The nutritional value of egg yolk is higher than that of egg white. Every 100g egg yolk contains 7g protein, 5g fat 15g, 67mg calcium, 266mg phosphorus and 3.5mg iron. However, every 100g egg white only contains 5g of protein, 9mg of calcium, 8mg of phosphorus and 0. 1mg of iron. Egg yolk also contains a lot of choline, lecithin, cholesterol, rich vitamins and various trace elements, while egg white basically does not contain the above components.