In 2007, the magazine Mother Earth News decided to test that claim. They sent for pastured eggs from 14 farms around the U.S., tested them for a number of nutrients, and compared them to the figures listed in the USDA Nutrient Database for conventional eggs. Here are the results per 100 grams for conventional eggs, the average of all the pastured eggs, and eggs from Skagit River Ranch, which sells at my farmer's market:
Vitamin A:
- Conventional: 487 IU
- Pastured avg: 792 IU
- Skagit Ranch: 1013 IU
- Conventional: 34 IU
- Pastured avg: 136 - 204 IU
- Skagit Ranch: not determined
- Conventional: 0.97 mg
- Pastured avg: 3.73 mg
- Skagit Ranch: 4.02 mg
- Conventional: 10 mcg
- Pastured avg: 79 mcg
- Skagit Ranch: 100 mcg
- Conventional: 0.22 g
- Pastured avg: 0.66 g
- Skagit Ranch: 0.74 g
Looks like the American Egg Board and the Egg Nutrition Council have some egg on their faces...
Eggs also contain vitamin K2, with the amount varying substantially according to the hen's diet. Guess where the A, D, K2, beta-carotene and omega-3 fatty acids are? In the yolk of course. Throwing the yolk away turns this powerhouse into a bland, nutritionally unimpressive food.
It's important to note that "free range" supermarket eggs are nutritionally similar to conventional eggs. The reason pastured eggs are so nutritious is that the chickens get to supplement their diets with abundant fresh plants and insects. Having little doors on the side of a giant smelly barn just doesn't replicate that. ADS LINK 200 X 90