For more than 5,000 years, humans have enjoyed what may be one of nature’s most convenient and nutritious foods — the egg. Today per-person consumption averages around 300 eggs a year. Why eggs are healthy? Eggs provide high protein content for relatively low cost. They’re also relatively low in calories — one medium-sized egg contains just 78 calories. Eggs contain vitamins B12, C, D, E, and K, as well as the minerals iron and zinc. They’re also a rich source of choline, important for brain functioning and health.