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Vitamins don’t yield energy directly as carbohydrates, proteins and fats do. Yet, as the root of the word “vitamin” indicates, they are vital. As is the case for all vitamins, your body only requires small amounts of B vitamins, including vitamin B-12. And like many vitamins, B-12 works as a team player to regulate body processes and keep you healthy and energetic.
Scientists generally classify nine vitamins as water-soluble and four as fat-soluble. Fat-soluble vitamins need fat to be absorbed or transported in your body, and any excess tends to get stored in fatty tissues. In contrast, water-soluble vitamins readily travel in your bloodstream, and your body can more easily excrete any excess in your urine. In the water-soluble category, vitamin C is the only non-B-complex vitamin, while B-12 and the remaining seven vitamins belong to the B-complex group.
Your body uses vitamin B-12 in different forms, all of which are attached to the mineral cobalt. You might even hear the terms vitamin B-12 and cobalamins used interchangeably. Its active forms in human metabolism are methylcobalamin and 5-deoxyadenosylcobalamin. Vitamin B-12 is key to a number of processes, including amino acids and fatty acids metabolism, nerve cell function and synthesis of DNA, the genetic “blueprint” in every cell of your body. It also works with folate — another B vitamin — to help your body make red blood cells.
Most multivitamin supplements contain B-12. Alternatively, you can look for B-complex supplements or isolated vitamin B-12 preparations. In some cases of anemia or nerve dysfunction, a doctor may recommend prescription-strength B-12 as an injection or a nasal gel. The Linus Pauling Institute estimates that most over-the-counter or prescription preparations contain B-12 in the form cyanocobalamin, although you may also find methylcobalamine in some products. Your body must convert cyoanocobalamin into its active forms before using it.
According to the Linus Pauling Institute, only bacteria can make vitamin B-12; it doesn’t naturally occur in plants. Animal products are the richest sources of B-12, including liver, whole milk, eggs, oysters, shrimp and chicken. Many foods, particularly cereals, are also fortified with B-12. Natural, food-based B-12 usually occurs bound to protein, so your body must separate it in the stomach before use. In contrast, the manmade B-12 in fortified foods or supplements occurs in free form.
Article reviewed by Leon Teeboom Last updated on: Nov 1, 2012