Minute Maid Co, the US juice company, has announced it is to introduce the first national brand of vitamin-D-fortified juice, in a move being seen as the next move in the race to capture the health drink market. PepsiCo's Tropicana unit is seen as its main rival. Minute Maid, a unit of Coca-Cola Co, said vitamin D - which aids the body's absorption of calcium and helps prevent osteoporosis - will be added to Minute Maid calcium-fortified premium homestyle-squeezed orange juice, as well as some of Minute Maid's calcium-fortified juice blends, from the beginning of April.