If you actually look at the RDA and Compare to your typical diet you'll find you're way under. At least I was and I eat reasonably well.
I've actually noticed a lot of health benefits since I start taking higher doses of vitamin c.
[1] http://nutritiondata.self.com/facts/fruits-and-fruit-juices/...
[2] http://nutritiondata.self.com/facts/fruits-and-fruit-juices/...
[3] http://nutritiondata.self.com/facts/fruits-and-fruit-juices/...
So now we're just talking about dose, symptoms, and lifestyle. Whether it's an orange or a supplement, the vitamin C still works.
Some studies indicate that a fairly high proportion of the population has "sub-clinical" vitamin deficiency, e.g., in C. I used to get nosebleeds pretty often. I have a diet that's very low in fruits and vegetables. When I started taking C, my nosebleeds went away immediately. I'd rather take the supplement than incorporate fruits and vegetables into my diet.
If you have a deficiency, yes, you need to take more of that particular vitamin. But the evidence is against people without a deficiency taking a general purpose vitamin. A good pointer to recent studies: https://sciencebasedmedicine.org/more-evidence-that-routine-...
Yes, but (a) your body's ability to do this decreases as you age, and (b) sun exposure has other downsides such as increased risk of skin cancer, so there's a tradeoff involved.
Stop clinging to that as a reason to shelter indoors and replace life with vitamins and manufactured meals.
Different people's skins have different sensitivities. Also, skin cancer doesn't happen in one exposure; the risk builds up over time.
> Stop clinging to that as a reason to shelter indoors and replace life with vitamins and manufactured meals.
Stop making assumptions. I personally have dark enough skin that a reasonable amount of sun exposure doesn't bother me. But that apparently didn't stop my vitamin D from being low (see my post elsewhere in this thread), so evidently I am dealing with the other thing I mentioned, the fact that your body's ability to make vitamin D from sun exposure decreases with age. So I started taking a supplement. Would you rather I just let my vitamin D be too low no matter how much sun I got?