What is the effect and daily recommended amount of vitamin B12?

Vitamin B12, also known as cobalamin, is usually considered as a micronutrient that helps you provide energy. Vitamin B12 has many functions in the body. It is necessary for red blood cell production, cell metabolism, DNA formation and nerve function. B12 also helps the body metabolize fat, protein and carbohydrate, so it is necessary for digestion and absorption.

The human body cannot produce B12, so B12 is considered as an essential nutrient and must be obtained from diet or supplements. Although the human body can store B12 in the liver, it is still necessary to ensure that the intake of vitamin B12 is sufficient to reduce the risk of deficiency.

B12 is a water-soluble vitamin that naturally exists in many different foods. This vitamin mainly exists in animal foods, including but not limited to fish, meat, poultry, eggs and dairy products. Foods rich in B12 include liver, sardine and clams. Many food companies strengthen or add B12 during processing, such as breakfast cereal. B12 also exists in some plant foods, such as mushrooms and algae, but its bioavailability is far less than that of B12 in animal foods. This means that it is difficult for your body to digest and absorb B12 in plants.

Because of this, many people who follow a plant-based or vegan diet must take supplements to meet B12 needs, because they do not get enough vitamins from food. This is especially true for vegan athletes, because their diet does not contain B12 by default. It is essential to eat fortified foods, supplements and injections. The recommended daily intake of vitamin B12 is 2.4 micrograms per day.

If the diet is balanced, most people can get enough B12 every day, especially if their diet contains animal products. For example, a 3-ounce thin steak (about the size of a pack of playing cards) contains nearly 7 micrograms of B12.
Because many functions of the human body need vitamin B12, lack of B12 will lead to many health problems. For example, anemia can lead to nervous system dysfunction over time. There are many signs of B12 deficiency, which tend to develop slowly and gradually deteriorate over time. Early symptoms include fatigue, loss of appetite (which may lead to weight loss), pain in the mouth or tongue, nausea, vomiting, and depression. The late symptoms of B12 deficiency include vision problems, speech difficulties and numbness of hands and feet. Athletes with poor or deficient vitamin B12 nutrition may reduce the ability of high-intensity sports.

Because B12 is essential for many different body processes, many people believe that taking or taking extra B12 can help increase energy. Part of the reason for this theory may be that B12 plays a role in body energy production mainly through the formation of DNA. However, there is no strong scientific evidence to support this theory in people with sufficient vitamins. In other words, if you don't lack, you don't need to supplement. The best way to replenish energy is to eat various foods rich in B12, such as meat, dairy products and fortified cereals.