Actually, this is not true of Vit C. Though we do not make it, we don’t store it, so any excess of what is needed is simply wastefully excreted. According to federal NIH guidelines, the daily “scurvy-prevention-plus-a-little-more” requirement is 75 - 90 mg. According to the Linus Pauling Institute, it is more like 200 - 400 mg for regular folks, a little more if you are working out heavily, are over 60, or have an intestinal absorption issue.
Since a bit too much Vit C only causes something my grandmother adorably called “the collywobbles” I’d go with 200-400 mg a day, something easily achieved if one’s diet contains adequate fresh fruits and vegetables. You don’t need thousands of milligrams per day, as suggested in the ‘70s, unless you are battling illness.
Does large amounts of Vit C help to stave off a cold or virus? Though originally purported to have such properties, unfortunately more recent science points towards ‘Not Really’. It might reduce your cold duration by a day, but that’s about it. Though those who would like to sell you supplements will protest and point towards outdated articles and anecdotal evidence. Don’t be fooled.
We don’t make Vit C, we must obtain it from food. Vit C is heat-labile, meaning is it sensitive to heat. The longer food is cooked, the more Vit C (and other vitamins) is lost. For example at 140F, 10% of the food’s Vit C is lost in 5 minutes and more than 60% is lost in 30 minutes. Most cooking is done at much higher temperatures that 140F, so Vit C is not reliably obtained in cooked food. The best dietary sources are fresh raw fruits and vegetables; citrus fruits, colorful bell peppers, cruciferous vegetables (broccoli, cabbage and Brussels sprouts), tomatoes, papayas and others). Freezing apparently does not affect Vit C levels, so frozen veggies will give you more than cooked. The problem is that frozen veggies are pretty limp and icky once thawed, and really only fit for cooking. But wait - there are smoothies! Think about adding frozen spinach to your berry-and-cacao smoothie.
So what’s the takeaway (takeout? sorry, couldn’t resist)? As usual, you don’t need to buy expensive and unnecessary supplements like big vitamin C pills or packets. Eat lots of fresh raw veggies and fruits, and feel free to freeze them (or ferment them!) if your garden is spewing them out. Along with all the other beneficial nutrients, fiber and antioxidants plants provide, you’ll easily get delicious adequate doses of your daily Vitamin C.