What is a commodity? Commodities with use value are called commodities. For example, sand and gravel are useless to ordinary residents, and they can only be called commodities, but they can only be called commodities to builders. Similarly, health care products are only for people to eat. If nutrients are what you want, they can be called commodities for you, and what you don't need is not commodities for you. Whether the nutritional components of cod liver oil blueberry pills are useful to you depends on your health. Cod liver oil contains vitamin D and vitamin A. People who lack calcium should take vitamin D instead of calcium, because usually all foods and rivers contain calcium, but calcium can only be absorbed under the action of vitamin D. Vitamin A can improve amblyopia and night blindness. Blueberries contain other vitamins and minerals, but there are many ways for people to get nutrition, such as eating oranges to get vitamin C, eating soy products to get vitamin A, synthesizing vitamin D [from cholesterol to vitamin D] in the sun, and synthesizing melatonin in the sun [the advertisement of calcium supplementation melatonin is a scam]. ...