Nutritional supplement market Rexall Sundown sold its Boca Raton office building to Butters Construction & Development, which will spend $3.5 million on renovations and upgrades. The company, a subsidiary of Sundown Naturals in Bohemia, New York, sold the 59,264-square-foot office on 5 acres at 851 N.W. Broken Sound Parkway for $6.125 million to Coconut Creek-based Butters. Rexall Sundown will keep its corporate offices in the building, said Adam Vaisman, director of acquisitions for Butters. The...