Grocery stores, it seems, put far more emphasis on visual appearance than nutritional value. This isn't surprising, since consumers typically select produce based almost entirely on appearance. Oranges from Florida, for example, are frequently dipped in a red dye that gives them a deeper, more saturated orange color preferred by consumers. The only problem is that this orange dye has been banned by the FDA for use in foods due to its proven cancer-causing ability. But the Florida orange industry gets away with using the dye by claiming it's only used outside the orange, not inside. With that strange caveat, the FDA allows its use.
The dramatic decline in measurable levels of organic vitamins in grocery produce (the UK study mentioned above is just one of dozens of such studies) blows away the old medical myth that, "You can get all the nutrition you need from three square meals a day..." or, "Nobody needs vitamin supplements to be healthy." A critical review of the available food supply reveals that relying on it for adequate nutrition is a life threatening mistake that inevitably leads to chronic diseases like cancer and diabetes. The foods simply don't have the nutrition they used to, and grocery store produce is a poor source of organic vitamins.
One solution, of course, is to purchase and consume organic produce. Repeated tests have shown organic produce to be far more nutritious in terms of its levels of vitamins and minerals. Unfortunately, organic produce is more expensive and visually less appealing than traditionally-raised produce, so most consumers avoid it.
A better solution, and the one I strongly recommend and follow on a daily basis, is to stop thinking of the national food supply as a source of nutrition and start supplementing your diet with superfoods and organic vitamin supplements (whole food supplements). This is the only way you'll get adequate nutrition. Here are the best superfoods for this purpose: barley grass, chlorella, spirulina, sea vegetables, wheat grass, "greens" powders, quinoa, flax oil, extra virgin coconut oil, soy milk and tofu, green tea, amazon herbs, and various whole food vitamin supplements. This is where a healthy person gets their nutrition these days. Avoid all isolated vitamins like bottles of vitamin C tablets because, after all, most of those vitamins are synthetically produced. Instead, get all your organic vitamins and minerals from whole food supplements and superfoods. Interestingly, the best sources for organic vitamins are whole food supplements that won't even list their vitamin and mineral content. Instead, they just list the superfood ingredients like wheat grass, chlorella, and so on. You have to know enough about nutrition to figure out that these supplements are naturally very high in organic vitamins, minerals, essential fatty acids and health-enhancing phytochemicals.