Although a healthy food, corn by itself is not a nutritionally complete food. The people subsisting primarily on corn run the risk of developing pellagra, a vitamin B3 (niacin) deficiency. One way to avoid this is to eat it in tortilla form. Tortillas contain cornmeal and limestone potash, which facilitate the absorption of B3. Corn is a fine source of vitamin B1 (thiamine). It also is considered a good supplier of vitamin B5 (pantothenic acid), vitamins C, E, folic acid, and the minerals magnesium and phosphorus. Corn is considered to be low in protein content, as its levels of the amino acids lysine and trytophan are minimal. However, it is a good source of complex carbohydrate as well as healthful essential fatty acids and fiber.
Various flavonoids and carotenes are responsible for the varying colors of the different varieties of corn. Among the colors valued by the Native Americans were pink, red, black, and blue, and some varieties of corn also had stripes and spots. The concentration of these healthy phytochemicals is found in the outer layer of the endosperm, the nutritive tissue in seed plants. Yellow corn, the predominant corn used today, is high in the carotenoid called lutein. Thus, yellow corn food products can protect against heart disease and macular degeneration, a condition of the eye typically seen in older age; 1.5 mcg of lutein is found in one 31/2-oz (100 g) serving of yellow corn.