When maize was initially cultivated in the Americas, it was grown along with beans and squash. The beans used the stalks of the maize to support themselves as they grew, while the squash offered a ground cover. The combination was also healthy for the soil, which was additionally enriched with alkaline substances. The addition of alkali to the soil proved to be an important part of growing maize, as alkali frees up niacin in the grain. When maize was initially exported to other regions, many people suffered from pellagra, or niacin deficiency, until the problem was identified and corrected.