Given that meat is high in purines and the breakdown of purines ultimately results in a large amount of urate, the excretion of which is increased by Vitamin C, one might reasonably assume that we paleo folks would find benefit in supplementing ascorbic acid daily. This is only one of many ways that animals use the vitamin, but it's one whose need would scale up with meat consumption. The urate decrease from less fructose would probably be to some extent balanced out by an increase from purine nucleotide breakdown.
While the SAD may increase the need for Vitamin C for some other reason (due to the increased fiber intake maybe as well as massive fructose intake maybe?), I'm not certain that the dismissive attitude toward vitamin C that I see often in our community, such as it is, is warranted.
Dogs apparently endogenously produce roughly 18mg of C per pound of bodyweight. In times of stress, they produce quite a bit more. A 180 pound paleo werewolf abomination might then manufacture 3.24 grams of the stuff.
Given that we humans are incapable of any endogenous production, one may desire to supplement with this surprisingly non-toxic water-soluble vitamin in similar doses.
I would however recommend against consuming fructose-rich foods in order to obtain ascorbic acid, especially if one is attempting to lose fat, since fructose is one of the most lipogenic substances known. To say nothing of the fact that fructose increases urate levels itself.
Paleolithic man would have eaten fruits, maybe rose hips in the winter, and chewed on leaves and whatever was around. Sorry, but I don't see how an all meat diet is mimicking any paleo lifestyle, except maybe those in polar regions, and even the Inuit eat sea weed, berries and other things available in the harsh climate. I don't know how the idea of an all meat diet translates to paleo, when eating would have been very based seasonally. Further, we don't have truly carnivorous teeth nor do we have flat teeth which suggest purely herbivorous diets. We have the teeth of omnivores, so vitamin C should have easily come naturally to the paleolithic humans because they would have grazed on all kinds of things throughout the year.
I expect this to get downvoted, but that won't make any of what I've written. I grew up in the country, playing in fields and woods. As a kid, I learned quickly that you can pull out red clover petals and suck on the white ends to get some sugary sap, and we all experimented with sucking the sap out of tall grasses when we pulled the soft part of it out of the stalk. We chewed on the ends. Indigenous people in many places chew on leaves for medicinal or pleasant effects. All of this supplements nutrition.
Ok so you have a hypothesis. Vitamin C will bring benefit. Sub-hypothesis: Heavy meat intake requires Vitamin C supplementation. What are your predictions with this hypothesis? How will you test them?
You must be aware of this study, the infamous Bellevue trial in which two men ate nothing but meat for a year without any supplementation and were in good health. Their meat intake was as high as would be possible (their entire diet) and their vitamin C intake was essentially as low as it could reasonably be, and they were fine.
So I'm curious to see how you square your hypothesis with this observation.
Are you considering vitamin C from the perspective of an antioxidant? If so, I would imagine that the system is to some degree self-regulating. Although a high purine diet may cause your body to excrete higher levels of vitamin C, don't forget that it will also increase production of uric acid, which is one of our most important antioxidants. Uric acid constitutes the antioxidant found in highest concentration in human blood, as it provides about half of the total antioxidant capacity of blood.
Equally, if you are following a moderate to low carbohydrate diet, the resulting stable blood sugar levels will decrease oxidative stress on your body. At the same time, your body's need for vitamin C is diminished, since vitamin C competes with glucose for entry into the cell via insulin receptors. Due to this mechanism, supplementing vitamin C to excess is far from harmless as it actually causes insulin resistance.
EDIT: "It has been noted that the loss of the ability to synthesize ascorbate strikingly parallels the inability to break down uric acid, also a characteristic of primates. Uric acid and ascorbate are both strong reducing agents. This has led to the suggestion that, in higher primates, uric acid has taken over some of the functions of ascorbate."
The problem using the Bellevue experiment and the SAD diet are similar in that they only apply to those who eat that diet. SAD eaters may need more vit C. ALL meat only dieters may need less. But for those in the middle, can we assume either applies to us? In fact, in both cases, we only know if people get scurvy or not but we don't know what is optimal. Since most humans actually do naturally prefer a varied omniverous diet, AND our dentition is designed for that, I am guessing that some vitamin C is optimal, even if it just means eating a few oranges per week and some veggies. I think people are going overboard with this fructose phobia. Yeah, don't eat a ton of it, but eating an orange twice per week is fine for most people.
Edited to add: Whoa, now here's something interesting! http://www.vitamincfoundation.org/forum/viewtopic.php?f=3&t=6086 Looks like about 30 % of the human population may be able to make enough vitamin C internally. Some people just don't get scurvy no matter what crap they eat! The rest seem like they will do fine as long as they eat meat which contains the hydroxyproline and hydroxylysine that we need vit C to make in the first place (thank you to the person who pointed this out in the other post, very interesting). Anyway, seems to me most will either be eating meat or getting vit C from fruit. Very few will fall through the cracks unless you are stuck on a boat at sea with mostly just biscuits. And even then, a certain percentage will make their own vit C and still not get scurvy.
I'm so glad this questions was asked as now I've learned two very interesting new things.
Depending on how much we need for real, broccoli seems like a real winner ~3 oz will get you almost 100%DV. If we don't need the DV there are some promising amounts in spinach and seaweed. You could also go wild with some dandelion greens.
Vegetables high in vitamin C include green peppers, broccoli, Brussels sprouts, cauliflower, cabbage, raw and cooked leafy greens, such as spinach and kale, as well as potatoes and winter squash. Livestrong
Though fructose may constitute a legitimate concern, couldn't low-sugar fruits (strawberries, grapefruit, lemon or lime juice added to marinades or sauces, etc.) provide a significant dose of Vitamin C without promotion of weight gain?
Supposedly raw meat contains the compound that our bodies make and need from Vit C. Sort of like the pre-cursor to Vit C. So our bodies get what they need from the meat and bypass the need for C.
I don't know a lot about this, or whether it is fact or speculation. If anyone knows, please chime in...
This is the basic idea: http://www.rawpaleoforum.com/infonews-items/vitamin-c-and-carnivorism/
the amount of vitamin c one needs for optimal health varies. in other animals vitamin C is an acute phase reactant and will easily increase twenty to thirty times if the animal is duly stressed. in humans of course this is impossible since we cannot ever consume much more that the ridiculously low RDA level that while prevents death due to the rapidly fatal scurvey will not prevent gingivitis and atherosclerosis in up to if not more than thirty percent of humans. personally i consume one gram a day in addition to the 250 milligrams i get in fresh raw fruit and vegetables and have done very good with my vascular health. even the pinguecula that are never supposed to just go away are almost gone. in scientific studies dogs are used to correlate the effects of diet on atherosclerosis yet dogs manufacture vitamin C. what the studies will not mention is that only one in 400 dogs can get atherosclerosis and their vitamin c levels are UNPUBLISHED. how damned convenient is that if you are trying to sell a statin drug?
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