The point is (and it's a good one), does it matter?
A good example are the statin drugs. Drug companies did a lot of marketing around "well, our drug lowers LDL by 10% more than our competitor", which could be very well be true, but again, does that matter?
Unless you run studies that measure an outcome that matters, it's all conjecture. Vitamin C levels might be declining, but we don't have a issue with scurvy in developed nations, the impact of any decline might be insignificant.
A good example are the statin drugs. Drug companies did a lot of marketing around "well, our drug lowers LDL by 10% more than our competitor", which could be very well be true, but again, does that matter?
Unless you run studies that measure an outcome that matters, it's all conjecture. Vitamin C levels might be declining, but we don't have a issue with scurvy in developed nations, the impact of any decline might be insignificant.