Why take nutritional supplements? (Dr Low Dog)

Health-conscious consumers read nutritional labels, but it's nearly impossible to get the nutrients we need with diet alone. To get the USDA-recommended daily quota of vitamin D, for example, you need to eat 15 eggs or 26 sardines; of iron, 414 almonds or 15 cups of broccoli. So we rely on nutritional supplements—vitamins and minerals, probiotics and enzymes—but the variety of pills, products, and elixirs on the market today is overwhelming.