Simplify the following text for a Grade 8 native English-speaking person.
Original: Dietary niacin deficiency tends to occur only in areas where people eat corn ( maize ) , the only grain low in niacin , as a staple food , and that do not use lime during meal\/flour production .
Simplified: It also tends to occur in areas where people eat maize ( corn , the only grain low in niacin ) as a staple food .