Phosphoric acid is used as a preservative in a number of different beverages and foods, including Coca-Cola and similar products. According to WebMD, some health officials link the use of phosphoric acid to an increase in the number of cases of people developing osteoporosis.
The Coca-Cola Company states that phosphoric acid is completely safe for human consumption and helps give its drink products their signature tartness while also serving as a preservative. The company cites that its use is approved by health official in all nations that sell the company's products.
However, some health officials state that because many people substitute drinking colas like Coca-Cola for other healthier drinks, there are more cases of people suffering from bone density loss. While phosphorus is a key building block for bones, not getting enough calcium, such as from drinking milk products, can actually lower a person's bone density.