What Is The Nutritional Value Of An Egg?

Eggs are an inexpensive source of high-quality protein. They are low in calories and are consumed as-is or as an ingredient in a wide variety of recipes, such as baked goods and sauces. Eggs are versatile and nutritious. Though they were once shunned due to their cholesterol content, most nutrition experts now agree that eggs can be a part of a healthful, balanced diet.

Basic Nutrient Values

One whole egg is the equivalent of 1 oz. of meat in terms of protein content. Egg protein contains all of the essential amino acids and it scores a perfect 100 for biological value, which is a value that measures how well the body can absorb and utilize a protein. It is second only to whey protein for its "completeness" as a protein source. One fresh whole large egg provides 72 calories and 5 g of fat, 2 g of saturated fat, 7 g of protein, 70 mg of sodium and 211 mg of cholesterol. Eggs do not contain any carbohydrates, sugars or dietary fiber. The cholesterol is contained in the yolk of the egg. Although egg yolks are high in cholesterol, they are rich in many essential nutrients.

Rich in B-Vitamins

Eggs are a particularly good food source of riboflavin, or vitamin B2, with one large egg providing 0.2 mg, or 15 percent of the Recommended Daily Value, or DV, for this nutrient. Riboflavin, like thiamin and niacin, works as a coenzyme in energy metabolism. Eggs are also rich in vitamin B12, which is necessary for making DNA and new cells and which also promotes a healthy nervous system. One large egg contains 0.6 micrograms, or mcg, meeting 25 percent of the DV for vitamin B12.

Brain Food

One of the reasons that an egg is often called a "brain food" is because it is one of the best food sources of a vitamin known as choline, according to the Choline Information website. The human body makes choline, but not in sufficient quantities to meet its needs without dietary sources. According to an article published in the May 2010 issue of the "Journal of Inherited Metabolic Disease," choline is a component of acetylcholine, a brain chemical, or neurotransmitter, that transmits messages to and from nerves and between nerves and muscles. It is an important component of two fat-like molecules in the brain that are necessary for proper brain function.

Minerals

Eggs are a good food source of several essential minerals, including phosphorus. One whole large egg meets 14 percent of the DV for this nutrient. Phosphorus is essential for strong, healthy bones and teeth and the synthesis of DNA. Eggs are also rich in the trace mineral selenium. One whole large egg contains about 15.8 mcg of selenium, meeting 28 percent of the DV. Selenium helps prevent damage to cells, strengthens the immune system and is necessary for regulating thyroid function.

Lutein

Egg yolks contain lutein, which is one of the carotenoids and an important antioxidant. Lutein-rich diets may be linked to a decreased risk of age-related macular degeneration. According to a research study published in the "Journal of Nutrition" in August 2004, the lutein found in egg yolks is thought to be more absorbable and usable by the body than other forms of this nutrient, such as that found in spinach.