Yes, eggs are one of the very best sources of vitamin D, although it goes without saying that their vitamin D content depends on the diet of the laying hens. Vitamin D is often called the "sunshine vitamin" and is required to support the activation of the immune system and for many other healthy bodily functions. Thus, though sunlight is such a major source of this vitamin, eggs become an important dietary source in some cases, especially for people who spend little time outdoors.
This means that eggs, particularly yolks, are a naturally occurring source of vitamin D as fat-soluble vitamins tend to store themselves in the egg's fatty portion. On an average, one yolk may contain around 10 to 20 IU of vitamin D, though this varies. The required dietary allowance for adults is around 600 to 800 IU of vitamin D per day, so eggs may fill in a certain amount of dietary requirement of vitamin D.
