A dietary supplement is a product that is intended to supplement the diet and provide essential nutrients such as vitamins, minerals, and other dietary components. The two crossword solutions for the term 'dietary supplement' are IRON (4 letters) and VITAMIN (7 letters). IRON is an essential mineral that helps to transport oxygen throughout the body and is important for healthy red blood cells. VITAMIN is a general term for a group of organic compounds that are essential for normal growth and development. Vitamins are found in many foods and can also be taken as supplements.