Why are the prices different? Because the advertising costs of manufacturers are different.

Vitamins, also known as vitamins, are a kind of organic substances necessary to maintain human life activities and important active substances to maintain human health. The content of vitamins in the body is very small, but it plays an important role in the process of human growth, metabolism and development. Although the chemical structures and properties of various vitamins are different, they are similar as follows: ① Vitamins exist in food in the form of provitamins (vitamin precursors); ② Vitamins are not components of tissues and cells, and do not produce energy. Their function is mainly to participate in the regulation of metabolism. ③ Most vitamins can't be synthesized or the synthetic amount is not enough to meet the body's needs. You must always get it from food. (4) The demand for vitamins is very small, and the daily demand is often calculated in milligrams (mg) or micrograms (ug). However, once it is lacking, it will cause the corresponding vitamin deficiency and cause harm to human health. Vitamins, unlike carbohydrates, fats and protein, account for only a small proportion in natural foods, but they are also necessary for human body. Most vitamins cannot be synthesized in the body and must be taken from food. Vitamins themselves do not provide heat energy. Some vitamins, such as B6 and K, can be synthesized by bacteria in the intestinal tract of animals, and the synthetic amount can meet the needs of animals. Animal cells can convert tryptophan into nicotinic acid (a B vitamin), but the yield is not enough. Vitamin C can be synthesized by animals other than primates (including humans) and guinea pigs. Plants and most microorganisms can synthesize vitamins by themselves without external supply. Many vitamins are components of helper groups or coenzymes.